Vladimir Putin on Climate Change

We need to take into consideration all the bombs Loree McBride is dropping! That is a LOT OF POLLUTION. I do think we need to be concerned, first and foremost, with Loree McBride’s space fleet dropping bombs filled with deadly germs on the population. THAT IS THE MOST IMPORTANT ENVIRONMENTAL DISASTER OF OUR TIMES.

CHECK OUT THE FEEDS OF ONE SKEPTIC SCIENTIST & NASA WHO REGULARLY PUBLISH REPORTS ABOUT CLIMATE CHANGE TOWARDS THE BOTTOM OF THIS PAGE.

I am uncertain how I feel about the claim made by scientists that emissions cause global warming. But I certainly feel that if we can make less pollution that is always a good thing, even if the pollution does not cause global warming. I also know that Jesuits have in the past put contaminants in gasoline to deliberately pollute the air to make their enemies sick. Our most urgent environmental hazard are Jesuits who willingly and knowingly pollute as a form of biological/chemical warfare! So, for this reason, I appreciate leaders who care about the environment, because they will probably have my passion to STOP LOREE MCBRIDE’S BOMBS! Trump seems to not care about this AT ALL.

Putin says climate change not caused by emissions: https://phys.org/news/2017-03-putin-climate-emissions.html

AND https://www.france24.com/en/20170331-russian-president-vladimir-putin-says-humans-not-responsible-climate-change

CHRISTIAN SCIENTIST WHO BELIEVES IN CLIMATE  CHANGE: http://www1.cbn.com/cbnnews/healthscience/2015/July/Christians-Who-Believe-in-Climate-Change


CLIMATE SCIENTIST JUDITH CURRY’S FEED ON THE SUBJECT:

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  • The big ‘cancel’
    by Judith Curry We need to allow all voices to be heard. Like everyone else on the planet, I have been riveted by the events of the past week.  And I have been suffering from a great deal of cognitive … Continue reading →
  • COVID-19: why did a second wave occur even in regions hit hard by the first wave?
    By Nic Lewis  Introduction Many people, myself included, thought that in the many regions where COVID-19 infections were consistently reducing during the summer, indicating that the applicable herd immunity threshold had apparently been crossed, it was unlikely that a major … Continue reading →
  • Biden Administration II
    by Judith Curry Just as everyone was heaving a sigh of relief that 2020 is over, 2021 is providing some fresh craziness. We clearly need a new thread on this topic, but I have about 15 minutes today to spend … Continue reading →
  • Looking forward: new technologies in the 2020’s
    by Judith Curry Looking ahead towards new energy technologies, plus my own saga and rationale for transitioning my personal power generation and consumption. Happy New Year everyone!  The theme I decided for my post to ring in the New Year … Continue reading →
  • The relative infectivity of the new UK variant of SARS-CoV-2
    By Nic Lewis Key points A new variant, B.1.1.7, of the SARS-CoV-2 virus has recently spread rapidly in England The public health agency’s best estimate of B.1.1.7’s weekly growth rate advantage is 1.51x They mis-convert this in a reproduction number … Continue reading →
  • 2020 Year in Review
    by Judith Curry A year ago, there were many things about 2020 that no one anticipated. A few reflections on 2020.  Are there any insights to be gleaned from this crazy year? 1.Falsification of WHO’s prediction:   “Climate change is the … Continue reading →
  • Asymptomatic spread(?) of Covid-19
    by Judith Curry I just finished reading an article entitled Asymptomatic Spread Revisited. A new article in Nature [link] based on an extremely extensive and thorough analysis in Wuhan found no cases of asymptomatic transmission.  Cynically, comments on this paper … Continue reading →
  • The blame game
    by Judith Curry How the ‘blame game’ gets in the way of solving complex societal problems. An essay on how attempting to identify  blame for complex societal problems can get in the way of finding solutions to these problems.  What … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye these past 10 (!) weeks Politics-free thread, please! Climate science Partitioning climate projection uncertainty with multiple large ensembles and CMIP5/6 [link] How changing content of clouds could influence climate change … Continue reading →
  • Biden administration
    by Judith Curry I’ve received requests for a new politics discussion thread. Apart from some remaining challenges to the election results, the transition to the Biden administration is underway. Cabinet members are being named [link] Notably, John Kerry  will serve … Continue reading →
  • Five rules for evidence communication
    by Judith Curry “Avoid unwarranted certainty, neat narratives and partisan presentation; strive to inform, not persuade.” I just spotted this Comment in Nature: Five rules for evidence communication.  Once I spotted co-author David Spiegenhalter, I knew this would be good.  … Continue reading →
  • Cultural motivations for wind and solar renewables deployment
    by Andy West “For me the question now is, now that we know that renewables can’t save the planet, are we going to keep letting them destroy it?”. – Michael Schellenberger Introduction There have been many technical analyses of Wind … Continue reading →
  • Slower decay of landfalling Hurricanes in a warmer world — really?
    by Frank Bosse A recent paper published in “Nature” made some excitement in the media, see here or here. In the paper by Li & Chakraborty (L&C 2020 thereafter), the authors find a statistically significant increase of the decay time … Continue reading →
  • Disconnect in the relationship between GMST and ECS
    by Kenneth Fritsch Abstract. An analysis is presented of  he disconnection between the CMIP5 and CMIP6 Historical and Future periods when considering the relationship of the individual model GMST changes and the climate sensitivity. I have included a simple model … Continue reading →
  • U.S. election discussion thread
    by Judith Curry No words. The only thing crazier than the U.S. election is this morning’s hurricane forecast. I have no words re the election.  For a diversion, here is my hurricane forecast for Eta. Summary:  current: TERRIBLE.  forecast: CRAZY … Continue reading →
  • Science and politics
    by Judith Curry “I’m reaching out to scientists this week about the election. How do you feel about it? Which of the candidates has the best plan, for you, in science and technology?” The above question was emailed to me … Continue reading →
  • Climate science and the Supreme Court
    by Judith Curry An alternative assessment of U.S. Supreme Court Justice nominee Amy Coney Barrett’s statements on climate change. For those of you not in the U.S., confirmation hearings on the nomination of Amy Coney Barrett for the Supreme Court … Continue reading →
  • T cell cross-reactivity and the Herd immunity threshold
    By Nic Lewis An interesting new paper by Marc Lipsitch and co-authors, “Cross-reactive memory T cells and herd immunity to SARS-CoV-2”, has recently been published.[1] It discusses immunological and epidemiological aspects and implications of pre-existing cross-reactive adaptive immune system memory … Continue reading →
  • What the pandemic has taught us about science
    The scientific method remains the best way to solve many problems, but bias, overconfidence and politics can sometimes lead scientists astray It’s been awhile since I have been so struck by an article that I felt moved to immediately do … Continue reading →
  • How we fool ourselves
    by Judith Curry Crowd sourcing examples of fallacious thinking from climate science. While I have been very busy, I have kept the Denizen’s entertained with threads on politics and cancel culture.  Lets face it, that stuff has been on all … Continue reading →
  • Politics discussion thread II
    by Judith Curry Looks like we need a new thread on this. I’m still crazy busy but doing my best to keep the blog rolling along.  Thanks for your continued participation!
  • Herd immunity to COVID-19 and pre-existing immune responses
    By Nic Lewis I showed in my May 10th article Why herd immunity to COVID-19 is reached much earlier than thought that inhomogeneity within a population in the susceptibility and in the social-connectivity related infectivity of individuals would reduce, in my … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that have caught my eye this past 12(!) weeks. Pattern Recognition Methods to Separate Forced Responses from Internal Variability in Climate Model Ensembles and Observations https://journals.ametsoc.org/jcli/article/33/20/8693/353735/Pattern-Recognition-Methods-to-Separate-Forced… An increase in global trends of tropical cyclone … Continue reading →
  • FIRE
    by Judith Curry Subtitle: our failure to live in harmony with nature. I’m taking a breather today from nonstop hurricane stuff. Well, ‘breather’ may not be quite the right word. As I’m writing this, I’m looking out into the smoke … Continue reading →
  • COVID-19: evidence shows that transmission by schoolchildren is low
    By Nic Lewis Much fuss has been made in the UK, not least by teachers’ unions, about recommencing physical school attendance. As this issue applies to many countries, I thought it worth highlighting research findings in Europe. While it is … Continue reading →
  • Part of the heat is coming from beneath our feet.
    by Judith Curry A thought-provoking article  from my new favorite blog, The Ethical Skeptic. The Ethical Skeptic My new favorite blog is The Ethical Skeptic.  From the About page: “It is the intent of this author and purpose of this … Continue reading →
  • Politics discussion thread
    by Judith Curry It’s time for a politics thread, to deflect the political comments that are sneaking into the technical threads. Have at it.  U.S. presidential politics is an obvious topic.  Interesting things going on in Europe and Australia and … Continue reading →
  • New confirmation that climate models overstate atmospheric warming
    by Ross McKitrick Two new peer-reviewed papers from independent teams confirm that climate models overstate atmospheric warming and the problem has gotten worse over time, not better. The papers are Mitchell et al. (2020) “The vertical profile of recent tropical … Continue reading →
  • New paper suggests historical period estimates of climate sensitivity are not biased low by unusual variability in sea surface temperature patterns
    By Nic Lewis An important new paper by Thorsten Mauritsen, Associate Professor at Stockholm University[i] and myself has just been accepted for publication (Lewis and Mauritsen 2020)[ii]. Its abstract reads: Recently it has been suggested that natural variability in sea … Continue reading →
  • Emergent constraints on TCR and ECS from historical warming in CMIP5 and CMIP6 models
    By Nic Lewis This is a brief comment on a new paper[i] by a mathematician in the Exeter Climate Systems group, Femke Nijsse, and two better known colleagues, Peter Cox and Mark Williamson. I note that Earth Systems Dynamics published … Continue reading →
  • Cancel culture discussion thread II
    by Judith Curry Some additional articles and events to discuss. This is a bit thin, but we needed a new thread and I am short of time. Cliff Mass fired by NPR from his local radio show [link] The cancel … Continue reading →
  • Why herd immunity to COVID-19 is reached much earlier than thought – update
    By Nic Lewis I showed in my May 10th article Why herd immunity to COVID-19 is reached much earlier than thought that inhomogeneity within a population in the susceptibility and in the social-connectivity related infectivity of individuals would reduce, in my … Continue reading →
  • Apocalypse Never and False Alarm
    by Judith Curry Two important new books to discuss. Apocalypse Never: Why Environmental Alarm Hurts Us All, by Michael Schellenberger [amazon]   ‘Best Seller’ Schellenberger’s op-ed:  On Behalf of Environmentalists I Apologize For the Climate Scare [link]  originally published at Forbes, … Continue reading →
  • Cancel culture discussion thread
    by Judith Curry A change of topic. I’m running out of steam on COVID-19.  Still collecting articles, we’ll see if i do any more threads on that topic (of course I hope that Nic will have some new analyses for … Continue reading →
  • Covid discussion thread: Part X
    by Judith Curry Latest roundup of interesting articles.  I’m running out of steam on this topic, here are some random articles I’ve flagged over the last few weeks. New study in Spain addes evidence against herd immunity [link] Very good … Continue reading →
  • The progress of the COVID-19 epidemic in Sweden: an analysis
    By Nic Lewis The course of the COVID-19 pandemic in Sweden is of great interest, as it is one of very few advanced nations where no lockdown order that heavily restricted people’s movements and other basic freedoms was imposed. As … Continue reading →
  • Mass spectrometry and climate science. Part II
    by Roland Hirsch New technologies in mass spectrometry are advancing research in climate science This is the second of a two-part posting based on a presentation prepared for the American Chemical Society’s National Meeting in March 2020. The meeting was … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye the past 7(!) weeks. The future of the carbon cycle in a changing climate [link] Trends in weather ‘pleasantness’ [link] Misconceptions of global catastrophe [link] Over 15-30 years, internal variability … Continue reading →
  • Did lockdowns really save 3 million COVID-19 deaths, as Flaxman et al. claim?
    By Nic Lewis Key points about the recent Nature paper by Flaxman and other Imperial College modellers 1) The transition from rising to declining recorded COVID-19 deaths in the in 11 European countries that they studied imply that transmission of … Continue reading →
  • Structural errors in global climate models
    by Gerald Browning Climate model sensitivity to CO2 is heavily dependent on artificial parameterizations (e.g. clouds, convection) that are implemented in global climate models that utilize  the wrong atmospheric dynamical system and excessive dissipation. The peer reviewed manuscript entitled “The … Continue reading →
  • Mass spectrometry and climate science. Part I: Determining past climates
    by Roland Hirsch Mass spectrometry is essential for research in climate science. Understanding climate requires having sufficient knowledge about past climate and about the important factors that are influencing climate today, so that reliable models can be developed to predict … Continue reading →
  • Covid discussion thread: Part IX
    by Judith Curry Some interesting articles that I’ve spotted recently. This is really a fantastic manuscript on what we know today about #COVID19 biology and immunology. https://cell.com/immunity/pdf/S1074-7613(20)30183-7.pdf Fine COVID19 seroprevalence study in hard-hit Geneva finds peak at 10·8%. Also, for … Continue reading →
  • Dynamics of the Tropical Atmosphere and Oceans
    by Judith Curry Peter Webster’s magnum opus is now published: Dynamics of the Tropical Atmosphere and Oceans. From the blurb on amazon.com: “This book presents a unique and comprehensive view of the fundamental dynamical and thermodynamic principles underlying the large … Continue reading →
  • Covid discussion thread: Part VIII
    by Judith Curry Interesting papers that I’ve recently spotted COVID-19 can last for several months [link] At present, the evidence is pointing tentatively to a chain of person-to-person infections occurring somewhere outside a city before somebody brought the virus to … Continue reading →
  • When does government intervention make sense for COVID-19?
    By Nic Lewis Introduction I showed in my last article that inhomogeneity within a population in the susceptibility and infectivity of individuals would reduce the herd immunity threshold, in my view probably very substantially, and that evidence from Stockholm County … Continue reading →
  • COVID-19 discussion thread VII
    by Judith Curry Some interesting papers that I’ve spotted over the past week. New study from S. Korea finds HCQ +AZ (or other antibiotic) significantly reduces time to viral clearance and hospital stay in moderate covid-19 patients compared to both … Continue reading →
  • Culturally-determined response to climate change: Part III
    by Andy West Climate change affirmative responses to all survey questions are culturally determined, and across National Publics related to religiousity.  Cultural attitudes inappropriately push climate policy.  Introduction Post one of this series demonstrated a strong correlation across nations between … Continue reading →
  • Greening the planet and slouching towards Paris?
    by Patrick J. Michaels A new paper finds higher than expected CO2 fertilization inferred from leaf to global observations.  The paper predicts that the Earth is going to gain nearly three times as much green matter as was predicted by … Continue reading →
  • Why herd immunity to COVID-19 is reached much earlier than thought
    By Nic Lewis Introduction A study published in March by the COVID-19 Response Team from Imperial College (Ferguson20[1]) appears to have been largely responsible for driving government actions in the UK and, to a fair extent, in the US and … Continue reading →
  • COVID discussion thread VI
    by Judith Curry A roundup of interesting articles on COVID-19.   A new, experimental wearable device is capable of catching early signs and symptoms associated with the coronavirus. [link] Lets have an honest debate about herd immunity [link] 47 old … Continue reading →

NASA GLOBAL CLIMATE CHANGE NEWS

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  • 2020 Tied for Warmest Year on Record, NASA Analysis Shows
    Earth’s global average surface temperature in 2020 tied with 2016 as the warmest year on record, according to an analysis by NASA. Continuing the planet’s long-term warming trend, the year’s globally averaged temperature was 1.84 degrees Fahrenheit (1.02 degrees Celsius) warmer than the baseline 1951-1980 mean, according to scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. 2020 edged out 2016 by a very small amount, within the margin of error of the analysis, making the years effectively tied for the warmest year on record. “The last seven years have been the warmest seven years on record, typifying the ongoing and dramatic warming trend,” said GISS Director Gavin Schmidt. “Whether one year is a record or not is not really that important – the important things are long-term trends. With these trends, and as the human impact on the climate increases, we have to expect that records will continue to be broken.” A Warming, Changing World Globally, 2020 was the hottest year on record, effectively tying 2016, the previous record. Overall, Earth’s average temperature has risen more than 2 degrees Fahrenheit since the 1880s. Temperatures are increasing due to human activities, specifically emissions of greenhouse gases, like carbon dioxide and methane. Credits: NASA’s Scientific Visualization Studio/Lori Perkins/Kathryn Mersmann Lee esta historia en español aquí. Rising temperatures are causing phenomena such as loss of sea ice and ice sheet mass, sea level rise, longer and more intense heat waves, and shifts in plant and animal habitats. Understanding such long-term climate trends is essential for the safety and quality of human life, allowing humans to adapt to the changing environment in ways such as planting different crops, managing our water resources and preparing for extreme weather events. Ranking the Records A separate, independent analysis by the National Oceanic and Atmospheric Administration (NOAA) concluded that 2020 was the second-warmest year in their record, behind 2016. NOAA scientists use much of the same raw temperature data in their analysis, but have a different baseline period (1901-2000) and methodology. Unlike NASA, NOAA also does not infer temperatures in polar regions lacking observations, which accounts for much of the difference between NASA and NOAA records. Like all scientific data, these temperature findings contain a small amount of uncertainty – in this case, mainly due to changes in weather station locations and temperature measurement methods over time. The GISS temperature analysis (GISTEMP) is accurate to within 0.1 degrees Fahrenheit with a 95 percent confidence level for the most recent period. Beyond a Global, Annual Average While the long-term trend of warming continues, a variety of events and factors contribute to any particular year’s average temperature. Two separate events changed the amount of sunlight reaching the Earth’s surface. The Australian bush fires during the first half of the year burned 46 million acres of land, releasing smoke and other particles more than 18 miles high in the atmosphere, blocking sunlight and likely cooling the atmosphere slightly. In contrast, global shutdowns related to the ongoing coronavirus (COVID-19) pandemic reduced particulate air pollution in many areas, allowing more sunlight to reach the surface and producing a small but potentially significant warming effect. These shutdowns also appear to have reduced the amount of carbon dioxide (CO2) emissions last year, but overall CO2 concentrations continued to increase, and since warming is related to cumulative emissions, the overall amount of avoided warming will be minimal. The largest source of year-to-year variability in global temperatures typically comes from the El Nino-Southern Oscillation (ENSO), a naturally occurring cycle of heat exchange between the ocean and atmosphere. While the year has ended in a negative (cool) phase of ENSO, it started in a slightly positive (warm) phase, which marginally increased the average overall temperature. The cooling influence from the negative phase is expected to have a larger influence on 2021 than 2020. “The previous record warm year, 2016, received a significant boost from a strong El Nino. The lack of a similar assist from El Nino this year is evidence that the background climate continues to warm due to greenhouse gases,” Schmidt said. The 2020 GISS values represent surface temperatures averaged over both the whole globe and the entire year. Local weather plays a role in regional temperature variations, so not every region on Earth experiences similar amounts of warming even in a record year. According to NOAA, parts of the continental United States experienced record high temperatures in 2020, while others did not. In the long term, parts of the globe are also warming faster than others. Earth’s warming trends are most pronounced in the Arctic, which the GISTEMP analysis shows is warming more than three times as fast as the rest of the globe over the past 30 years, according to Schmidt. The loss of Arctic sea ice – whose annual minimum area is declining by about 13 percent per decade – makes the region less reflective, meaning more sunlight is absorbed by the oceans and temperatures rise further still. This phenomenon, known as Arctic amplification, is driving further sea ice loss, ice sheet melt and sea level rise, more intense Arctic fire seasons, and permafrost melt. This plot shows yearly temperature anomalies from 1880 to 2019, with respect to the 1951-1980 mean, as recorded by NASA, NOAA, the Berkeley Earth research group, and the Met Office Hadley Centre (UK). Though there are minor variations from year to year, all five temperature records show peaks and valleys in sync with each other. All show rapid warming in the past few decades, and all show the past decade has been the warmest. › Full image and caption Land, Sea, Air and Space NASA’s analysis incorporates surface temperature measurements from more than 26,000 weather stations and thousands of ship- and buoy-based observations of sea surface temperatures. These raw measurements are analyzed using an algorithm that considers the varied spacing of temperature stations around the globe and urban heating effects that could skew the conclusions if not taken into account. The result of these calculations is an estimate of the global average temperature difference from a baseline period of 1951 to 1980NASA measures Earth's vital signs from land, air, and space with a fleet of satellites, as well as airborne and ground-based observation campaigns. The satellite surface temperature record from the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s Aura satellite confirms the GISTEMP results of the past seven years being the warmest on record. Satellite measurements of air temperature, sea surface temperature, and sea levels, as well as other space-based observations, also reflect a warming, changing world. The agency develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. NASA shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet. NASA’s full surface temperature data set – and the complete methodology used to make the temperature calculation – are available at: https://data.giss.nasa.gov/gistemp GISS is a NASA laboratory managed by the Earth Sciences Division of the agency’s Goddard Space Flight Center in Greenbelt, Maryland. The laboratory is affiliated with Columbia University’s Earth Institute and School of Engineering and Applied Science in New York. For more information about NASA’s Earth science missions, visit: https://www.nasa.gov/earth
  • Land Ecosystems Are Becoming Less Efficient at Absorbing Carbon Dioxide
    Plants play a key role in mitigating climate change. The more carbon dioxide they absorb during photosynthesis, the less carbon dioxide remains trapped in the atmospherem, where it can cause temperatures to rise. But scientists have identified an unsettling trend – 86% of land ecosystems globally are becoming progressively less efficient at absorbing the increasing levels of CO2 from the atmosphere. Credit: NASA's Goddard Space Flight Center/Scientific Visualization Studio/Katy Mersmann [transcript] Land ecosystems currently play a key role in mitigating climate change. The more carbon dioxide (CO2) plants and trees absorb during photosynthesis, the process they use to make food, the less CO2 remains trapped in the atmosphere, where it can cause temperatures to rise. But scientists have identified an unsettling trend – as levels of CO2 in the atmosphere increase, 86% of land ecosystems globally are becoming progressively less efficient at absorbing it. Because CO2 is a main "ingredient" that plants need to grow, elevated concentrations of it cause an increase in photosynthesis, and consequently, plant growth – a phenomenon aptly referred to as the CO2 fertilization effect, or CFE. CFE is considered a key factor in the response of vegetation to rising atmospheric CO2 as well as an important mechanism for removing this potent greenhouse gas from our atmosphere – but that may be changing. For a new study published Dec. 10 in Science, researchers analyzed multiple field, satellite-derived and model-based datasets to better understand what effect increasing levels of CO2 may be having on CFE. Their findings have important implications for the role plants can be expected to play in offsetting climate change in the years to come. “In this study, by analyzing the best available long-term data from remote sensing and state-of-the-art land-surface models, we have found that since 1982, the global average CFE has decreased steadily from 21% to 12% per 100 ppm of CO2 in the atmosphere,” said Ben Poulter, study co-author and scientist at NASA’s Goddard Space Flight Center. “In other words, terrestrial ecosystems are becoming less reliable as a temporary climate change mitigator.” What’s Causing It? Without this feedback between photosynthesis and elevated atmospheric CO2, Poulter said we would have seen climate change occurring at a much more rapid rate. But scientists have been concerned about how long the CO2 Fertilization Effect could be sustained before other limitations on plant growth kick in. For instance, while an abundance of CO2 won’t limit growth, a lack of water, nutrients, or sunlight – the other necessary components of photosynthesis — will. To determine why the CFE has been decreasing, the study team took the availability of these other elements into account. “According to our data, what appears to be happening is that there’s both a moisture limitation as well as a nutrient limitation coming into play,” Poulter said. “In the tropics, there’s often just not enough nitrogen or phosphorus, to sustain photosynthesis, and in the high-latitude temperate and boreal regions, soil moisture is now more limiting than air temperature because of recent warming.” In effect, climate change is weakening plants’ ability to mitigate further climate change over large areas of the planet. Next Steps The international science team found that when remote-sensing observations were taken into account – including vegetation index data from NASA's Advanced Very High Resolution Radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments – the decline in CFE is more substantial than current land-surface models have shown. Poulter says this is because modelers have struggled to account for nutrient feedbacks and soil moisture limitations – due, in part, to a lack of global observations of them. “By combining decades of remote sensing data like we have done here, we’re able to see these limitations on plant growth. As such, the study shows a clear way forward for model development, especially with new remote sensing observations of vegetation traits expected in coming years,” he said. “These observations will help advance models to incorporate ecosystem processes, climate and CO2 feedbacks more realistically.” The results of the study also highlight the importance of the role of ecosystems in the global carbon cycle. According to Poulter, going forward, the decreasing carbon-uptake efficiency of land ecosystems means we may see the amount of CO2 remaining in the atmosphere after fossil fuel burning and deforestation start to increase, shrinking the remaining carbon budget. “What this means is that to avoid 1.5 or 2 °C warming and the associated climate impacts, we need to adjust the remaining carbon budget to account for the weakening of the plant CO2 Fertilization Effect,” he said. “And because of this weakening, land ecosystems will not be as reliable for climate mitigation in the coming decades.”
  • NASA Finds What a Glacier's Slope Reveals About Greenland Ice Sheet Thinning
    As glaciers flow outward from the Greenland Ice Sheet, what lies beneath them offers clues to their role in future ice thinning and sea-level rise contribution. Outlet glaciers are rivers of ice flowing within the cracks of the bedrock and draining into the surrounding sea. They retreat and start to thin as climate warms, and this thinning works its way toward the center of the ice sheet. Now, by looking at the bed topography beneath the ice, scientists have a better understanding of which glaciers could have a significant impact on the Greenland Ice Sheet’s contribution to sea-level rise in coming years. They found that some glaciers flowing over gentler slopes could have a greater impact than previously thought. The gentle slopes allow thinning to spread from the edge of the ice sheet far into the interior, whereas glaciers with steep drops in their bed topographies limit how far into the interior thinning can spread. The research, which was published December 11th in Geophysical Research Letters, analyzed 141 outlet glaciers on the Greenland Ice Sheet to predict how far into the interior thinning may spread along their flow lines, starting from the ocean edge. “What we discovered is some glaciers flow over these steep drops in the bed, and some don’t,” said lead author Denis Felikson with NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the Universities Space Research Association (USRA). “For the glaciers that do have that steep drop in the bed, thinning can’t make its way past those drops.” Borrowing a term from geomorphology – the study of Earth’s physical features – they coined these steep drop features “knickpoints.” When a river flows over a knickpoint, it often results in a waterfall or a lake. But for glaciers, steep is a relative term which in reality translates to just about three degrees of incline. “It’s not like the ice is going over a cliff,” said Felikson. “But in terms of glacier dynamics, they are very steep – an order of magnitude more steep than a typical bed that the ice flows over.” The researchers were able to identify these “steep” changes in topography using digital elevation models of the ice sheet bed and surface topography. Surface topography came from the Greenland Ice Mapping Project, created using NASA’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument that flies aboard NASA’s Terra satellite, in conjunction with data from NASA’s Ice, Cloud, and land Elevation Satellite (ICESat) mission. The bed topography digital elevation model, known as the BedMachine data set, is a high-resolution model of the bed beneath the Greenland Ice Sheet, created using data from NASA’s Operation IceBridge airborne surveys of polar ice. “This bed topography data set was critical to us doing our work,” Felikson said. “And it is thanks to NASA remote sensing, namely the Operation IceBridge surveys, that we were able to do this.” Using the remote sensing data, scientists were able to compare topography measures to produce a single metric along a glacier’s flow line. This helped them identify a break point between the upstream and downstream parts of the glacial ice. Ice below the knickpoint is susceptible to thinning from the glacier’s edge. But the thinning does not extend beyond this point upstream, so the interior of the ice sheet is not impacted. Of all the glaciers observed, a majority (65%) had discernable knickpoints. Especially steep knickpoints are prevalent in the more mountainous regions of Greenland, where several of the biggest and fastest moving glaciers also show knickpoints that are relatively close to the coast. By sheer size alone these glaciers could contribute significantly to ice sheet thinning and melt, but because their knickpoints are near the coast, thinning is not expected to spread far inland. GIF showing the potential distances over which thinning can spread into Greenland’s interior. Glaciers in regions of higher elevation, tend to pervade less inland than those in regions of lower elevation. Credit: Denis Felikson However, glaciers that flow through gentle topography are found to either have gradual knickpoints, or no knickpoint at all. Such glaciers are of interest, and concern, because even those that are smaller in size have the potential to let thinning expand hundreds of kilometers inland, eroding the heart of the ice sheet. “They could be impactful in terms of sea level rise, not because they are big and deep, but because they have access to more ice that they can eat away,” said Felikson. “It will take them a lot longer to respond, but over the long term they could end up contributing just as much to sea level rise, maybe, as the big glaciers.” Over the gentle topography of the northwest coast of Greenland, nine of twelve neighboring glaciers are predicted to thin more than 250 km (155.3 miles) into the interior of the ice sheet, over a ∼140-km (86.9 mile) wide region. The northwest sector of the ice sheet is also the only region experiencing an ongoing increase in ice discharge over the last couple decades, and Felikson predicts that it will continue to do so given the characteristics of these glaciers. This work was started at the University of Texas as part of Felikson’s dissertation and has continued throughout his time at NASA Goddard. The origins of knickpoints and their implications for long-term thinning, as well as Greenland’s overall contribution to sea level rise, remain the basis for future research. The data used in this study is available at https://zenodo.org/record/4284759.
  • Water Limitations in the Tropics Offset Carbon Uptake from Arctic Greening
    More plants and longer growing seasons in the northern latitudes have converted parts of Alaska, Canada and Siberia to deeper shades of green. Some studies translate this Arctic greening to a greater global carbon uptake. But new research shows that as Earth’s climate changes, increased carbon absorption by plants in the Arctic is being offset by a corresponding decline in the tropics. "This is a new look at where we can expect carbon uptake to go in the future,” said scientist Rolf Reichle with the Global Modeling and Assimilation Office (GMAO) at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Reichle is one of the authors of a study, published Dec. 17 in AGU Advances, which combines satellite observations over 35 years from the National Oceanic and Atmospheric Administration (NOAA’s) Advanced Very High Resolution Radiometer (AVHRR) with computer models, including water limitation data from NASA’s Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2). Together, these provide a more accurate estimate of global "primary productivity" – a measure of how well plants convert carbon dioxide and sunlight to energy and oxygen via photosynthesis, for the time span between 1982 to 2016. Arctic Gains and Tropical Losses Plant productivity in the frigid Arctic landscape is limited by the lengthy periods of cold. As temperatures warm, the plants in these regions have been able to grow more densely and extend their growing season, leading to an overall increase in photosynthetic activity, and subsequently greater carbon absorption in the region over the 35-year time span. However, buildup of atmospheric carbon concentrations has had several other rippling effects. Notably, as carbon has increased, global temperatures have risen, and the atmosphere in the tropics (where plant productivity is limited by the availability of water) has become drier. Recent increases in drought and tree mortality in the Amazon rainforest are one example of this, and productivity and carbon absorption over land near the equator have gone down over the same time period as Arctic greening has occurred, canceling out any net effect on global productivity. A map of the world shows the changes in global gross primary productivity (GPP), an indicator of carbon uptake, from 1982–2016. Each dot indicates a region with a statistically significant trend. Credit: NASA/Nima Madani Adding Satellites to Productivity Models Previous model estimates suggested that the increasing productivity of plants in the Arctic could partially compensate for human activities which release atmospheric carbon, like the burning of fossil fuels. But these estimates relied on models that calculate plant productivity based on the assumption that they photosynthesize (convert carbon and light) at a given efficiency rate. In reality, many factors can affect plants’ productivity. Including satellite records like those from AVHRR provide scientists with consistent measurments of the global photosynthetic plant cover, and can help account for variable events such as pest outbreaks and deforestation that previous models do not capture. These can impact the global vegetation cover and productivity. “There have been other studies that focused on plant productivity at global scales,” said Nima Madani from NASA’s Jet Propulsion Laboratory, (JPL) Pasadena, California, and lead author of the study, which also includes scientists from the University of Montana. “But we used an improved remote sensing model to have a better insight into changes in ecosystem productivity.” This model uses an enhanced light use efficiency algorithm, which combines multiple satellites’ observations of photosynthetic plant cover and variables such as surface meteorology. “The satellite observations are critical especially in regions where our field observations are limited, and that’s the beauty of the satellites,” Madani said. “That’s why we are trying to use satellite remote sensing data as much as possible in our work.” It was only recently that the satellite records began to show these emerging trends in shifting productivity. According to Reichle, “The modelling and the observations together, what we call data assimilation, is what really is needed.” The satellite observations train the models, while the models can help depict Earth system connections such as the opposing productivity trends observed in the Arctic and tropics. Brown Is the New Green The satellite data also revealed that water limitations and decline in productivity are not confined to the tropics. Recent observations show that the Arctic’s greening trend is weakening, with some regions already experiencing browning. “I don’t expect that we have to wait another 35 years to see water limitations becoming a factor in the Arctic as well,” said Reichle. We can expect that the increasing air temperatures will reduce the carbon uptake capacity in the Arctic and boreal biomes in the future. Madani says Arctic boreal zones in the high latitudes that once contained ecosystems constrained by temperature are now evolving into zones limited by water availability like the tropics. These ongoing shifts in productivity patterns across the globe could affect numerous plants and animals, altering entire ecosystems. That can impact food sources and habitats for various species, including endangered wildlife, and human populations. The data produced from this study are publicly accessible at https://doi.org/10.3334/ORNLDAAC/1789.
  • Seeing the COVID-19 Pandemic from Space
    Economic and social shutdowns in response to the COVID-19 pandemic have led to noticeable changes in Earth’s environment, at least for the short term. NASA researchers are using satellite and ground-based observations to track these impacts on our air, land, water, and climate. These datasets have been collected in a free and openly available online dashboard. // I added jquery on ready here to fix bug that was preventing // the module from expanding beyond height:0 -JM $(function() { // load curtain modules within hidden sections when expand link is clicked $(".curtain_container:hidden").parents(".expandable_element").siblings(".expandable_element_link").on("click.curtain", function(){ $(this).siblings(".expandable_element").find(".curtain_container").twentytwenty(); $(this).off("click.curtain"); }); $(".curtain_container").imagesLoaded(function(){ $(".curtain_container").twentytwenty(); }); }); Nitrogen Dioxide Levels Over San Francisco, California Nitrogen dioxide (NO2), an air pollutant, decreased significantly over urban areas during the pandemic. The left image above shows average NO2 levels over San Francisco for the past 5 years, and the right image shows NO2 levels over San Francisco in March 2020. These data are from NASA's Ozone Monitoring Instrument (OMI). Credit: NASA COVID-19 Dashboard The NASA COVID-19 Dashboard features data collected by Earth-observing satellites, instruments aboard the International Space Station, and sensitive ground-based networks. The global maps are searchable by several categories of observable change, including economic indicators, such as shipping and construction activity, and environmental factors, such as water quality and climate variations. Investigate the data layers yourself or take a guided tour of how NASA Earth scientists are studying – and learning about – the pandemic’s effects on the Earth system. NASA scientists use many different tools, datasets, and methods to investigate COVID-related changes in the Earth system. Comparing complementary datasets on the dashboard helps reveal a deeper story of how the environment is changing due to COVID-related shutdowns. Thermal data from the joint NASA-U.S. Geological Survey Landsat satellite show decreases in the urban heat island effect, a phenomenon where urban areas are significantly warmer than adjacent rural areas, during the pandemic. The left image shows temperatures over San Francisco in April 2018, while the right image shows temperatures over San Francisco in April 2020. Scientists found that large parking lots, highway corridors, and commercial rooftops were on average 10-15 degrees Fahrenheit (5-8 degrees Celsius) cooler from March to May 2020, compared to previous years. Credit: NASA COVID-19 Dashboard. For example, scientists at NASA’s Ames Research Center discovered that emptier parking lots near closed, non-essential businesses, in combination with cleaner air from less surface transportation, meant that heat from the sun radiating off dark asphalt and cement surfaces did not stay trapped near the ground as long. Instead, heat dissipated quickly, cooling the urban environment. Comparing the data to pre-pandemic years, scientists found that large parking lots, highway corridors, and commercial rooftops were, on average, 10-15 degrees Fahrenheit (about 5-8 degrees Celsius) cooler from March to May 2020. The NASA COVID-19 Dashboard will be updated with more data and discoveries throughout the pandemic and beyond.
  • Sea Level Projections Drive San Francisco's Adaptation Planning
    As a utilities planner for the City and County of San Francisco, David Behar knows that access to the latest information about sea level rise is crucial to his job -- and his city. Behar is climate program director for the San Francisco Public Utilities Commission. He tracks the latest climate science and leads the translation of that work for the agency and other city departments, working with a team of engineers and planners. His work includes assessing the vulnerability of the city’s water supply, a role for which his expertise as the founding chair for the Water Utility Climate Alliance has prepared him well. The Alliance provides leadership and collaboration on climate change issues to water agencies that supply drinking water to more than 50 million Americans throughout the United States. “My focus is on adaptation planning,” Behar said. “What is it we need to do to be ready for the effects of climate change? What uncertainties do we face?” Get NASA's Climate Change News: Subscribe to the Newsletter » To understand and plan for current and future threats from sea level rise, the San Francisco Public Utilities Commission has traditionally relied heavily on global observations and projections from the Intergovernmental Panel on Climate Change (IPCC), the National Research Council (NRC), and the State of California. Because scientific projections typically have uncertainties that complicate decision making, Behar says he’s always interested in new research that helps them understand the short- to medium-term challenges they face. One area of research that’s caught his attention of late is the work Ben Hamlington and his team at NASA’s Jet Propulsion Laboratory in Southern California are conducting to understand the impact of ongoing changes in a natural ocean climate cycle called the Pacific Decadal Oscillation (PDO), a key driver of sea level fluctuations along the West Coast. The PDO alternates between warm and cool phases about every five to 20 years, bringing warm or cool waters to the West Coast and raising or lowering sea levels in the process. Understanding these natural sea level variations is important, as they can lead to extended periods of elevated flood risk that compound the impacts of long-term global sea level rise due to global warming. Hamlington’s research shows that a shift in the PDO from a cool to a warm phase in the past decade has led to increasing sea level along the West Coast. Scientists have seen an increase of about 0.4 inches (10 millimeters) a year for the past five years. Based on comparisons to available past observations from tide gauges and satellite altimetry, they project the West Coast will continue to see similar increases for the next few years. Members of the San Francisco Public Utilities Commission consult with scientists to plan for climate change at a Climate Information Workshop in March 2019. Credit: San Francisco Public Utilities Commission Behar says the change in the PDO and its impact on sea level rise will garner a lot of attention among West Coast sea level rise planners because it provides a preview of longer-term, more permanent trends. “There’s not a single planner I know who’s actively using the term 'PDO' in their daily work,” Behar said. “I want our decision makers to know in advance what this trend will look like for our shorelines. From what I’ve seen, nobody is talking about 0.4 inches a year of sea level rise on the West Coast yet. We’ll need to accelerate our short- and medium-term planning a little bit.” Behar says most efforts by planners to adapt to sea level rise employ a step-by-step approach that allows them to be resilient not just to changes taking place today, but also to what they think they’ll see in the next 20 to 30 years, as well as longer-term, more dangerous trends. This approach helps them handle uncertainty. Because of this step-by-step process, Behar says it’s valuable to know what’s happening today on the ground and in the water. “It gives us clues about the short- to medium-term challenges we face,” he said. Now that the San Francisco Public Utilities Commission is starting to understand San Francisco’s potential vulnerabilities to sea level rise, Behar says they’re planning adaptation measures. “We need to start thinking about investing in adaptation,” he said. “What’s happening today and over the next 10 years can be as important as projections (of sea level rise) on a century scale. But we see a lot more reporting about long-term projections than we do about observations.” Behar says research on the PDO can give the San Francisco Public Utilities Commission an understanding of short-term challenges that can inform their long-term planning. For example, their adaptation playbook includes investments in green infrastructure, such as establishing wetlands to reduce the effects of wave action. The life cycle of this green infrastructure solution depends almost entirely on the pace of short-term sea level rise. So, this information about the PDO is important for understanding how to design infrastructure for sea level rise solutions. “This new research on the PDO tells us that instead of 2.6 inches (66 millimeters) of sea level rise, we might see 4 inches (100 millimeters) over a decade and 8 inches (200 millimeters) over 20 years, which matches what we’ve seen over the previous century,” he said. “That will be noticeable. This acceleration of sea level rise will be felt most strongly by shorelines that today are at or near the mean high tide line.” Behar says accelerated sea level rise will lead to more frequent flooding, first during king tides but then during regular high tides. King tides, which are associated with the position of the Sun and Moon and are unrelated to climate change, bring an additional 8 to 12 inches (200 to 300 millimeters) of water to coastlines. “Some shorelines in South San Francisco Bay are low gradient (gently sloping) and will flood easily,” he said. “It will also create some vulnerability in the short term because a lot of places are sensitive to 4 inches of sea level rise. In addition to the PDO and El Niño, we’ve got king tides and storm surges, all of which will raise water levels and create a greater urgency for adaptation action. “It’s really important that this information be made available to people in local governments who are in charge of planning sea level adaptation response and that it be made understandable for them through collaboration with the academic community,” he added. Further reading: Changing Pacific Conditions Raise Sea Level Along U.S. West Coast New High Tide Flooding Projection Tool Aids U.S. Coastal Decision Making
  • NASA, US, European Partner Satellite Returns First Sea Level Measurements
    Sentinel-6 Michael Freilich, a joint U.S.-European satellite built to measure global sea surface height, has sent back its first measurements of sea level. The data provide information on sea surface height, wave height, and wind speed off the southern tip of Africa. "We're excited for Sentinel-6 Michael Freilich to begin its critical work studying sea level and helping us understand the many aspects of our planet's global ocean," said Thomas Zurbuchen, NASA's associate administrator for science at the agency's headquarters in Washington. "I know Mike would be thrilled that the satellite bearing his name has begun operating, but he'd also be looking forward to studying the data from this important mission, as we all are." Since the successful Nov. 21 launch from Vandenberg Air Force Base in California aboard a Space-X Falcon 9 rocket, engineers and scientists have spent several weeks switching on and checking out the satellite and its instruments, making sure everything is operating as it should. Get NASA's Climate Change News: Subscribe to the Newsletter » "Christmas came early this year," said Josh Willis, project scientist at NASA's Jet Propulsion Laboratory in Southern California. "And right out of the box, the data look fantastic." Sentinel-6 Michael Freilich will continue a decades-long effort to measure global ocean height from space, which started in the early 1990s. Since then, the rate of sea level rise has doubled with a current rate of 0.16 inches (4 millimeters) per year. The rise is caused almost entirely by a combination of meltwater from land-based glaciers and ice sheets and the fact that seawater expands as it warms. This graphic shows radar measurements, called waveforms, collected by the sea level instrument on Sentinel-6 Michael Freilich. The waveform provides data on sea level, wave height, and wind speed. The high-resolution waveform provides data on smaller ocean features like coastal currents. Credit: EUMETSAT and CNES "Data from Sentinel-6 Michael Freilich will help us evaluate how the Earth is changing," said Karen St. Germain, director of NASA's Earth Science Division. "When we combine the data from instruments like the altimeter on Sentinel-6 Michael Freilich with data from other satellites like GRACE-FO and IceSat-2, we can tell how much of the sea level rise is due to melting ice and how much is due to expansion as the oceans warm. Understanding these underlying physical mechanisms is what allows NASA to improve projections of future sea level rise.” The initial orbit for Sentinel-6 Michael Freilich was 11.4 miles (18.4 kilometers) lower than its ultimate operational orbit of 830 miles (1,336 kilometers) above Earth. Engineers plan to move the satellite into its operational orbit by mid-December, where it will trail the Jason-3 satellite by 30 seconds. During this tandem flight, scientists and engineers will spend the next six to 12 months cross calibrating the data collected by both satellites to ensure the continuity of measurements between the two. Once assured of the data quality, Sentinel-6 Michael Freilich will then become the primary sea level satellite. The first publicly available sea level data will be available in about six months, with the rest available within a year. "We are now gearing up the operational systems supporting the processing of the instruments' data by EUMETSAT and partner organizations, as they are all contributing to this complex process,” said Manfred Lugert, program manager for the Sentinel-6/Jason-CS (Continuity of Service) mission at the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) “This will keep us busy for the next few months, as the independent scientific validation and fine tuning need to be undertaken very carefully." Lugert expects the first operational products from the mission would be available to those who need them by mid-2021. In addition to measuring sea level, Sentinel-6 Michael Freilich is monitoring atmospheric temperature and humidity, which will help improve weather and hurricane forecasts. Engineers and scientists turned on that instrument Nov. 27, and the initial data look good. More About the Mission Sentinel-6 Michael Freilich is named in honor of the former director of NASA's Earth Science Division, who was a leading figure in advancing ocean observations from space. Freilich passed away Aug. 5, 2020. "I think he would be proud," said Willis. "Like Mike himself, we expect great things from the satellite that bears his name, and so far, it's looking good." The spacecraft is one of two identical satellites that will extend a nearly 30-year sea level record collected by an ongoing collaboration of U.S. and European satellites by another decade. That record began in 1992 with the TOPEX/Poseidon satellite and continued with Jason-1 (2001), OSTM/Jason-2 (2008), and Jason-3, which has been observing Earth's oceans since 2016. Sentinel-6 Michael Freilich will pass the baton to its twin, Sentinel-6B, in 2025. Both spacecraft are a part of the Sentinel-6/Jason-CS mission, which will collect accurate measurements of sea surface height for more than 90% of the world's oceans. The satellites will also monitor atmospheric temperature and humidity, as well as wave height and wind speed, which will provide crucial information for operational oceanography, marine meteorology, and climate studies. ESA (European Space Agency), EUMETSAT, NASA, and the National Oceanic and Atmospheric Administration (NOAA) are jointly developing the Sentinel-6/Jason-CS mission, with funding support from the European Commission and support from France's National Centre for Space Studies (CNES). The mission is part of Copernicus, the European Union's Earth observation program, which the European Commission manages. NASA's contributions to the Sentinel-6/Jason-CS mission are three science instruments for each of the two satellites: the Advanced Microwave Radiometer for Climate, the Global Navigation Satellite System - Radio Occultation, and the Laser Retroreflector Array. NASA also contributed launch services, ground systems supporting operation of the NASA science instruments, the science data processors for two of these instruments, and support for the U.S. members of the international Ocean Surface Topography Science Team. NASA’s Jet Propulsion Laboratory at the California Institute of Technology in Pasadena manages the agency’s contribution to the mission. For more information, visit: https://www.nasa.gov/sentinel-6 https://www.esa.int/Sentinel-6 https://edefis.eu/CopernicusFactsheets News Media Contacts Grey Hautaluoma / Tylar Greene Headquarters, Washington 202-358-0668 / 202-358-0030 grey.hautaluoma-1@nasa.gov / tylar.j.greene@nasa.gov Jane J. Lee / Ian J. O'Neill Jet Propulsion Laboratory, Pasadena, Calif. 818-354-0307 / 818-354-2649 jane.j.lee@jpl.nasa.gov / ian.j.oneill@jpl.nasa.gov
  • Beyond Ice: NASA's ICESat-2 Shows Hidden Talents
    For a satellite with ice in its name, and measuring ice as its mission, NASA’s ICESat-2 is also getting a lot of attention from scientists who have warmer subjects in mind. At this month’s Fall Meeting of the American Geophysical Union (AGU), researchers are highlighting how the Ice, Cloud and land Elevation Satellite 2 is helping to understand aspects of our home planet far beyond what it was intended to do. When ICESat-2 sent back its first measurements on the heights of Earth’s surface in early 2019 the ICESat-2 science team lead, Lori Magruder of the University of Texas, recalls her colleague and fellow science team member Amy Neuenschwander banging on their shared office wall for her to come look at one of the first data sets: A profile of the Mexico coastline showed mountains and trees as expected, but then also continued to the ocean, where both waves at the surface as well as the seafloor below were easily distinguishable. Around the same time, Helen Fricker of Scripps Institution of Oceanography zeroed in on her favorite swath of Antarctic ice – the Amery Ice Shelf – not to look at the height of the frozen ice itself, but to see if meltwater pooling on the surface of the ice shelf was visible from space (it was). “It’s amazing what you can see with this data, and it just keeps sparking people's curiosity,” Magruder said. Get NASA's Climate Change News: Subscribe to the Newsletter » ICESat-2's main science objective is ice, but the mission is also able to measure the heights of other features, including ocean bathymetry, trees and mountain glaciers. Credit: NASA's Goddard Space Flight Center Before its September 2018 launch, the ICESat-2 mission team was focused on making sure the satellite met its science requirements, said Tom Neumann, the mission’s project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. And it has, by precisely measuring the height of the ice sheets at Earth’s poles, of sea ice floes above the ocean waters, and of forest canopies. The satellite’s continuous coverage around the globe, with height measurements of Earth’s surface taken every 2.3 feet (70 centimeters) along its ground path, has made ICESat-2 datasets appealing to those studying rivers, coastal regions, forests and more, he said. “After two years, we have a lot of data over a lot of places, including some latitudes where other satellites don’t cover,” Neumann said. “This gives researchers a wealth of information to use in any number of creative ways.” Water on Ice During the Antarctic summer, networks of rivers and ponds appear on some ice shelves and glaciers at the edge of the continent. To estimate how much ice has melted and how much water has filled these ponds, scientists generally turn to satellite images. They infer depth based on the color of the ponds – darker blue means deeper water, Fricker said. ICESat-2’s laser instrument, however, can directly measure both the height of the top of the melt pond and of the ice below. Fricker and her colleagues compared the results using ICESat-2 data with results from just images. In a new study presented at the AGU meeting, they found that the imagery-only methods underestimated the depth of the melt ponds by 30% to 70%. Now, the team is working on ways to incorporate the new depth data with the imagery data. “The strength is in combining the two,” she said. Researchers are also using ICESat-2 to investigate the meltwater that pools on floes of Arctic sea ice – which impact how much heat from the Sun is absorbed by the planet. These ponds can be as big as Olympic-sized swimming pools, or bigger, and about 2.5 feet (80 cm) deep. Traditionally, the size of these melt ponds has been estimated based on relationships between area and depth from fieldwork done in 1998, said Sinead Farrell, an ice scientist at the University of Maryland, College Park “A lot has changed in the Arctic since then – we’ve lost a lot of the thicker, older ice, and so we want to see if those observations made in the ‘90s are still representative today,” Farrell said. With the precise measurements of ICESat-2, which show ridges, cracks and ponds on the sea ice, scientists can research that question and others. One of Farrell’s graduate students, Ellen Buckley, also of the University of Maryland, is presenting work at the AGU meeting that describes ways to automatically detect melt ponds on sea ice in the ICESat-2 datasets, and track how they change throughout the summer season. This information could be used to help improve the sea ice forecasts used by ships navigating the Arctic. Water on Land In the mountainous regions of Asia, it can be difficult to measure how much water is flowing down rivers, but it’s key for forecasting water availability as well as flood potential. Heidi Ranndal, a scientist with the Technical University of Denmark in Copenhagen, is using ICESat-2 to improve the measurements that she gets with radar satellites. She’s able to acquire thousands of useful height measurements of a river like the Yangtze from ICESat-2. “I was looking at an ICESat-2 track crossing the Yangtze River, and I could actually see the outline of a ship,” Ranndal said. “That was very impressive, since usually I would get just a few data points, which makes it harder to determine the height.” Radar satellite data, like that from the European Space Agency's CryoSat-2 or Sentinel-3, has its strengths though – those satellites measure a given area more frequently than ICESat-2 does, and also take measurements through clouds, which ICESat-2 cannot do. So she’s combining the two types of data to improve river flow estimates, and presenting the results at the AGU meeting. Land under Water With ICESat-2’s ability to measure both the surface of water and the seafloor below it – up to 140 feet (43 meters) in optimal conditions – researchers are also using the satellite to investigate coastal ecosystems. The bathymetry of the seafloor is generally well-characterized at a global scale, but there’s a gap in knowledge about the shallow waters between the coastline and the open ocean where existing data does not contain enough detail, said Nathan Thomas, a scientist at NASA Goddard. It can be cost-prohibitive, or even dangerous, to measure these areas by ship, so he is working to combine ICESat-2 measurements with existing satellite datasets to better map coral reefs, sea grasses, tidal flats and other aquatic ecosystems. Thomas is also using ICESat-2 to measure mangrove forests from the tops of the trees, to the base of their roots – a tricky task given that the roots are sometimes submerged under water. If he and his colleagues can measure the full height of these trees, however, while compensating for the tides, they can calculate the stores of biomass and carbon held in these forests, and add those to the global ICESat-2 biomass inventory. Focusing on that same gap between land and open oceans, Brett Buzzanga of Old Dominion University in Norfolk, Virginia, is investigating how well ICESat-2 can measure sea level rise in coastal regions. “ICESat-2 can detect sea level changes at a high spatial resolution, and so can measure these coastal regions – it really complements other satellites and methods we use to measure sea level rise,” he said. He’s also presenting data at AGU that shows what appears to be a tsunami that ICESat-2 passed over at just the right time. But he’s mostly interested in the small features of the ocean processes that are hard to measure with other remote sensing tools. Magruder is presenting research at the AGU meeting that examines how to use ICESat-2 to improve nearshore bathymetry maps – and said she’s excited to see what other uses people come up with for the satellite’s data. “It’s almost like a snowball effect, with someone saying if they can map mangroves, maybe I can do coral reefs, or maybe even ocean phytoplankton,” she said. “It’s been really fun, and everyone’s so energetic about the data and the mission.”
  • New High Tide Flooding Projection Tool Aids U.S. Coastal Decision Making
    A new tool developed with funding from NASA’s Earth Science Division helps decision makers and others assess how sea level rise and other factors will affect the frequency of high tide flooding in U.S. coastal locations in the next 50 to 100 years. High-tide flooding, also known as “sunny day” or nuisance flooding, is an increasingly frequent occurrence in coastal areas around the United States. The Flooding Days Projection Tool is an online dashboard that projects the number of high tide flooding days per year for 97 U.S. cities, based on National Oceanic and Atmospheric Administration (NOAA) impact thresholds. These thresholds provide a safety gap between regular high tide water levels and conditions that result in flooding. Coastal communities are built a certain elevation above sea level with these natural fluctuations in mind. The tool is based on projections of sea level rise and the height of the highest astronomical tides, which vary on a predictable 18.6-year cycle that’s determined by the Moon’s orbit around Earth. Over multiple decades, changes in the Moon’s orbit cause cyclical variations in the height of high and low tides in certain regions. These changes occur slowly. Get NASA's Climate Change News: Subscribe to the Newsletter » This graph from the Flooding Days Projection Tool developed by the University of Hawaii Sea Level Center depicts projections of the number of minor flooding days in Los Angeles under various sea level rise scenarios for the 21st century. A minor flooding day is defined as a day for which the highest water level exceeds NOAA's minor flooding threshold, which for Los Angeles is 57 centimeters (22.4 inches) above the average daily maximum tide. The inflection in the 2030s and subsequent rapid increase are related to the interaction between sea level rise and predictable cycles in the height of high tides that span multiple decades. Credit: University of Hawaii Sea Level Center “Tides aren’t as constant as people think they are,” said Phil Thompson, director of the University of Hawaii’s Sea Level Center in Honolulu and an assistant professor in the university’s Department of Oceanography, who developed the tool. “They change on long time scales.” When high tides get lower, the net effect of sea level rise on flooding is reduced. The tool predicts this will happen in many U.S. locations from the mid-2020s until the mid-2030s, when high tides will once again get higher. When increases in high tides synch up with increases in global or regional sea level rise and other factors that cause sea levels to vary, there’s a potential for rapid increases in coastal water levels and associated impacts. For regions where the rate of sea level rise is already accelerating, such as along the U.S. West Coast, the cycle will exacerbate those impacts. “We’ll observe a rapid increase in high tide flooding days for regions around the globe,” Thompson said. “For a place like California, the height of high tides will increase 3 to 5 centimeters over 10 years, on top of a similar increase from sea level rise that’s driven by climate change.” Thompson says this will result in numerous changes. For example, assuming NOAA’s intermediate sea level rise scenario, beginning in the mid-2030s, the frequency of high tide flooding events each year in the Los Angeles coastal area will go from fewer than 10 to more like 40. In San Diego, annual flooding events will increase from 15 to more than 60. And in San Francisco, they’ll go from fewer than 10 to almost 40 per year. “The last time this lunar cycle increased high tides, we couldn’t see the impacts because sea level rise hadn’t pushed these events over the flooding threshold yet,” said Thompson. “But next time we will, because sea level rise is ongoing.” Further reading: Changing Pacific Conditions Raise Sea Level Along U.S. West Coast Sea Level Projections Drive San Francisco's Adaptation Planning Beating Back the Tides
  • Noise and Light Pollution From Humans Alter Bird Reproduction
    Human-produced noise and light pollution are troublesome to our avian neighbors, according to new research from a team at California Polytechnic State University, published November 11 in Nature. Using NASA satellite data, the researchers got a bird’s-eye view of how noise and light negatively affected bird reproduction in North America. The team also discovered that these factors might interact with or even mask birds’ responses to the effects of climate change. Bird populations have declined by about 30 percent in the last few decades. Scientists and land managers seeking to understand what caused the decline and reverse the trend had largely overlooked the effects of noise and light pollution, until recent studies suggested that these stressors could harm certain types of birds. Get NASA's Climate Change News: Subscribe to the Newsletter » Prior to the launch of the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard the joint NASA-National Oceanic and Atmospheric Association (NOAA) Suomi National Polar-orbiting Partnership (NPP) satellite in 2011, high resolution light pollution data didn’t exist on such a large scale. This new study has produced a continent-wide picture utilizing VIIRS data. The study focused on 142 North American bird species, including the ash-throated flycatcher shown above. Credit: David Keeling/California Polytechnic State University “Our study provides comprehensive evidence that noise and light can profoundly alter reproduction of birds, even when accounting for other aspects of human activities,” said Clint Francis, a biologist at California Polytechnic State University, San Luis Obispo, California, one of the lead authors on the study. The research team looked at a vast collection of data sets – including those collected by citizen scientists through the NestWatch Program – to assess how light and noise affected the reproductive success of 58,506 nests from 142 bird species across North America. They considered several factors for each nest, including the time of year when breeding occurred and whether at least one chick fledged – or flew – from the nest. Birds’ reproduction coincides with peak food availability to feed their young, as daylight cues signal to breed around the same time each year. The researchers found that light pollution causes birds to begin nesting as much as a month earlier than normal in open environments, such as grasslands or wetlands, and 18 days earlier in forested environments. The consequence could be a mismatch in timing – for example, hungry chicks may hatch before their food is readily available. If that happens, these early season nests may be less successful at fledging at least one chick, but the situation is complicated by climate change. As the planet warms, birds’ food is available earlier due to warmer weather. Birds that maintain their historical breeding times because their internal clocks are set to changes in daylength may have fewer chicks survive because the food source they rely on already came and went. “We discovered that the birds that advanced the timing of their reproduction in response to increased light pollution actually have better reproductive success,” Francis said. “A likely interpretation of this response is that light pollution actually allows these birds to ‘catch up’ to the shift towards earlier availability of food due to climate change.” These findings suggest two conclusions about birds’ responses to climate change. First, at least temporarily, birds in lit conditions may be tracking climate change better than those in dark areas. Second, when scientists thought birds were adjusting their reproductive timing to climate change, birds may have actually been instead responding to light cues since many studies were done in areas exposed to some light pollution. Many areas of the United States are significantly brighter at night due to human-produced light pollution. This map – constructed with VIIRS data – shows areas with increased light pollution (yellow and pink) compared to the typical brightness of the night sky (darker blues). Credit: Francis et al. When considering noise pollution, results showed that birds that live in forested environments tend to be more sensitive to noise than birds in open environments. Researchers delved into greater detail in 27 different bird species, looking for physical traits that could explain the variations in species’ responses to light and noise. A bird’s ability to see in low light and the pitch of its call were related to species’ responses to light and noise pollution. The more light a bird’s eye is capable of taking in, the more that species moved its breeding time earlier in the year in response to light pollution, and the more that species benefited from light pollution with improved nest success. Noise pollution delayed nesting for birds’ whose songs are at a lower frequency and thus more difficult to hear through low-frequency human noise. Mating decisions are made based on the male’s song, and in some cases, females need to hear the male’s song to become physically ready to breed. These trait and environment-specific results have strong implications for managing wild lands. Developers and land managers could use this study to understand how their plans are likely to affect birds. For example, Francis says, “Is it a forest bird? If so, it is likely that it is more sensitive to light and noise.” The study is the first step toward a larger goal of developing a sensitivity index for all North American birds. The index would allow managers and conservationists to cross-reference multiple physical traits for one species to assess how factors such as light and noise pollution would affect each species.
  • Arctic Animals' Movement Patterns are Shifting in Different Ways as the Climate Changes
    For animals in the Arctic, life is a balancing act. Seasonal cues, such as warmer spring temperatures or cooler temperatures in the fall, tell animals when to migrate, when to mate, and when and where to find food. Predators and prey, birds and mammals alike follow this natural schedule, and an overall shift of just a few days or weeks could have unknown impacts on these animals and ecosystems. These changes in seasonal timing are already starting – although the shifts differ between species and populations – according to a new study published Nov. 5 in Science that was funded in part by the NASA Arctic-Boreal Vulnerability Experiment (ABoVE). The researchers analyzed data from the Arctic Animal Movement Archive (AAMA), a collection of data from more than 200 research studies tracking nearly a hundred species from 1991 to present, in combination with NASA temperature, rainfall, snowfall, and topographic data. They found that Arctic animals’ movement patterns are shifting in different ways, which could disrupt entire ecosystems. “The Arctic is showing more extreme indications of climate change,” said Gil Bohrer, a professor and environmental engineer at Ohio State University in Columbus. Sea ice is shrinking, rainfall, and snowfall are changing, and Arctic tundra is turning green in some places and brown in others. “Arctic animals are responding to these changes, they’re responding quickly, and that response is not equal,” said Bohrer. Get NASA's Climate Change News: Subscribe to the Newsletter » This timelapse shows the movement patterns for various animals (colors indicate different animal types) over the course of a year. Animal migration in the Arctic is highly seasonal, as various species and populations move around in search of food, suitable temperatures, and places to mate and raise their young. The team focused on three examples: a long-term study of eagle migrations, a massive study on caribou populations, and a multi-species study focusing on several predator and prey species. In the eagle study, the researchers analyzed when eagles left their wintering grounds to fly north for the summer, based on National Oceanic and Atmospheric Administration (NOAA) data collected from 1991 to 2019. On average, migration started about half a day earlier each year – a change that compounded over 25 years to cause a shift of nearly two weeks. “Basically, climate change is rushing them to go north early,” said Bohrer. The shift was more pronounced for adult eagles than juveniles, suggesting that the juveniles may be missing out on the mating season or the adults may be reaching their summering grounds before their food sources. Researchers release several eagles after affixing tags to track the eagles’ movement. Credit: Bryan Bedrosian / Teton Raptor Center However, the researchers don’t know whether these changes will benefit or harm different animal species, populations, or individuals. For example, in the caribou study, it appeared that certain caribou populations were adapting to the changes in their surroundings. Bohrer says that we’ll likely see some species, individuals, and populations benefitting from climate change and others harmed by climate change. “But that fact that we see changes is showing that something big is going on,” explained Bohrer. This is the first indication of caribou populations showing an adaptive response to climate change. Credit: Kyle Joly / National Park Service Typically, caribou mate in the fall, are pregnant in the winter, and raise their young in the spring when food is abundant; this schedule is tightly coordinated with environmental patterns. The team analyzed five caribou populations and found that populations living in the northern Arctic – where things are shifting more rapidly due to climate change – were having offspring earlier to coincide with the changes in their environment, suggesting that these populations are adapting to climate change. However, the southern caribou populations that are experiencing less rapid environmental changes had offspring at their usual time. The timing of having offspring was also affected by the elevation of the population’s home range. Elevation information came from ArcticDEM, a public-private partnership to create digital elevation models that is funded in part by NASA. Lastly, the researchers used data from several studies in the AAMA database to figure out how various predator and prey species – black bears, grizzly bears, caribou, moose and wolves – are affected by higher temperatures and increased precipitation. The data for temperature, and precipitation in the form of rain and snow came from NASA’s Daily Surface Weather and Climatological Summaries, or Daymet. The trends in movement for different species varied widely: some species move more when summer temperatures are higher while others move less, moose and wolves move less in winters with higher snowfalls, and increased summer rain didn’t seem to change movement patterns for any species. But, overall, predator species seemed to respond to climate change differently than prey species. That causes a mismatch between predators and the prey they hunt for food. To determine the impacts of this mismatch, researchers will need to continue monitoring these populations. “More and more, the ecosystem that should be tightly coordinated is getting out of whack,” said Bohrer.
  • US-European Mission Launches to Monitor the World's Oceans
    A joint U.S.-European satellite built to monitor global sea levels lifted off on a SpaceX Falcon 9 rocket from Space Launch Complex 4E at Vandenberg Air Force Base in California Saturday at 9:17 a.m. PST (12:17 p.m. EST). About the size of a small pickup truck, Sentinel-6 Michael Freilich will extend a nearly 30-year continuous dataset on sea level collected by an ongoing collaboration of U.S. and European satellites while enhancing weather forecasts and providing detailed information on large-scale ocean currents to support ship navigation near coastlines. "The Earth is changing, and this satellite will help deepen our understanding of how," said Karen St. Germain, director of NASA's Earth Science Division. "The changing Earth processes are affecting sea level globally, but the impact on local communities varies widely. International collaboration is critical to both understanding these changes and informing coastal communities around the world." Get NASA's Climate Change News: Subscribe to the Newsletter » After arriving in orbit, the spacecraft separated from the rocket's second stage and unfolded its twin sets of solar arrays. Ground controllers successfully acquired the satellite's signal, and initial telemetry reports showed the spacecraft in good health. Sentinel-6 Michael Freilich will now undergo a series of exhaustive checks and calibrations before it starts collecting science data in a few months' time. NASA and SpaceX Launch U.S.-European Mission to Monitor World’s Ocean (Recap) Continuing the Legacy The spacecraft is named in honor of Michael Freilich, the former director of NASA's Earth Science Division, who was a leading figure in advancing ocean observations from space. Freilich passed away Aug. 5, 2020. His close family and friends attended the launch of the satellite that now carries his name. "Michael was a tireless force in Earth sciences. Climate change and sea level rise know no national borders, and he championed international collaboration to confront the challenge," said ESA (European Space Agency) Director of Earth Observation Programmes Josef Aschbacher. "It's fitting that a satellite in his name will continue the 'gold standard' of sea level measurements for the next half-decade. This European-U.S. cooperation is exemplary and will pave the way for more cooperation opportunities in Earth observation." "Mike helped ensure NASA was a steadfast partner with scientists and space agencies worldwide, and his love of oceanography and Earth science helped us improve understanding of our beautiful planet," added Thomas Zurbuchen, NASA associate administrator for science at the agency's headquarters. "This satellite so graciously named for him by our European partners will carry out the critical work Mike so believed in - adding to a legacy of crucial data about our oceans and paying it forward for the benefit of future generations." Sentinel-6 Michael Freilich will continue the sea level record that began in 1992 with the TOPEX/Poseidon satellite and continued with Jason-1 (2001), OSTM/Jason-2 (2008), and eventually Jason-3, which has been observing the oceans since 2016. Together, these satellites have provided a nearly 30-year record ofprecise measurements of sea level height while tracking the rate at which our oceans are rising in response to our warming climate. Sentinel-6 Michael Freilich will pass the baton to its twin, Sentinel-6B, in 2025, extending the current climate record at least another 10 years between the two satellites. Global Science Impact This latest mission marks the first international involvement in Copernicus, the European Union's Earth Observation Programme. Along with measuring sea levels for almost the entire globe, Sentinel-6 Michael Freilich's suite of scientific instruments will also make atmospheric measurements that can be used to complement climate models and help meteorologists make better weather forecasts. "NASA is but one of several partners involved in Sentinel-6 Michael Freilich, but this satellite speaks to the very core of our mission," said NASA Administrator Jim Bridenstine. "Whether 800 miles above Earth with this remarkable spacecraft or traveling to Mars to look for signs of life, whether providing farmers with agricultural data or aiding first responders with our Disasters program, we are tirelessly committed not just to learning and exploring, but to having an impact where it's needed." The initial orbit of Sentinel-6 Michael Freilich is about 12.5 miles (20.1 kilometers) lower than its ultimate operational orbit of 830 miles (1,336 kilometers). In less than a month, the satellite will receive commands to raise its orbit, trailing Jason-3 by about 30 seconds. Mission scientists and engineers will then spend about a year cross-calibrating data collected by the two satellites to ensure the continuity of sea level measurements from one satellite to the next. Sentinel-6 Michael Freilich will then take over as the primary sea level satellite and Jason-3 will provide a supporting role until the end of its mission. "This mission is the very essence of partnership, precision, and incredible long-term focus," said Michael Watkins, director of NASA's Jet Propulsion Laboratory in Southern California, which manages the mission. "Sentinel-6 Michael Freilich not only provides a critical measurement,it is essential for continuing this historic multi-decadal sea level record." Sentinel-6 Michael Freilich and Sentinel-6B compose the Sentinel-6/Jason-CS (Continuity of Service) mission developed in partnership with ESA. ESA is developing the new Sentinel family of missions to support the operational needs of the Copernicus program, managed by the European Commission. Other partners include the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and National Oceanic and Atmospheric Administration, with funding support from the European Commission and technical support from France's National Centre for Space Studies. "The data from this satellite, which is so critical for climate monitoring and weather forecasting, will be of unprecedented accuracy," said EUMETSAT Director-General Alain Ratier. "These data, which can only be obtained by measurements from space, will bring a wide range of benefits to people around the globe, from safer ocean travel to more precise prediction of hurricane paths, from greater understanding of sea level rise to more accurate seasonal weather forecasts, and so much more." JPL, a division of Caltech in Pasadena, California, is contributing three science instruments to each Sentinel-6 satellite: the Advanced Microwave Radiometer for Climate, the Global Navigation Satellite System - Radio Occultation, and the Laser Retroreflector Array. NASA is also contributing launch services, ground systems supporting operation of the NASA science instruments, the science data processors for two of these instruments, and support for the U.S. component of the international Ocean Surface Topography Science Team. The launch is managed by NASA's Launch Services Program, based at the agency's Kennedy Space Center in Florida. Read the Sentinel-6 Michael Freilich press kit: https://www.jpl.nasa.gov/news/press_kits/sentinel-6/ To learn more about Sentinel-6 Michael Freilich, visit: https://www.nasa.gov/sentinel-6 https://www.esa.int/Sentinel-6 https://edefis.eu/CopernicusFactsheets https://www.eumetsat.int/website/home/Copernicus/copernicus-sentinel-6/index.html
  • Sentinel-6 Michael Freilich Launch Updates
    The world's newest sea level-measuring satellite, Sentinel-6 Michael Freilich, is scheduled to launch on Saturday, Nov. 21, at 9:17 a.m. PT. Here are some resources for keeping up with the latest on this event: To watch the event: https://www.nasa.gov/nasalive https://www.youtube.com/NASA General launch updates: https://blogs.nasa.gov/sentinel-6/ (official source) https://www.jpl.nasa.gov/ Social media channels to follow (using the hashtag #SeeingTheSeas): Twitter: @NASA, @NASAEarth, @NASA_JPL, @NASASocial, @ESA, @ESA_EO, @EU_Commission, @NOAA, @CNES, @Eumetsat, @CopernicusEU, @defis_eu @SpaceX, @NASA_LSP, @NASA360, 30thSpaceWing Facebook: NASA, NASA JPL, NASA Earth, NASA LSP, 30thSpaceWing Instagram: NASA, NASAJPL, NASAEarth, Vandenberg_AFB Other information: https://www.nasa.gov/sentinel-6 (news, media resources, and more) Pre-launch and launch activities Launch timeline
  • Study: Urban Greenery Plays a Surprising Role in Greenhouse Gas Emissions
    Burning fossil fuels in densely populated regions greatly increases the level of the greenhouse gas carbon dioxide. The largest carbon dioxide sources are cars, trucks, ports, power generation, and industry, including manufacturing. Urban greenery adds CO2 to the atmosphere when vegetation dies and decomposes, increasing total emissions. Urban vegetation also removes this gas from the atmosphere when it photosynthesizes, causing total measured emissions to drop. Understanding the role of urban vegetation is important for managing cities' green spaces and tracking the effects of other carbon sources. A recently published study showed that among the overall sources of carbon dioxide in urban environments, a fraction is from decaying trees, lawns, and other urban vegetation. The contribution is modest - about one-fifth of the measured CO2 contributed by the urban environment - and varies seasonally. This was more than researchers anticipated and underscores the complexity of tracking urban carbon emissions. Get NASA's Climate Change News: Subscribe to the Newsletter » The team behind the study made this discovery by tracing carbon dioxide sources with carbon-14, a rare form of carbon that occurs naturally in Earth's atmosphere and is absorbed by living things as they grow. Carbon-14's presence in organic materials is the basis of radiocarbon dating and serves as a powerful tool to distinguish the carbon dioxide produced by fossil fuel combustion from that produced by decomposing vegetation and other organic matter. The carbon found in coal, oil, and natural gas is hundreds of millions of years old; all of its carbon-14 decayed long ago. The researchers measured levels of "excess" carbon dioxide, or the amount that's above what can be attributed to natural, background sources. Focusing on the "Los Angeles megacity" - a multicity region encompassing nearly 6,000 square miles (15,000 square kilometers) and 18 million people - they found that, over the course of a year, urban greenery accounts for about one-fifth of the excess carbon dioxide observed in the air over the study area. There were additional, small contributions from biofuels, such as ethanol, and from human metabolism. The team included scientists from the National Oceanic and Atmospheric Administration (NOAA), NASA's Jet Propulsion Laboratory, and the University of Colorado. The measurements were performed on air samples collected from late 2014 to early 2016, using air-sampling devices placed in three sites across the L.A. basin. "Before we started the experiment, we thought we were going to see almost all anthropogenic [human-caused] emissions, given the volume of traffic in L.A.," said study co-author Charles Miller, a research scientist at JPL. "We were able to find out it wasn't all due to fossil fuel combustion." While the finding in Southern California was a surprise, the contribution from urban greenery might be even more pronounced in many cities of the tropics. "In the tropics and subtropics - those places where vegetation grows like crazy and there are high rates of decomposition - you might find much larger fractions," Miller added. "Without the vegetation component factored into estimates [for total emissions], we will systematically overestimate fossil fuel emissions. This is important to those responsible for both reporting and mitigation." The study is part of a larger, years-long effort involving a variety of researchers called the "Megacities Carbon Project." It shows the importance of managing carbon in cities from a "holistic" point of view, said study co-author Riley Duren, now a researcher at the University of Arizona and a JPL engineering fellow. "Understanding these relationships can help planners design and manage green spaces in ways that pull as much carbon out of the atmosphere as possible and store it permanently while minimizing the release of emissions of CO2 from plants as they dry out or during non-growing seasons, ideally with native, drought-tolerant species," Duren added. Another Kind of Carbon Carbon-14 is mainly created by gamma rays from the Sun in Earth's upper atmosphere, where it becomes chemically incorporated into carbon dioxide. It is transported by winds downward toward Earth's surface and then around the planet. Living organisms absorb carbon dioxide that contains both "regular" carbon (carbon-12) and carbon-14. Once an organism dies, the carbon-14, which is radioactive, decays away over time. Through radiocarbon dating, scientists have long used carbon-14 as a natural "clock" for estimating the age of dead plants and animals as well as the age of materials made from them - for instance, fragments of antique woolen blankets or the dregs of wine in the bottom of ancient urns. "Fossil fuel carbon buried in the ground hundreds of millions of years ago has exactly zero carbon-14 in it," Miller said. Carbon from recent biological sources, on the other hand, shows a clear carbon-14 signal. "When all that green stuff we're used to in Los Angeles - the plants, grasses, palm fronds - starts to decay and release its carbon dioxide back into the atmosphere, that has a non-zero carbon-14 content," he added. "By looking at the carbon-14 value we observe, we come up with the relative fraction of the biological contribution to the total amount of carbon dioxide. The fact that the fossil-fuel carbon-14 is zero makes the math much simpler." Scientists also saw a carbon-14 connection in the seasonal ups and downs of carbon dioxide. Carbon-14 dropped sharply in the L.A. basin in July during the study period. That's when watering urban landscaping - city parks, residential lawns, golf courses, and the like - peaked, causing vigorous growth. In turn, the growing plant tissue led to peak carbon-14 absorption, resulting in that sharp drop found in air samples. Absorption among California's native forests, grasses, and shrubs peaked in early spring, a response to the region's rainfall patterns. Measuring carbon-14 will likely become important for more precisely evaluating carbon dioxide in other large urban areas. To effectively reduce fossil-fuel emissions, researchers need to quantify the background sources of carbon dioxide in global cities to understand how it varies with climate, latitude, degree of industrialization, and the like, Miller said, noting that there's more work to be done. The latest study fits into NASA's broader portfolio of work on the carbon cycle, such as NASA's Orbiting Carbon Observatory-3 on the International Space Station and its predecessor OCO-2, which is in Sun-synchronous oribt. "We need to work with our colleagues in other urban areas around the world to understand these new results," he said. News Media Contacts Ian J. O'Neill / Jane J. Lee Jet Propulsion Laboratory, Pasadena, Calif. 818-354-2649 / 818-354-0307 ian.j.oneill@jpl.nasa.gov / jane.j.lee@jpl.nasa.gov
  • NASA TV to Air Sentinel-6 Michael Freilich Launch, Prelaunch Activities
    NASA is targeting 12:17 p.m. EST (9:17 a.m. PST) Saturday, Nov. 21, for the launch of the Sentinel-6 Michael Freilich satellite, the first of two identical satellites to head into Earth orbit five years apart to continue sea level observations for at least the next decade. Live launch coverage will begin at 11:45 a.m. EST (8:45 a.m. PST), on NASA Television and the agency's website, with prelaunch and science briefings the day before on Nov. 20. Get NASA's Climate Change News: Subscribe to the Newsletter » Sentinel-6 Michael Freilich will head into orbit on a SpaceX Falcon 9 rocket from Space Launch Complex 4 at Vandenberg Air Force Base (VAFB) in California. The launch is managed by NASA's Launch Services Program, based at the agency's Kennedy Space Center in Florida. NASA's Jet Propulsion Laboratory in Southern California manages the agency's contribution to the mission. The Sentinel-6 Michael Freilich satellite is named in honor of the former director of NASA's Earth Science Division, who was instrumental in advancing space-based ocean measurements. It follows the most recent U.S.-European sea level observation satellite, Jason-3, which launched in 2016 and is currently providing high-precision and timely observations of the topography of the global ocean. The Sentinel-6/Jason-CS (Continuity of Service) mission, consisting of the Sentinel-6 Michael Freilich and Sentinel-6B satellites, is being jointly developed by ESA (European Space Agency), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), NASA, and the National Oceanic and Atmospheric Administration (NOAA), with funding support from the European Commission and support from France's National Centre for Space Studies (CNES). The Sentinel-6/Jason-CS mission is part of Copernicus, the European Union's Earth observation program, managed by the European Commission. Continuing the legacy of the Jason series missions, Sentinel-6/Jason-CS will extend the records of sea level into their fourth decade, collecting accurate measurements of sea surface height for more than 90% of the world's oceans, and providing crucial information for operational oceanography, marine meteorology, and climate studies. Sentinel-6 Michael Freilich's twin, Sentinel-6B, is scheduled to launch in 2025. NASA's contributions to the Sentinel-6/Jason-CS mission are three science instruments for each of the two satellites: the Advanced Microwave Radiometer, the Global Navigation Satellite System - Radio Occultation, and the Laser Retroreflector Array. NASA is also contributing launch services, ground systems supporting operation of the NASA science instruments, the science data processors for two of these instruments, and support for the U.S. members of the international Ocean Surface Topography Science Team. Full mission coverage is as follows (all times Eastern): Friday, Nov. 20 3:30 p.m. - Sentinel-6 Michael Freilich Science Briefing with the following participants: Karen St. Germain, director, NASA Earth Science Division Craig Donlon, project scientist, ESA Remko Scharroo, project scientist, EUMETSAT Josh Willis, project scientist, JPL Deirdre Byrne, oceanographer, NOAA Luanne Thompson, oceanographer, University of Washington 5:00 p.m. - Sentinel-6 Michael Freilich Prelaunch News Conference with the following participants: Thomas Zurbuchen, associate administrator for Science Mission Directorate, NASA Headquarters Johann-Dietrich Wörner, director-general, ESA (prerecorded remarks) Pierrik Vuilleumier, project manager, ESA Tim Dunn, NASA launch director, Launch Services Program, Kennedy Parag Vaze, project manager, JPL Julianna Scheiman, program manager for NASA Launch Services, SpaceX Col. Anthony Mastalir, Commander, 30th Space Wing and Western Launch and Test Range, VAFB Capt. John Ott, weather officer, 30th Space Wing, VAFB 7:30 p.m. - NASA TV live prelaunch coverage begins with NASA Edge show This will air on NASA TV, as well as on the NASA Edge Facebook page and YouTube channel. Saturday, Nov. 21 11:45 a.m. - NASA TV live launch coverage begins Audio only of the news conferences and launch coverage will be carried on the NASA "V" circuits, which may be accessed by dialing 321-867-1220, -1240, -1260 or -7135. On launch day, "mission audio," the launch conductor's countdown activities without NASA TV launch commentary, will be carried on 321-867-7135. Other Activities Virtual NASA Social As we finalize launch preparations, we are excited to invite the public to join our virtual NASA Social (https://fb.me/e/1bC2vFNls). Stay up to date on the latest mission activities; interact with NASA, NOAA, ESA, and EUMETSAT team members in real time; and watch the launch of the SpaceX Falcon 9 rocket that will boost Sentinel-6 Michael Freilich into orbit for its journey #SeeingTheSeas Virtual Launch Passport Print, fold, and get ready to fill your virtual launch passport. Stamps will be emailed following launches to all registrants (who submit an email registration via Eventbrite). Passports available now: https://go.nasa.gov/364lPIt Watch and Engage on Social Media Stay connected with the mission on social media, and let people know you're following it on Twitter, Facebook, and Instagram using the hashtag #SeeingTheSeas and tag these accounts: Twitter: @NASA, @NASAEarth, @NASAClimate, @NASA_JPL, @NASASocial, @ESA, @ESA_EO, @EU_Commission, @NOAA, @CNES, @Eumetsat, @CopernicusEU, @defis_eu, @SpaceX, @NASA_LSP, @NASA360, 30thSpaceWing Facebook: NASA, NASA JPL, NASA Earth, NASA Climate Change, NASA LSP, 30thSpaceWing Instagram: NASA, NASAJPL, NASAEarth, Vandenberg_AFB For more information, visit: https://www.nasa.gov/sentinel-6 https://www.esa.int/Sentinel-6 https://edefis.eu/CopernicusFactsheets News Media Contact Grey Hautaluoma NASA Headquarters, Washington 202-358-0668 grey.hautaluoma-1@nasa.gov Jane J. Lee / Ian J. O'Neill Jet Propulsion Laboratory, Pasadena, Calif. 818-354-0307 / 818-354-2649 jane.j.lee@jpl.nasa.gov / ian.j.oneill@jpl.nasa.gov Mary MacLaughlin / Kenna Pell Kennedy Space Center, Fla. 321-289-7960 / 321-501-0625 mary.maclaughlin@nasa.gov / kenna.m.pell@nasa.gov
  • Beating Back the Tides
    It was a sight you don’t normally see: a jellyfish lying dead in the middle of a parking lot partly submerged in water. But this was no ordinary parking lot. This particular section of asphalt in downtown Annapolis, Maryland, is among a growing number of areas prone to frequent flooding in the seaside town. The jellyfish had slipped in from the Chesapeake Bay through an opening in the seawall. “You can literally kayak from the bay right into this parking lot,” said NOAA oceanographer William Sweet on the September day that we visited. The tide was relatively low that day. On days with the highest tides of the year, whole parking lots and streets in Annapolis are underwater, causing delays and traffic congestion. Compromise Street, a major road into town, is often forced to shut down, slowing response times for firefighters and other first responders. Local businesses have lost as much as $172,000 a year, or 1.4% of their annual revenue, due to high-tide floods, according to a study published in 2019 in the journal Science Advances. High-tide floods, also known as nuisance floods, sunny-day floods, and recurrent tidal floods, occur “when tides reach anywhere from 1.75 to 2 feet above the daily average high tide and start spilling onto streets or bubbling up from storm drains,” according to an annual report on the subject by the National Oceanic and Atmospheric Administration (NOAA.) These floods are usually not related to storms; they typically occur during high tides, and they impact people’s lives. Because of rising seas driven by climate change, the frequency of this kind of flood has dramatically increased in recent years. Get NASA's Climate Change News: Subscribe to the Newsletter » Sea level rise is often spoken of in future terms, including projections for impacts we’re likely to see by the end of the century. But in many communities in the U.S., sea level rise is already a factor in people’s lives in the form of high-tide flooding. Credit: NASA Between 2000 and 2015, high-tide flooding in the U.S. doubled from an average of three days per year to six along the Northeast Atlantic, according to a 2018 NOAA report. It is especially common along the East Coast and Gulf Coast, where the frequency is up by roughly 200% over the last two decades. In some areas like Annapolis, the numbers are even more extreme. Annapolis had a record 18 days of high-tide flooding from May 2019 to April 2020, according to flooding thresholds for the city established by NOAA. That’s up from the previous record of 12 days in 2018. Before 2015, the record number of high-tide flood days in one year was seven, and the yearly average of high-tide floods from 1995 to 2005 was two. This plot shows the trend of high-tide flooding days in Annapolis, Md. Already, it’s disrupting people’s lives, said Ben Hamlington, a research scientist at NASA’s Jet Propulsion Laboratory. “It impacts your ability to go to work, to drop the kids off at daycare, to go to the grocery store.” Hamlington leads the NASA Sea Level Change team, which studies the roles that ocean, ice, and land play in high-tide flooding. In March 2019, the NASA team met in Annapolis with 35 local and state government officials to discuss the challenges coastal cities are facing and provide science and research to help them make decisions. Future projections are gloomier. Without additional flood management efforts, the frequency of this kind of flooding is projected to double or triple by 2030, and could be as much as 15-fold higher by 2050. This means high-tide flooding could occur 180 days a year in some locations, “effectively becoming the new high tide,” the report reads. Plus, floodwater can travel up pipes, compromising both stormwater and wastewater systems. In Norfolk and Chesapeake, Virginia, lawn fertilizers get flushed by tidal floods from people’s yards and into the Elizabeth River, feeding harmful algal blooms, said Derek Loftis, an assistant professor at the Center for Coastal Resources Management with the Virginia Institute of Marine Science, who studies the issue. Sea level rise can feel abstract, like something looming far off in the future. But if you want to see it happening in real-time, look no further than these floods. “It's not an esoteric discussion any longer,” Sweet said. “It's real.” What Drives It Think of high-tide flooding as a layering of different processes on different time scales, said JPL’s Hamlington. On the shortest time scale, you have the tides themselves, which are driven by the gravitational pull of the Moon. The highest high tides typically occur during full moons and new moons, when the Moon, the Sun and Earth are nearly aligned. During these times, the pull is stronger as the gravity of the Sun reinforces the gravity of the Moon. Winds can also influence how high the tides come in. The Chesapeake Bay, for example, is prone to winds from the North and the South. "Winds from the South shove water up the bay, and Northeasterly winds can pile up water regionally along much of the East coast, including the bay." Sweet said. “And we're not talking about extreme winds, we're talking about the kind of winds that we like when we go sailing: 15, 20-knot winds.” Then there are the climate patterns like El Niño, which lead to higher-than-normal sea levels along both the U.S. East and West coasts. Subsidence, the settling or sinking of land, also has a powerful role to play. Subsidence partly stems from natural causes, like the compaction of sediments in the Mississippi Delta and the movement of land due to natural geologic processes, but also from the extraction of groundwater and natural gas along the Gulf coast. And, of course, the most powerful driver is sea level rise itself. The ocean is rising at about 3.3 millimeters, or 0.13 inches a year, mostly due to the melting of land-based ice and the thermal expansion of ocean water, according to NASA. This rate is accelerating over time, by about an additional 1 millimeter per year roughly every decade. Measuring High-Tide Flooding The best flood projections must take all of these processes into account, and that requires a view from space, Hamlington said. “Understanding the future of high-tide flooding is a little bit like a puzzle,” Hamlington said. “We’re trying to put together the pieces. And the satellites we have available really help us do that.” Hamlington’s team relies on a suite of radar altimeter satellites to measure the height of the ocean surface. From an altitude of 830 miles (1,336 kilometers), these altimeters bounce signals off the ocean surface and measure the time it takes them to return to the spacecraft. “To study large-scale climate signals like El Niño, we need to have a broad view of the ocean,” Hamlington said. “The altimeters give us really accurate measurements of sea surface height on these very large scales.” They include the Jason-3 satellite, an international partnership between NOAA, NASA, the French government’s National Centre for Space Studies and EUMETSAT, along with its predecessors, Jason-1, Jason-2 and TOPEX/Poseidon, which collectively form a consecutive record dating back to 1992. Sentinel-6 Michael Freilich will mark the latest satellite in the partners’ efforts. An artist's rendering of the Sentinel-6 Michael Freilich satellite. Credit: NASA These observations combine with other satellite data and with continuous measurements from about 2,000 tide gauges worldwide to fill in the pieces of that puzzle. The satellites fill in the gaps where the tide gauges are sparse. Mapping Rising Tides Satellite data also help scientists model and map high-tide flooding events. In coastal Virginia, for example, Loftis has helped create a model to predict the area’s highest high-tide floods of the year, and has paired it with a large citizen science effort to validate the location of those floodwaters. Over the years, he’s recruited hundreds of volunteers-turned-citizen scientists to fan out along the coastline and validate his projections by marking the height of the floodwaters with GPS tags. The effort began in Norfolk, but has expanded to volunteers across coastal Virginia and Maryland’s Eastern shore. The team relies on the Landsat 7 and Landsat 8 satellites from NASA and the U.S. Geological Survey (USGS), the Terra satellite’s ASTER (a contribution from Japan) and MODIS instruments, and NOAA’s GOES-16 geostationary satellite, to evaluate the model after the flood. He also believes that a new 98-feet (30-meter) mapping model that uses data from the NOAA-NASA Suomi-NPP and NOAA-20 polar-orbiting satellites might be helpful in the future. Loftis hopes these maps will help cities prepare for future floods as well as urban flood protection. “There previously wasn’t much of a frame of reference,” Loftis said. “Now we’ve got a map with volunteer data that confirms yes, this is what we saw with tens of thousands of data points.” High-tide flooding is not just a beachfront problem. It’s a problem that will increasingly impact urban areas like New York City, Philadelphia, Charleston and Miami, but also smaller communities along the coast, especially in back bays and estuaries, said David Kriebel, a professor of ocean engineering at the U.S. Naval Academy. It's likely to become a story of haves and have nots, he said. Some areas will have the means to afford the massive funding required to protect against it; others won’t. “I think we're going to end up with certain locations that are going to take big actions— New York City and Miami Beach are examples—and we're going to have other smaller communities that are going to have a hard time dealing with it,” he said. Building Defenses Half a mile up the road from Downtown Annapolis, the U.S. Naval Academy is also beating back water. McNair Road runs along the perimeter of campus, separating the academy’s indoor stadium from College Creek, a waterway that feeds into the Severn River, and eventually, the Chesapeake Bay. When the seawater gets high enough, it shoots up through the storm drains, flooding McNair Road, and at the same time, spills over onto Ramsay Road on the opposite side of the creek. Both roads have already flooded 20 times this year, and more than 40 times each in 2018 and 2019. Ramsay Road, which runs along the cemetery on the campus of the U.S. Naval Academy, flooded more than 40 times in 2018 and 2019. Credit: David Kriebel On a recent fall morning, Kriebel points out the many defenses the campus has built against rising water: A seawall built alongside the river, flood walls protecting campus buildings, and classroom floors and walls made of concrete or painted cinder block—materials more resistant to flooding than carpet, wood and drywall. Across the river, at Ramsay Road, high water levels frequently flood parts of the road that run alongside the cemetery where Naval Academy alumni, including former Sen. John McCain, are buried. The cemetery itself is on a hill, so it’s not in danger of flooding, but floodwater has been known to close the road on days that solemn services are planned. And in addition to the water that floods over roads, there’s the water lurking just below the road surface. “When the water is just below the roadbed on the one side,” Kriebel said, “it seeps through the gravel under the road and pops out the other side.” On top of the 40-some flood events occurring each year, he added, “there are literally hundreds of high tides that are just a few inches below the road surface today.” At the Naval Academy, they’re considering various flood protection options. One option at Ramsay Road is to abandon the road and relocate it. Another is to build another flood wall. But Kriebel suspects they’ll choose a third option, to elevate the road by about a foot, and eventually raise the athletic field that runs alongside it too. Still, he said, the water is rising fast, and much of this flood protection will only last for a few decades. At that point, additional measures will have to be taken. “You can build walls, you can add inflow preventers and you can protect areas that are worth protecting, but eventually, water’s going to find its way through the holes,” Sweet said. “You’re not really meant to hold back the tides.”
  • NASA Watches Sea Level Rise from Space, and its Centers' Windows
    The two-thirds of Earth covered by water may jeopardize up to two-thirds of NASA's infrastructure built within mere feet of sea level. Some NASA centers and facilities are located in coastal real estate because the shoreline is a safer, less inhabited surrounding if something goes wrong. But now these launch pads, laboratories, airfields, and testing facilities are potentially at risk because of sea level rise. A look at how NASA is dealing with the threat of sea level rise to its coastal infrastructure, particularly at Langley Research Center in Hampton, Virginia, and Ames Research Center in Mountain View, California. Credit: Joe Atkinson / Kevin Anderson / Rob Lorkiewicz / Gary Banziger. 1998 flood footage courtesy of Santa Clara Valley Water District. As Earth’s sea levels rise, so does the potential damage from storms, storm surges, and extreme weather events. In 2005, the costliest tropical cyclone on record at the time – Hurricane Katrina – barreled over the Gulf of Mexico, knocking out the power at NASA’s Michoud Assembly Facility in New Orleans. It was matched in 2017 by Hurricane Harvey, which flooded the Sonny Carter Training Facility where astronauts train at NASA’s Johnson Space Center in Houston. Protective sand dunes at NASA’s Kennedy Space Center in Florida were swept away in the winds and high tides generated by Hurricane Sandy in 2014, and then again by Hurricane Mathew in 2016. The roads leading to NASA's Langley Research Center in Hampton, Virginia increasingly become inundated with water, cutting off access to buildings. On the other side of the country in the wetlands surrounding the San Francisco Bay, the airfields at NASA’s Ames Research Center in Silicon Valley, California face the same threat. Get NASA's Climate Change News: Subscribe to the Newsletter » In 2015, NASA reviewed these vulnerabilities to sea level rise through its Climate Adaptation Science Investigators (CASI) Working Group, and summarized some of the findings in an article that appeared on NASA’s Earth Observatory website. The red shaded areas show the land around five NASA centers that would be inundated by 12 inches (30 centimeters) of sea level rise. NASA’s CASI Working Group concluded between 5 to 24 inches (13 to 61 centimeters) of sea level rise is projected for the coastal centers by 2050. Credit: NASA Earth Observatory maps by Joshua Stevens based on data from NASA’s Climate Adaptation Science Investigators Working Group The accepted rate of global sea level rise sounds deceptively small, at 3.3 millimeters per year, just over one-tenth of an inch. But that rise is accelerating, going from about 0.1 inch (2.5 millimeters) per year in the 1990s to about 0.13 inches (3.4 millimeters) per year today. When combined with sinking lands and the increasing occurrence of natural disasters and storm surges, those millimeters add up to cause concern for many areas around the globe, including several NASA center locations. All of NASA’s buildings and grounds represent more than $32 billion in infrastructure. Many also hold sentimental value as the structures upon which NASA’s history was built. So, for those at risk from rising seas, the agency is taking steps to prepare. NASA's Kennedy Space Center in Florida and its historic launchpads which are still in use today are threatened by the waves from the Atlantic which are just meters away. Credit: NASA/Robert Simmon, using ALI data distributed by the USGS Global Visualization Viewer Building Up At Kennedy, there are parts of launchpad 39A—the site from which Apollo astronauts lifted off on their Moonward journeys—that are expected to start flooding periodically from 2020 onward instead of the occasional sporadic flooding events experienced in the past. The weather that precedes flooding would generally scrub a scheduled launch anyway, but the frequency and size of flooding events are expected to continue increasing over the next few decades and could eventually damage the existing structures. In response, the spaceport initiated a Shoreline Restoration Project to add 450,000 cubic yards of beach sand—that’s the equivalent of filling about 150 Olympic-sized swimming pools—to Kennedy’s 3.5 miles of coastline. This sedimentary solution is slated for completion by March 2021, and could prove to be crucial for continued use by current lessee, SpaceX, for its upcoming Falcon Rocket launches. But it is not a permanent fix. Like Kennedy, NASA’s Wallops Flight Facility on Wallops Island, Virginia has its launch pads and buildings within a few hundred feet of the Atlantic Ocean. Assistant Administrator for NASA’s Office of Strategic Infrastructure, Calvin Williams, says that due to the ongoing erosion on the barrier island, the center has replenished the beaches five times already, with the costs averaging around $14 million per project. Another concern of flooding events and raising water levels is access to the facilities when roads are flooded or damaged. High tide flooding, also known as nuisance flooding due to the inconvenience of associated road closures, is estimated to have tripled in frequency compared to 50 years ago. At Kennedy, approximately 1.5 miles of roadways need to be raised up to 1 foot to avoid degradation before the end of the decade; by 2059, that grows to 20 miles of roadway raised up to 2 feet, and near the end of the century virtually all of its roadways (nearly 100 miles) will need work to remain above water. Battening Down or Getting Out A different approach is under way in Virginia, Houston, New Orleans, and Silicon Valley. The centers at these locations are focusing on hardening at-risk buildings, and in some cases even moving operations, both of which are taking precedence over reinforcing the surrounding environment. “We've been demolishing facilities that are in highly vulnerable areas and building all of our new facilities at our higher elevations," said Loretta Kelemen, director of the Center Operations Directorate at Langley in Hampton, Virginia. “If you can't move the facility, you need to harden it against the storms.” At Johnson Space Center in Houston, hardening includes flood resistant doors, increased water intake systems, and raised guard shacks so that important operations like mission control and astronaut training are less likely to be affected by flooding. In New Orleans, Michoud sits below sea level and could have been destroyed during Hurricane Katrina if not for an existing onsite pumping system that moved up to 250,000 gallons of water per minute. Since then, the facility doubled its pumping capacity to protect the massive manufacturing plant—which includes a 43-acre building that previously housed Saturn rockets and space shuttle boosters, and where the Space Launch System (SLS) is now being assembled—from additional weather events. Kelemen says the data coming from scientists both at NASA and from outside the agency are alarming. The most conservative estimates predict at least a 15-inch sea level rise by 2080 but indicate a much greater impact if the rate of sea level rise continues accelerating as it has done in past decades. For Langley, sea level rise concerns are compounded by area subsidence – a sinking of the landmass below the facilities. Precision measurements at NASA Langley show it is sinking 0.08 inches (2 millimeters) a year, which means its effective rate of sea level rise is closer to 0.24 inches (6 millimeters) per year. According to Garrett Turner, an environmental engineer at Ames, its Silicon Valley campus in Mountain View, California is also dealing with subsidence as a result of regional over-pumping of groundwater. Ames and Langley are among the oldest NASA centers, with buildings dating back to the early- and mid-1900s. Both now share a long-term plan for shifting their operations to higher elevations to avoid the sea level rise projected within the century. “Our master plan has envisioned taking facilities that are in the current hundred-year flood plain and relocating them, and relocating the entire campus, farther south—which is several feet higher and has a much lower expected impact from sea level rise,” Turner said. “I don't know if we are going to move fast enough to stay ahead of the sea level rise, but we're moving them as quickly as we can.” Looking Ahead These efforts aim to protect NASA’s missions by preserving the grounds and facilities that make them possible. The agency has been monitoring global temperatures, ice melt, and sea level rise as part of its science mission for decades. Now it is also using these data to prepare its own centers for the eventual impacts. This map shows the change in sea level between 1992 and 2014 measured by the TOPEX/Poseidon, Jason-1, Jason-2, and Jason-3 missions. Credit: NASA Scientific Visualization Studio images by Kel Elkins, using data from JASON-1, JASON-2, and TOPEX/Poseidon. “We want to make sure that we are taking the necessary steps to ensure that in the future we have launch facilities and research facilities that can continue the mission of NASA,” said Williams. “That's why we take sea level rise and climate change very seriously.” Some of the past missions tracking these changes include the TOPEX-Poseidon and altimetric satellite Jason-1, joint ventures between the Centre National d'Etudes Spatiales and NASA, as well as Jason-1’s successors Jason-2 and Jason 3, a cooperation between NASA, CNES, the National Oceanic and Atmospheric Administration (NOAA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). These have provided scientists with a detailed topography of the oceans. The Gravity Recovery and Climate Experiment (GRACE) and GRACE-Follow On satellites—the German Aerospace Center, and NASA and the GFZ German Research Centre for Geosciences—as well as the Ice, Cloud, and land Elevation Satellite (ICESat) and ICESat-2, have also helped track sea level rise by monitoring global ice mass and water movement. The Sentinel-6 Michael Freilich satellite—developed jointly by NASA, the European Space Agency (ESA) in the context of the European Copernicus program led by the European Commission, EUMETSAT, and NOAA, (with funding support from the European Commission and contributions from CNES)—will launch from Vandenberg Air Force Base near Santa Barbara, California. The satellite will use electromagnetic signals bouncing off the ocean’s surface to make some of the most accurate measurements of sea levels to date. It will be followed by a second satellite in 2025, and together they will constitute a nearly 30-year record of changing sea levels, informing scientists, decision-makers, and NASA’s facilities managers alike.
  • Changing Pacific Conditions Raise Sea Level Along U.S. West Coast
    Ask your average resident of California, Oregon, or Washington to name the natural hazard that concerns them most and sea level rise probably won’t bubble to the top of the list. After all, the region is better known for its wildfires, earthquakes, heat waves, and mudslides. But those who live along the coastline know better. They’ve seen first-hand the effects of coastal erosion, beach loss, storm damage, and tidal flooding resulting from sea level rise. In some locations, it’s a constant battle to hold back the sea. Yet during the 1990s and 2000s, natural climate cycles actually suppressed the rate of sea level rise off the U.S. West Coast. That lull appears to be over. Changing Pacific Ocean and atmospheric conditions have stirred up Earth’s largest ocean and redistributed its heat, piling up warm waters along U.S. western shores and raising sea level in the process. Changing conditions in the Pacific have stirred up Earth’s largest ocean and redistributed its heat, piling up warm waters along U.S. western shores and raising sea level in the process. Credit: NASA Global sea level has risen an average of 0.13 inches (3.3 millimeters) a year since satellites began precisely measuring sea surface height following the 1992 launch of the Topex/Poseidon mission, a partnership between NASA and Centre National D’Etudes Spatiales in France. In the northeastern Pacific off the U.S. West Coast, however, sea level actually fell at a rate of around 0.04 inches (1 millimeter) per year during the 1990s and 2000s. Then around 2010, sea level along the U.S. West Coast began steadily increasing, with the largest rise occurring in 2014-2016. While the rate has stabilized since then, it remains higher than the global average. Get NASA's Climate Change News: Subscribe to the Newsletter » Ben Hamlington is a NASA Jet Propulsion Laboratory scientist working with a group of researchers to study how U.S. West Coast sea level may change in the next couple of decades. The researchers are studying data from satellites and tide gauges to help understand the difference between sea level changes caused by rising global temperatures and those due to naturally occurring cyclic processes, particularly the impacts of two natural climate cycles that link conditions in the Pacific Ocean with the atmosphere above: The El Niño-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). What his team has seen is concerning. Regional mean sea-level trends between January 1993 and October 2019. Areas in red show where sea level has risen while blue areas indicate where sea level has fallen. Regional differences in sea-level rise clearly put some places at risk more than others. Credit: NASA's Scientific Visualization Studio Download in HD formats from NASA Goddard's Scientifc Visualization Studio “Based on available observations, we appear to be in an elevated period of sea level rise along the U.S. West Coast,” said Hamlington, who leads NASA’s Sea Level Change Science Team. “We’ve seen an increase of about 0.4 inches (10 millimeters) a year for the past five years and, based on available past observations and modeled data, we expect to see similar increases for the next few years. Based on historical data, there are indications that elevated sea level rise rates could persist much longer. We could see 20 years of elevated rates.” What’s going on, and will it continue? To understand West Coast sea level variations, it helps to get a big picture of ENSO and the PDO and how they influence regional sea levels. ENSO, the PDO, and Their Influences An El Niño occurs when the eastern Pacific ocean warms. When it warms, the ocean water expands, causing sea level to rise, as seen here in the Jason-2 data of sea surface height shown in red. Credit: NASA Earth Observatory map by Joshua Stevens, using Jason-2 data provided by Akiko Kayashi and Bill Patzert, NASA/JPL Ocean Surface Topography Team. Seen from space, changing Pacific sea surface heights reveal a seesaw-like pattern in the western and eastern tropical Pacific. When sea level is higher than average in the western Pacific, as it was during the first half of the satellite altimeter record, it’s lower than average on the eastern side, and vice versa. This phenomenon is driven on shorter timescales by ENSO and the PDO. ENSO is a recurring pattern of interactions between the ocean and atmosphere that affects ocean temperatures in the central and eastern Pacific Ocean, influencing sea level, global climate and weather patterns. It’s best known for its opposing phases: El Niño and La Niña. During El Niño, westward-blowing trade winds in the western tropical Pacific along the equator weaken, allowing warm waters to move east toward the Americas. During La Niña, these trade winds are stronger than normal, and cold water that usually sits along the South American coast is pushed to the central Pacific. These events happen every few years and persist for six to 18 months. El Niños can increase West Coast sea level by more than 7.9 inches (20 centimeters) over this time period, while La Niñas can decrease it by a similar amount. Both El Niño and La Niña play on a larger stage that operates on decade-long timescales. The PDO is a long-term pattern of change that alternates between warm and cool phases about every five to 20 years. In the PDO’s cool phase, warm water forms a horseshoe-shaped pattern connecting the north, west and south Pacific, with a pool of cool water in the middle that extends up the U.S. West Coast. In its warm phase, these warm and cool regions are reversed, and warm water occupies the pool in the middle and along the West Coast. Shifts in the PDO phase have significant impacts on global climate and weather, affecting Pacific and Atlantic hurricane activity, droughts and flooding around the Pacific basin, marine ecosystems, global land temperature patterns, and Pacific basin sea level variations. For West Coast communities threatened by rising seas, predicting when the seesaw will swing the other way is critical. “People have been lulled into a false sense of security because we’ve seen very little sea level rise along the West Coast in recent decades,” said Hamlington. “Persistent cool PDO phases have suppressed sea level, locally masking the long-term rise due to global warming from human activities. Around 2010, the PDO began a shift from a cool to a warm phase and sea level is now increasing. As global sea level rises, the impacts of these natural climate swings are going to get worse.” Sea surface temperature anomaly pattern associated with the positive (or warm) phase of the Pacific Decadal Oscillation (PDO). Red shading indicates where sea surface temperatures are above average, while blue shading shows where temperatures are below average. During negative (cold) phases, the pattern reverses. Credit: Image adapted by NOAA Climate.gov from original by Matt Newman based on NOAA ERSSTv4 data Oceanographer William Sweet of the National Oceanic and Atmospheric Administration’s (NOAA) National Ocean Service in Silver Spring, Maryland, believes El Niño will drive impacts on the West Coast in the near term. “Cycling into the warm phase of the PDO tends to increase the frequency and severity of El Niños, resulting in higher sea level during high tides,” he said. “El Niño events are really glimpses into the future, because decades of sea level rise can occur within one year, at least based on historical measurements.” Hamlington’s team is combining satellite and tide gauge data with model projections of sea level change to assess past, present and future trends and determine the processes behind them. “We have tide gauge data going back to the early 20th century, even as far as 1854 for San Francisco,” he said. “When we look at the data, we see periods of elevated sea level rates caused by combined ENSO events and PDO shifts.” Cliff erosion is a common storm-induced hazard along the U.S. West Coast. Credit: USGS Widely Varying Impacts Hamlington said if the current sea level rise trend continues, we’ll likely see increased coastal erosion and high tide flooding, with impacts varying widely by location. Portions of the West Coast are fronted by sea cliffs made of sedimentary rock that erodes easily. Storm-generated waves collapse these coastal bluffs and cause coastlines to retreat, threatening vulnerable properties perched near the edge of sea cliffs and infrastructure like rail lines and highways. Runoff from land areas and prolonged winter rains compound the problem. A recent study by the U.S. Geological Survey found that the current rates of coastal erosion could double due to sea level rise by the end of this century. Perhaps the biggest wild card is high tide flooding. While the West Coast has largely been spared from these “sunny day” or “nuisance” floods, Sweet says these types of events are likely to occur more frequently in the future, with sea level rise, PDO variations and vertical land motion (sinking or rising of coastal lands) adding to the effect at certain times and places. Many coastal locations have a known threshold: a safety gap between regular high tide water levels and flooding conditions. Coastal communities are built a certain elevation above sea level with these natural fluctuations in mind. In many West Coast cities first built around the turn of the 20th century, safety gaps are now being exceeded due to the combination of long-term increases in sea level and these same natural fluctuations. A PDO shift can remove an additional 3.9 inches (10 centimeters) from the remaining safety gap, increasing flooding potential. Large waves and tides flood the intersection of Cortez Avenue and Seacoast Drive in San Diego County’s Imperial Beach. Credits: Mele Johnson, CCCIA Sweet said the type of flooding that currently impacts the West Coast most frequently is wave-related. This is best noticed during king tides. These tides, which are associated with the position of the Sun and Moon and are unrelated to climate change, bring an additional 200 to 300 millimeters (8 to 12 inches) of water. King tides provide a preview of what a foot of sea level rise will bring permanently to a shoreline. Sweet said it’s hard to envision sunny day flooding in California because it’s mostly flooding related to rough seas and breaking waves that people experience. As sea level continues to rise due to human activities and combines with El Niño events, at some point that water rise is going to become noticeable and problematic in areas that don’t experience breaking waves. Climate scientist Dan Cayan of Scripps Institution of Oceanography at UC San Diego, agrees. “Over time, nuisance flooding episodes have been increasing along the Southern California coast,” he said. “If sea level starts to increase at the mean global rate or higher, we’re going to see increasing flooding under relatively mild storms and during regular high tide situations. That’s going to be something to watch out for over the next decade, as it would be an enormous acceleration of what we’ve seen historically.” Cayan said enhanced sea level rise in San Diego would have the greatest impact when accompanied by a winter storm, and would be most pronounced if that storm happened during a spring tide. “In 1983 when we had a large El Niño, we had two cases where storms coincided with high tides. During that winter there were a lot of real estate losses along our coast, including Scripps Pier, which dates to 1914.” In this map of vertical land motion along California’s 1,000-mile (1,500-kilometer) coast, areas shown in blue are subsiding, with darker blue areas sinking faster than lighter blue ones. The areas shown in dark red are rising the fastest. The map was created by comparing thousands of scenes of synthetic aperture radar data collected between 2007 and 2011 with more collected between 2014 and 2018 to look for differences in the data. The radar data came from sensors on Japan’s Advanced Land Observing Satellite (ALOS) and Europe’s Sentinel-1A satellite. The researchers also made use of horizontal and vertical velocity data from ground-based receiving stations in the Global Navigation Satellite System (GNSS). Credit: NASA's Earth Observatory Read more Effects of Vertical Land Motion Another factor that will impact rising West Coast sea levels is vertical land movement – sinking or rising of coastal lands. In areas where land is sinking, sea level rises to a given flooding threshold level earlier. “It’s important to consider the impacts of vertical land motion when assessing coastal flooding threats,” Hamlington said. “Thanks to GPS data, we have long records of West Coast vertical land motion and they show some pretty high rates of subsidence (sinking) and considerable variability. La Jolla and San Diego have subsidence on the order of 0.08 inches (2 millimeters) per year since the 1990s. In San Francisco, it’s about 0.04 inches (1 millimeter) a year. This subsidence will add to and combine with the natural and human-caused increases we see from the ocean, making the impacts of sea level rise worse.” The Future Looking at the rest of this century, Hamlington said based on past observations and modeled projections of future changes, he expects West Coast sea level to continue its long-term increase, with significantly elevated and suppressed rates at different times due to natural year-to-year and decade-scale variations. A wild card is the future contribution to sea level rise from the Antarctic ice sheet, which, if melted, could lead to West Coast sea level rise greater than the global average. “It’s critical that planners account for the full range of substantial natural sea level variations in order to make informed planning decisions,” he said. “West Coast sea level variations due to the PDO and ENSO can lead to extended periods of elevated flood risk that compound the impacts from global sea level rise due to human-induced climate warming. It’s critical that we understand the processes that drive these variations and their magnitude.”
  • The Anatomy of Glacial Ice Loss
    Greenland and Antarctica are home to most of the world's glacial ice – including its only two ice sheets – making them areas of particular interest to scientists. Combined, the two regions also contain enough ice, that if it were to melt all at once, would raise sea levels by nearly 215 feet (65 meters) – making the study and understanding of them not just interesting, but crucial to our near-term adaptability and our long term survival in a changing world. Credit: NASA When an ice cube is exposed to a heat source, like warm water or air, it melts. So, it's no surprise that a warming climate is causing our glaciers and ice sheets to melt. However, predicting just how much the glaciers and ice sheets will melt and how quickly – key components of sea level rise – is not nearly as straightforward. Glaciers and ice sheets are far more complex structures than ice cubes. They form when snow accumulates and is compressed into ice by new snow over many years. As they grow, they begin to move slowly under the pressure of their own weight, dragging smaller rocks and debris across the land with them. Glacial ice that extends to cover large landmasses, as it does in Antarctica and Greenland, is considered an ice sheet. Get NASA's Climate Change News: Subscribe to the Newsletter » The processes that cause glaciers and ice sheets to lose mass are also more complex. An ice cube's surface melts when it's exposed to ambient (warm) air. And while warm air certainly melts the surface of glaciers and ice sheets, they're also significantly affected by other factors including the ocean water that surrounds them, the terrain (both land and ocean) over which they move, and even their own meltwater. Greenland and Antarctica are home to most of the world's glacial ice, including its only two ice sheets. These thick slabs of ice – some 10,000 feet (3,000 meters) and 15,000 feet (4,500 meters) thick, respectively – contain most of the freshwater stored on Earth, making them of particular interest to scientists. Combined, the two regions also contain enough ice that, if it were to melt all at once, would raise sea levels by nearly 215 feet (65 meters) – making the study and understanding of them not just interesting, but crucial to our near-term adaptability and our long-term survival in a changing world. Ice Loss in Greenland A glacier is considered "in balance" when the amount of snow that falls and accumulates at its surface (the accumulation zone) is equal to the amount of ice lost through melting, evaporation, calving and other processes. But with annual air temperatures in the Arctic increasing faster than anywhere else in the world, that balance is no longer achievable in Greenland. Warmer ocean waters surrounding the island's tidewater glaciers are also problematic. "It's basically like pointing a hairdryer at an ice cube, while the ice cube is also sitting in a warm pot of water," said Josh Willis, principal investigator of NASA's Oceans Melting Greenland (OMG), a project that is investigating the effects of ocean water temperature on melting ice in the region. "The glaciers are being melted by heat from above and below simultaneously." Although the warm air and the warm water contribute to melting individually, the interplay between the meltwater from the glacier and the warm ocean water also plays a significant role. When warm summer air melts the surface of a glacier, the meltwater bores holes down through the ice. It makes its way all the way down to the bottom of the glacier where it runs between the ice and the glacier bed, and eventually shoots out in a plume at the glacier base and into the surrounding ocean. The meltwater plume is lighter than the surrounding ocean water because it doesn't contain salt. So it rises toward the surface, mixing the warm ocean water upward in the process. The warm water then rubs up against the bottom of the glacier, causing even more of the glacier to melt. This often leads to calving – ice cracking and breaking off into large ice chunks (icebergs) – at the front end, or terminus of the glacier. Credit: NASA When warm summer air melts the surface of a glacier, the meltwater bores holes down through the ice. It makes its way all the way down to the bottom of the glacier where it runs between the ice and the glacier bed, and eventually shoots out in a plume at the glacier base and into the surrounding ocean. The meltwater plume is lighter than the surrounding ocean water because it doesn't contain salt. So it rises toward the surface, mixing the warm ocean water upward in the process. The warm water then rubs up against the bottom of the glacier, causing even more of the glacier to melt. This often leads to calving – ice cracking and breaking off into large ice chunks (icebergs) – at the front end, or terminus, of the glacier. The complicated shape of the sea floor surrounding Greenland influences how readily this warm water melt can occur. It provides a barrier in some areas – preventing the deep, warmer water from the Atlantic Ocean from reaching glacier fronts. However, the underwater terrain, much like the terrain above water, includes other features like deep canyons. The canyons cut into the continental shelf, allowing the Atlantic waters in. Glaciers sitting in these waters will melt faster than those where the warm water is blocked by underwater ridges or sills. Ice Loss in Antarctica In Antarctica, where similar surface and ocean melting processes occur, the topography and bedrock on which the ice sheet sits significantly influence the ice sheet's stability and its contribution to sea level rise. Researchers separate Antarctica into two regions based on the relationship between the ice and the bedrock beneath it. East Antarctica, the area east of the Transantarctic Mountains, is extremely high in elevation and has the thickest ice on the planet. The bedrock underneath the ice sheet is also mostly above sea level. These features help to keep the east side relatively stable. West Antarctica, on the other hand, is lower in elevation and most of the ice sheet there is thinner. Unlike the east, the ice sheet in West Antarctica sits on bedrock that is below sea level. "In West Antarctica, we have these glaciers resting on bedrock that is under water. Like in Greenland, there is a layer of warmer ocean water below the cold surface layer. So this warm water is able to flow onto the continental shelf, and then all the way underneath the ice shelves – the floating ice that extends from glaciers and the ice sheet,” said NASA Jet Propulsion Laboratory scientist Helene Seroussi. “The water melts the ice shelves from below, which can cause them to thin and break off." The visualization shows how ocean currents flow around and under Pine Island Glacier in Antarctica. As the water makes its way underneath the ice shelf, it erodes the ice shelf from the bottom causing it to become thinner. The visualization was produced using the "Estimating the Circulation and Climate of the Ocean" (ECCO) V3 ocean circulation model, the 100 meter "Reference Elevation Model of Antarctica" (REMA) surface elevation and the 450 meter bed topography and ice thickness BedMachine Antarctica V1 datasets. The surface is mapped with scenes from NASA's LandSat 8 satellite. Exaggeration factors of 4 and 15 – above and below sea level respectively – were used for clarity. Credit: NASA / Cindy Starr That matters because the ice shelves act like corks. They hold back the ice that is flowing from upstream, slowing its approach to the ocean where it raises sea level. When the ice shelves calve, the cork is essentially removed, allowing more inland ice to flow freely into the ocean. Furthermore, this leads to retreat of the grounding zone – the area where the ice separates from the bedrock and begins to float. "The grounding zone delineates floating ice, which is already accounted for in the sea level budget from grounded ice which is not accounted for in the budget," said ICESat-2 scientist Kelly Brunt of NASA's Goddard Space Flight Center and the University of Maryland. "Floating ice is like an ice cube floating in a glass. It doesn't overflow the glass when it melts. But when non-floating ice is added to the ocean, it's like adding more ice cubes to the glass which will cause the water level to rise." The bedrock in West Antarctica is also reverse sloping – meaning it is higher at the edges and gradually becomes deeper further inland. So each time the grounding zone retreats inland, thicker ice is exposed to the ocean water and the glacier or ice sheet becomes grounded in deeper water. This allows even more ice to flow from upstream into the ocean. "It's concerning in West Antarctica because as we push the grounding zones back, the downward, reverse slope means that there's really no backstop, nothing to interrupt this cycle of melting and retreat," said Brunt. "Our maps of the bedrock under the ice sheet are not as comprehensive as they are in Greenland, in part because Antarctica is far less accessible. Because of that, we really don't know if there are any little bumps or peaks down there that might help to slow the retreat." West Antarctic glaciers like Thwaites and Pine Island are already retreating faster than they were in the past. This is problematic because they provide a main pathway for ice from the West Antarctic Ice Sheet to enter the Amundsen Sea and raise sea levels. Overall, melting and ice loss have accelerated at both poles in recent years. The more we learn about the processes and interactions that cause it, some of which were discussed here, the better we'll be able to accurately and precisely predict sea level rise far into the future. News Media Contacts Ian J. O'Neill / Jane J. Lee Jet Propulsion Laboratory, Pasadena, Calif. 818-354-2649 / 818-354-0307 ian.j.oneill@jpl.nasa.gov / jane.j.lee@jpl.nasa.gov
  • Rising Waters
    Earth’s global sea levels are rising – and are doing so at an accelerating rate. Waters in the ocean are expanding as they absorb massive amounts of heat trapped by greenhouse gases in Earth’s atmosphere. Glaciers and ice sheets are adding hundreds of gigatons of meltwater into the oceans each year. The land surface along the coasts is also creeping up and down, affecting relative sea level rise. People are feeling the impacts, as seemingly small increments of sea level rise become big problems along coastlines worldwide. Global Mean Seal Level from 1993 to 2020 has been rising about 3.3 millimeters per year. The number is calculated by averaging sea surface height data from a series of satellites: TOPEX/Poseidon, Jason-1, OSTM/Jason-2 and Jason-3. The data record continues with the launch of Sentinel-6 Michael Freilich. Credit: NASA NASA Studies All Aspects of Sea Level Rise With satellites, airborne missions, shipboard measurements, and supercomputers, NASA has been investigating sea level rise for decades. Together with our international and interagency partners, we’re monitoring the causes of sea level rise with high accuracy and precision. Global sea level is rising approximately 0.13 inches (3.3 millimeters) a year. That’s 30% more than when NASA launched its first satellite mission to measure ocean heights in 1992. Sentinel-6 Michael Freilich was named in honor of Earth scientist Michael Freilich, who retired in 2019 as head of NASA’s Earth Science division, a position he held since 2006. Freilich’s career as an oceanographer spanned nearly four decades and integrated research on Earth’s oceans, leading satellite mission development, and helping to train and inspire the next generation of scientific leaders. His training was in ocean physics, but his vision leading NASA Earth Science encompassed the full spectrum of Earth’s dynamics. He passed away in 2020. Credit: NASA Humanity, not one agency, not one country, not one continent, but . . . humanity has been monitoring global sea level from space with exquisite accuracy for more than 28 years. - Michael Freilich, 1954-2020 This month, NASA is partnering with the European Space Agency, NOAA and EUMESTAT to launch the Sentinel-6 Michael Freilich satellite, which will continue 28 years of satellite-based ocean height measurements. The satellite was renamed in honor of the late director of NASA’s Earth Science Division, an oceanographer by training who recognized that a complex problem like sea level rise requires people with diverse backgrounds, from across the globe, to solve. Artist’s drawing of Sentinel-6 Michael Freilich. Credit: NASA/Jet Propulsion Laboratory In 2014, NASA created a Sea Level Change Science Team to bring together experts from across the agency and at other institutions that study different aspects of this multidisciplinary problem. Scientists studying glaciers, ice sheets, ocean physics, land movement and more are brought together to tackle what sea level rise looks like now – and what it will look like in the future. “We’re united by this big goal,” said Nadya Vinogradova Shiffer, the NASA program manager who oversees the team. “Sea level is impacted by these different factors that one discipline doesn’t cover – so we’ve got to bring in experts to approach it from all angles.” Four Impacts of Sea Level Rise Rising Sea Level: Meltwater from Ice About two-thirds of global sea level rise is due to meltwater from glaciers and ice sheets, the vast expanses of ice that cover Antarctica and Greenland. In Greenland, most of the ice loss stems from warming air temperatures that melt the surface of the ice sheet, as well as calving from the glaciers that empty into the sea. In Antarctica, however, year-round freezing temperatures mean that the surface of the interior ice sheet doesn’t melt. Instead, most of the ice is lost as warmer ocean temperatures join warm air temperatures to eat away at the floating ice shelves at the ends of glaciers in West Antarctica. This causes the glaciers to speed up, and more ice to flow – and melt – into the sea. NASA measures this change from space. With the Ice, Cloud and land Elevation Satellite 2, or ICESat-2, scientists can calculate the change in height of the ice sheets to within a fraction of an inch, allowing them to calculate how changing ice sheets are contributing to sea level rise. With the Gravity Recovery and Climate Experiment Follow-On satellites, or GRACE-FO, a partnership with the German Research Centre for Geosciences, scientists can calculate the mass of ice lost from these vast expanses across Greenland and Antarctica. The ice sheets alone contributed around 1.2 millimeters per year to sea level rise between 2002 and 2017, scientists calculated by comparing data from the GRACE and GRACE-FO satellites. Since 2006, an average of 318 gigatons of ice per year has melted from Greenland and Antarctica’s ice sheets, scientists calculated by comparing data from the first ICESat and ICESat-2. One gigaton is enough to cover New York City’s Central Park in ice 1,000 feet deep. Glaciers in places like Alaska, High Mountain Asia, South America and the Canadian Arctic are susceptible to warming air temperatures. Over the last decade, nearly all glaciers have been shrinking. Whether the glaciers empty directly into the ocean, or into rivers that eventually reach the sea, the meltwater from these smaller glaciers contributes about as much to sea level rise as the meltwater from massive ice sheets contributes. Rising Sea Level: Thermal Expansion Not only is more water flowing into the ocean from ice sheets and glaciers – the warmer water of the ocean is taking up more space, adding to sea level rise. The upper 2,300 feet (700 meters) of the ocean has been warming since the 1970s – and much of the extra heat generated by global warming is absorbed by the ocean. When water warms, individual molecules move around faster, expanding the volume that they take up. On a global scale, this causes about a third of the sea level rise that scientists have measured. Like all sea level change, thermal expansion varies across the oceans – some regions are more affected than others. Currents and winds move this newly warmed and expansive water around, and that warmer water influences the strengths and patterns of ocean currents. Instruments like the Argo floats from Scripps Institution of Oceanography in San Diego collect temperature and other data on the ocean waters. Complicating Sea Level: Ocean Circulation Sea level rise isn’t consistent across the globe. Some coastal areas see triple the average rate of rise while others don’t observe any changes, or can even see a drop in sea level. Ocean currents, the upwelling of cold water from the deep ocean, winds, movements of heat and freshwater, and Earth’s gravitational pull all play a role in moving water masses around. When water melts from Greenland, for example, the drop in mass decreases the gravitational pull from the ice sheet, causing water to slosh toward the shores of South America. Warmer waters can speed up currents, and even tilt the surface of the ocean – changes that will be measured by the upcoming Surface Water and Ocean Topography satellite mission, developed by NASA and international partners. Naturally occurring ocean climate cycles can also play a role in temporarily masking or enhancing the effects of climate change on sea level rise. During most of the time that satellites have been measuring global sea surface height, sea level rise along the West Coast of the United States has been lower than the global average due to extended cool phases of the Pacific Decadal Oscillation (PDO), a long-term cyclical pattern of climate variability in the Pacific Ocean that affects ocean and atmospheric conditions. The cool PDO phase pushed warm water away from the U.S. West Coast, suppressing sea level rise. But around 2010-2011, the PDO shifted to its warm phase, and scientists are now observing faster-than-average sea level rise for the region, which is expected to continue for at least the next five years and potentially much longer. Complicating Sea Level: Solid Earth Dynamics It’s not only water processes that play a role in global sea level rise – ground movements can play a significant role as well. On a continental scale, Earth’s crust is still recovering from the last ice age. 20,000 years ago, Canada, the northeast United States, Scandinavia and other regions were weighed down by ice sheets. As the ice sheets melted, and the weight on the continents eased, the land surface slowly rebounded. That rebounding process is still occurring and can even cause other places to drop – for example, Norfolk, Virginia is sinking due to rebounding further north. Rising sea levels can also be compounded by sinking land. The Mississippi River Delta, for example, is essentially drowning as sinking ground from resource extraction, sediment loading, and the weight of the built environment is combined with higher sea levels. NASA will be studying this case with a field campaign called Delta-X, designed to study how sediments are accumulating on the delta. Future Sea Level As scientists from a range of disciplines study the causes of sea level rise, their colleagues are also using advanced climate, ocean, and ice computer models to predict what sea level rise will look like in the future. A NASA-led study brought together scientists from across the globe to determine how meltwater from ice sheets will impact sea level rise by 2100. Other recent work has examined how ice loss in one region impacts cities around the globe, and how glaciers in High Mountain Asia will respond in the coming century due to a warming climate. The future of sea level rise is a fast-moving global problem, so scientists need the most comprehensive and accurate models possible. NASA’s Sea Level Change team is tasked with coming up with its own predictions for sea level rise on multiple time horizons, from decadal to centennial time scales, said lead Vinogradova Shiffer – a challenging task, given all the contributing and complicating factors. But the team is designed to approach the problem from all angles. “We’ve assembled a team of leading experts in the field, covering all the ground related to sea level rise, and we’re excited about finding the best answer to these questions,” she said. “You can’t not do it together." NASA's Sea Level Change Portal Education Resources Sea Level Data

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