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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  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Effects of atmospheric CO2 enrichment on net photosynthesis and dark respiration rates [link] Identifying key driving processes of major recent heat waves [link] Reassessing Southern Ocean air-sea … Continue reading →
  • Escape from model land
    by Judith Curry “Letting go of the phantastic mathematical objects and achievables of model- land can lead to more relevant information on the real world and thus better-informed decision- making.” – Erica Thompson and Lenny Smith The title and motivation … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Coupled modes of North Atlantic ocean-atmosphere variability and the onset of the Little Ice Age [link] Marine Ice Cliff Instability mitigated by slow removal of ice shelves … Continue reading →
  • Reflections on energy blogging
    by Planning Engineer Five years ago today I started guest blogging on Climate Etc., focusing on energy related issues. My initial goal was to share some insights in a more formal fashion on energy related issues being discussed in the … Continue reading →
  • Gregory et al 2019: Unsound claims about bias in climate feedback and climate sensitivity estimation
    By Nic Lewis The recently published open-access paper “How accurately can the climate sensitivity to CO2 be estimated from historical climate change?” by Gregory et al.[i] makes a number of assertions, many uncontentious but others in my view unjustified, misleading … Continue reading →
  • Climate ‘limits’ and timelines
    by Judith Curry Some thoughts in response to a query from a reporter. I received the following questions today from a reporter, related to climate change and ‘timelines.’   These questions are good topics for discussion. My answers are provided below … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Was Common ra glacier expansion in the Arctic Atlantic region triggered by unforced atmospheric cooling? [link] The amplitude and origin of sea level variability during the Pliocene … Continue reading →
  • Resplandy et al. Part 5: Final outcome
    By Nic Lewis The editors of Nature have retracted the Resplandy et al. paper. Readers may recall that last autumn I wrote several article critiquing the Resplandy et al. (2018) ocean heat uptake study in Nature, which was based on … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Indian Ocean warming can strengthen the Atlantic meridional overturning circulation [link] Indian ocean warming trend reduces Pacific warming response to anthropogenic greenhouse gases: an interbasin thermostat mechanism … Continue reading →
  • A philospher’s reflections on AGW denial
    by Dr. Paul Viminitz Of the things I care most about, AGW is near the bottom. But because, as George W. Bush put it, either you’re with us or you’re against them, I think I’d rather be interestingly wrong than … Continue reading →
  • Don’t overhype the link between climate change and hurricanes
    by Judith Curry Doing so erodes scientific credibility — and distracts from the urgent need to shore up our vulnerability to storms’ impacts. Here is the link to my op-ed in the National Review.  Full text below. n the aftermath … Continue reading →
  • ‘Alarmism enforcement’ on hurricanes and global warming
    by Judith Curry I used to be concerned about ‘consensus enforcement’ on the topic of climate change.  Now I am concerned about ‘alarmism enforcement.’ Ever since Hurricane Katrina in 2005, any hurricane causing catastrophic damage has been seized upon  by … Continue reading →
  • ENSO predictions based on solar activity
    by Javier By knowing or estimating where in the solar cycle we are we can get an estimate of the chances of a particular outcome even years ahead. El Niño Southern Oscillation (ENSO) is the main source of interannual tropical … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Several papers of fundamental importance: *Important new paper by Peter Minnett:  The response of the ocean thermal skin layer to variations in incident infrared radiation [link] *A … Continue reading →
  • Climate Change: What’s the Worst Case?
    by Judith Curry My new manuscript is now available. A link to my new paper ‘Climate Change: What’s the Worst Case?’ is provided here [worst case paper final (1)] A few words on the intended audience and motivation for writing … Continue reading →
  • Re-evaluating the manufacture of the climate consensus
    by Judith Curry A new book by Oppenheimer, Oreskes et al. entitled ‘Discerning Experts: The Practices of Scientific Assessment for Environmental Policy‘ makes a case against consensus seeking in climate science assessments. I have long railed against the consensus-seeking process … Continue reading →
  • The latest travesty in ‘consensus enforcement’
    The latest travesty in consensus ‘enforcement’, published by Nature. There is a new paper published in Nature, entitled Discrepancies in scientific authority and media visibility of climate change scientists and contrarians. . Abstract. We juxtapose 386 prominent contrarians with 386 … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. ‘modern climate sensitivity is relatively low in the context of the geological record, as a result of relatively weak feedbacks due to a relatively low CO2 baseline, … Continue reading →
  • Climate Change and Land: discussion thread
    by Judith Curry Discussion thread on the new IPCC Report on Climate Change and Land. The complete Report can be downloaded here [link]. I’m working on digesting all this, here are some articles that I’ve flagged on my twitter feed. … Continue reading →
  • Child prophets and proselytizers of climate catastrophe
    by Andy West The role of children in the culture of climate catastrophism 1.Serious scenarios for children: reality or culture? 1.1 Frightening our children: When do we find it acceptable to institutionally frighten children? While our first thought is perhaps … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Variability in decadal global temperature increases strongly with climate sensitivity [link] 1200 year reconstruction of temperature extremes in the northeastern Mediterannean region [link] Extreme heat years have … Continue reading →
  • Geothermal ocean warming discussion thread
    by Judith Curry “The atmosphere bias of climate science makes it impossible for them to see geological forces and therefore, impossible for them to understand the earth’s climate.” – Thongchai When conducting the literature survey for my report on sea … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Reviews of Geophysics:  Observing and modeling ice sheet surface mass balance [link] Effects of variability in the Atlantic Ocean circulation [link] “Global and Regional Increase of Precipitation … Continue reading →
  • Climate scientists’ pre-traumatic stress syndrome
    by Judith Curry It’s getting worse. About 5 years ago, I wrote two blog posts on climate scientists’ pre-traumatic stress syndrome: Pre-traumatic stress syndrome: climate trauma survival trips Pre-traumatic stress syndrome: climate scientists speak out Mother Jones has a new … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. (http://bit.ly/2NfdWba ) 2,000 years of North Atlantic climate change and considers how ocean circulation may have contributed to historical climate shifts. More from  http://bit.ly/2Lkquvx . New HadSST4.0 data set … Continue reading →
  • Truth(?) in testimony and convincing policy makers
    by Judith Curry Some reflections, stimulated by yesterday’s Congressional Hearing, on the different strategies of presenting Congressional testimony. Yesterday’s Hearing provided an ‘interesting’ contrast in approaches to presenting testimony, when comparing my testimony with Michael Mann’s. What are the purposes … Continue reading →
  • Hearing on climate change and natural disasters: Today
    by Judith Curry The House Oversight and Reform Environmental Subcommittee in a Hearing on Recovery, Resilience and Readiness – Contending with Natural Disasters in the Wake of Climate Change begins at 2 pm EDT. The announcement for the Hearing is posted … Continue reading →
  • Hearing on climate change & extreme weather
    by Judith Curry On Tuesday June 25, I will be testifying before the House Oversight and Reform Environmental Subcommittee in a Hearing on Recovery, Resilience and Readiness – Contending with Natural Disasters in the Wake of Climate Change. The announcement … Continue reading →
  • Climate science’s ‘masking bias’ problem
    by Judith Curry How valid conclusions often lay hidden within research reports, masked by plausible but unjustified conclusions reached in those reports.  And how the IPCC institutionalizes such masking errors in climate science. In the previous post, we discussed the … Continue reading →
  • Climate scientists’ motivated reasoning
    by Judith Curry Insights into the motivated reasoning of climate scientists, including my own efforts to sort out my own biases and motivated reasoning following publication of the Webster et al. (2005) paper A recent twitter thread by Moshe Hoffman … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Runs that reduce sea ice also result in a significant decrease in the frequency and magnitude of extreme warm and cold temperature anomalies”. Reduction in northern mid-latitude … Continue reading →
  • Extremes
    by Judith Curry Politics versus science in attributing extreme weather events to manmade global warming. If you follow me on twitter, you may have noticed that I was scheduled to testify before the House Oversight and Reform Committee on Jun … Continue reading →
  • 2019 Atlantic hurricane forecast
    by Judith Curry and Jim Johnstone CFAN predicts an active North Atlantic hurricane season season. The Atlantic hurricane has begun.  We are off to an early start with one wimpy subtropical storm that lasted less than a day, and a … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. QBO primer [link] Periodicity disruption of a model quasibiennial oscillation of equatorial winds https://journals.aps.org/prl/accepted/2d072Y42Lef16d5ef7d47192a2a4f7c1d27a126c5 … Influence of the QBO on MJO prediction skill in the subseasonal-to-seasonal prediction models … Continue reading →
  • Hearing on the Biodiversity Report
    by Judith Curry The House Natural Resources Committee Subcommittee on Water, Oceans and Wildlife is holding a Hearing today on Responding to the Global Assessment Report of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. The link to the … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Validation of atmospheric reanalysis data sets in the Arctic. [link] ENSO Normals: A New U.S. Climate Normals Product Conditioned by ENSO Phase and Intensity and Accounting for … Continue reading →
  • Climate’s uncertainty principle
    by Garth Paltridge On the costs and benefits of climate action. Whether we should do anything now to limit our impact on future climate boils down to an assessment of a relevant cost-benefit ratio. That is, we need to put … Continue reading →
  • Rebelling against the Extinction Rebellion
    by Larry Kummer The Extinction Rebellion and the Green New Deal arouse fears of extinction for other species, and humanity. Only the complicit silence of climate scientists makes this possible. Compare the alarmists’ claims with what scientists said in the … Continue reading →
  • Beto’s climate action plan
    by Judith Curry Beto O’Rourke’s Climate Change Plan deserves a close look. For those of you not in the U.S., Beto O’Rourke is one of the 20+ candidates vying for the Democratic Party nomination for the Presidential election in 2020. … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Uncertainty quantification of the multi-centennial response of the Antarctic ice sheet to climate change  https://buff.ly/2IFU26o  “India’s Depleting Groundwater: When Science Meets Policy” https://doi.org/10.1002/app5.269 Regime shift of global … Continue reading →
  • Energy Security and Grid Resilience
    by Judith Curry Diversifying and securing energy supplies nationally and locally. Since we’ve moved to Nevada and have been integrating into the local community, the most interesting thing we’ve come across is the National Security Forum of Northern Nevada (NSF). … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past few weeks. Why did the trend of #Arctic #sea #ice loss accelerate after about 2000?” Meehl et al. (2018) offer an explanation. https://doi.org/10.1029/2018GL079989 … Antarctica’s iceberg graveyard could reveal … Continue reading →
  • 2019 ENSO forecast
    by Judith Curry and Jim Johnstone CFAN’s 2019 ENSO forecast is for a transition away from El Niño conditions as the summer progresses. The forecast for Sept-Oct-Nov 2019 calls for 60% probability of ENSO neutral conditions, with 40% probability of … Continue reading →
  • What’s the worst case? Climate sensitivity
    by Judith Curry Are values of equilibrium climate sensitivity > 4.5 C plausible? For background, see these previous posts on climate sensitivity [link] Here are some possibilistic arguments related to climate sensitivity.  I don’t think the ECS example is the … Continue reading →
  • Why climate predictions are so difficult
    by Judith Curry An insightful interview with Bjorn Stevens. Frank Bosse provided this Google translation of an interview published in Der Spiegel  -Print-Issue 13/2019, p. 99-101.   March 22, 2019 Excerpts provided below, with some minor editing of the translation. begin … Continue reading →
  • What’s the worst case? Emissions/concentration scenarios
    by Judith Curry Is the RCP8.5 scenario plausible? This post is Part II in the possibility series (for an explanation of the possibilistic approach, see previous post link).  This paper also follows up on a recent series of posts about … Continue reading →
  • What’s the worst case? A possibilistic approach
    by Judith Curry Are all of the ‘worst-case’ climate scenarios and outcomes described in assessment reports, journal publications and the media plausible? Are some of these outcomes impossible? On the other hand, are there unexplored worst-case scenarios that we have … Continue reading →
  • Why I don’t ‘believe’ in ‘science’
    by Judith Curry ” ‘I believe in science’ is an homage given to science by people who generally don’t understand much about it. Science is used here not to describe specific methods or theories, but to provide a badge of … Continue reading →
  • Four fronts for climate policy
    by Judith Curry “For decades, scientists and policymakers have framed the climate-policy debate in a simple way: scientists analyse long-term goals, and policymakers pretend to honour them. Those days are over. Serious climate policy must focus more on the near-term … Continue reading →
  • Week in review – science edition
    by Judith Curry A few things that caught my eye this past week. Background paper on detection and attribution in CMIP6 [link] What’s missing from Antarctic ice sheet loss predictions? [link] Vegetation and climate change in the Pro-Namib and Namib … Continue reading →

NASA GLOBAL CLIMATE CHANGE NEWS

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  • Examining the Viability of Planting Trees to Help Mitigate Climate Change
    It’s an intriguing premise: what if we could reduce the severity of global climate change by planting hundreds of billions of trees to remove excess carbon from our atmosphere? A recent study published in the journal Science sought to provide answers by estimating the global potential of restoring forested lands as a possible strategy for mitigating climate change. The international research team, led by Jean-Francois Bastin of ETH-Zurich in Switzerland, used direct measurements of forest cover around the world to create a model for estimating Earth’s forest restoration potential. They found Earth’s ecosystems could support another 900 million hectares (2.2 billion acres) of forests, 25 percent more forested area than we have now. By planting more than a half trillion trees, the authors say, we could capture about 205 gigatons of carbon (a gigaton is 1 billion metric tons), reducing atmospheric carbon by about 25 percent. That’s enough to negate about 20 years of human-produced carbon emissions at the current rate, or about half of all carbon emitted by humans since 1960. The study attracted worldwide attention, as well as some criticism within the science community. Is the concept of planting trees to help combat climate change really going out on a limb, so to speak, or might it take root? Sassan Saatchi, a senior scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, believes it has some merit. But while he says there’s potential for using reforestation as a climate mitigation tool, he cautions there are many factors to consider and that planting trees will never be a substitute for decreasing fossil fuel emissions. “I feel there’s a strong possibility a significant portion of these lands can be reforested to their original forest cover,” said Saatchi, an expert in global forest carbon stocks and dynamics. “It’s definitely not a solution by itself to addressing current climate change. To do that, we need to reduce human emissions of greenhouse gases. But it could still have some partial impact on our ability to reduce climate change.” A multi-country-led effort called the African Forest Landscape Restoration Initiative (AFR100) is working to reforest 100 million hectares of land in Africa by 2030. Credit: Andrea Borgarello for TerrAfrica/World Bank Saatchi says the study establishes a reasonable estimate of global forest restoration potential and addresses the issue more directly than previous work. The researchers used new satellite-based land cover and land use maps, along with other climate and soil data and advanced techniques to arrive at their results. He says their conclusions on tree restoration aren’t that different from the recommendations made by the Intergovernmental Panel on Climate Change in 2018, which suggested that 950 million hectares (2.3 billion acres) of new forests could help limit the increase in global average temperature to 1.5-degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels by 2050. However, he says, “the devil is in the details.” Many Unanswered Questions Before a global forest restoration effort is undertaken, Saatchi says, numerous questions must first be addressed to assess the concept’s feasibility, scientific soundness, cost-efficiency, risks and other considerations. “We need to understand not only whether it’s possible to do such a thing, but whether we should do it,” he says. “The paper has sparked a healthy debate in the science community, which has now come forward to begin to address issues that the paper did not,” he said. “The science community has been looking at these questions to some extent for a long time, but there’s more urgency to address them now, since we no longer have the same climate conditions we had 50 or 100 years ago, when humans began massive deforestation for agriculture and human settlements. Since then, Earth’s population and land use have increased drastically. In some parts of the Northern Hemisphere, countries have been able to save more forests, but other areas, such as the tropics, have seen massive deforestations because of the need to feed larger populations.” Areas of degraded rainforest in the Democratic Republic of Congo. Credit: NASA/JPL-Caltech/Sassan Saatchi Saatchi outlined a few of the many questions scientists and others will want to investigate. For example, how realistic are the study’s estimates of how much carbon can be sequestered through reforestation? How long will this approach take to make a dent in atmospheric carbon concentrations? Can grasslands and savanna ecosystems sustain increased tree cover? How might converting non-forest land to forests compete with food production? How much time, money and resources will it take to implement a global forest restoration of this magnitude? How do the costs of adopting such a climate mitigation strategy stack up against its potential benefits? How much carbon would be released to the atmosphere by restoring forests? How will global climate models respond to a massive forest restoration? Will an Earth with a billion hectares of new forests actually be cooler? Fire suppression tactics have allowed this forest at the edge of a savanna in Gabon, Central Africa, to regenerate naturally. Credit: NASA/JPL-Caltech/Sassan Saatchi “Planting a billion hectares of trees won’t be easy,” he said. “It would require a massive undertaking. If we follow the paper’s recommendations, reforesting an area the size of the United States and Canada combined (1 to 2 billion hectares) could take between one and two thousand years, assuming we plant a million hectares a year and that each hectare contains at least 50 to 100 trees to create an appropriate treetop canopy cover.” Even once the trees are planted, says Saatchi, it will take them about a century to reach maturity. Most forests in the United States are less than 100 years old because they are recycled constantly. Trees in tropical regions take a little bit longer to reach maturity, but sequester carbon much faster. We know it will take time for new forests to absorb atmospheric carbon.” Saatchi says scientists will want to do a comprehensive evaluation of all potential effects a mass reforestation may have on Earth’s climate and the global carbon cycle. Currently, Earth’s forests and soil absorb about 30 percent of atmospheric carbon emissions, partially through forest productivity and restoration. While deforestation has occurred throughout human history, the practice has increased dramatically in the past 50 years. According to the United Nations’ Food and Agriculture Organization, about 7.3 million hectares (18 million acres) of forest are lost every year, and roughly half of Earth’s tropical forests have already been cleared. In the continental United States, an estimate from the University of Michigan found that 90 percent of indigenous forests have been removed since 1600. Over time, the ocean and land have continued to absorb about half of all carbon dioxide emissions, even as those emissions have risen dramatically in recent decades. It remains unclear if carbon absorption will continue at this rate. Credit: NASA/JPL-Caltech Degraded landscapes in Colombia’s Choco region. Credit: NASA/JPL-Caltech/Sassan Saatchi As deforestation has ramped up, Earth’s climate has changed significantly. Warmer, more adverse climate conditions are creating more difficult growing conditions for forest ecosystems. Key questions scientists will need to address are how global reforestation might affect Earth’s surface albedo (reflectivity) and evapotranspiration. In the near term and locally, says Saatchi, forest restoration may actually have a warming effect. As the trees mature, the new forest canopy cover would presumably make Earth’s surface albedo darker, particularly in the Northern Hemisphere during periods of snow cover, causing it to absorb more heat. Increasing forest cover, particularly in the tropics, will increase evapotranspiration, causing a cooling effect. With Earth already warming significantly due to greenhouse gas emissions, will forest reforestation on a global scale have a net warming or cooling effect on our planet, and will the benefits of reforested areas absorbing more carbon outweigh their increased heat absorption? These effects may vary geographically from tropical to boreal regions and may depend largely on water and light availability. In addition, how might these changes impact climate change patterns? “Recent Landsat satellite-based analyses show that close to 400 million hectares (988 million acres) of forests have been disturbed in this century alone (2000-2017), either by human activities or through droughts and fires – that’s almost 50 percent of the area recommended for reforestation by the authors of the new study,” he said. Some of these areas have gone back to being forests, but a large amount of these degraded forests located in tropical and subtropical regions are suitable targets for restoration. Map of global tree loss/tree gain since the early 1980s derived from NASA Landsat and NOAA AVHRR optical imagery, revised by Sassan Saatchi from Song et al., 2016. Credit: NASA/JPL-Caltech/Sassan Saatchi Another science question concerns biodiversity. Will ecosystems in reforested areas revert to their previous conditions and maintain their ability to sequester carbon? While ecosystems that existed before areas were deforested may have been highly diverse, reforesting them with only a single type of species (known as monocultures), might result in ecosystems that won’t function as efficiently as they did before – in other words, they may not grow the same or stay as healthy over time. Saatchi says each region of the world will need to address this question for itself. But restoring a region’s original biodiversity or its natural forests may not be easy. For example, the region’s soil health may have changed. Yet another concern is something Saatchi calls climate connectivity. When ecosystems become too fragmented, they begin losing their natural functions. “In Earth’s tropical regions, a combination of deforestation and climate conditions may have actually changed the system so much that climate connectivity is reduced,” he says. “Once this connectivity is lost, it becomes much more difficult for a reforested area to have its species range and diversity, and the same efficiency to absorb atmospheric carbon.” Saatchi says scientists are already studying some of these questions. He believes that by the end of the next decade, better results from satellite observations and modeling will likely enable us to determine whether a global forest reforestation will produce the carbon and climate benefits suggested by the new study, and whether it should be undertaken. In the meantime, stopping further deforestation and restoring these areas to their original forest cover of 50 years ago may be the most effective mitigation strategy. Looking to Space for Answers Saatchi says a number of current and planned satellite missions from NASA and other space agencies can make valuable contributions to these research efforts: Instruments on NASA satellites, such as the Clouds and the Earth’s Radiant Energy System (CERES) instrument on NASA’s Terra satellite, continuously monitor the energy balance of Earth’s land surfaces, measuring their albedo, a key climate parameter that would be impacted by reforestation. Map created from data from the CERES instrument on NASA’s Terra satellite, showing how the reflectivity of Earth—the amount of sunlight reflected back into space—changed between March 1, 2000, and December 31, 2011. This global picture of reflectivity (also called albedo) appears to be a muddle, with different areas reflecting more or less sunlight over the 12-year record. Shades of blue mark areas that reflected more sunlight over time (increasing albedo), and orange areas denote less reflection (lower albedo). Credit: NASA's Earth Observatory NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on the agency’s Aqua and Terra satellites provide a suite of measurements on global forest cover change, fire and forest carbon cycling function. NASA’s ECOsystem Spaceborne Thermal Radiometer Experiment (ECOSTRESS) aboard the International Space Station, launched last year, measures evapotranspiration and stress on ecosystems, providing valuable information on how Earth’s energy, water and carbon cycles interact in ecosystems in a warming climate. NASA's ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) imaged the stress on Costa Rican vegetation caused by a massive regional drought that led the Central American nation's government to declare a state of emergency. The image was acquired on February 15, 2019, then processed to generate the evaporative stress image. Credit: NASA/JPL-Caltech NASA scientists conduct research to map the functional traits of ecosystems. Models, combined with satellite observations, can examine whether ecosystems will absorb more carbon if we plant new trees. A new NASA mission in development for launch in the next decade called Surface Biology and Geology (SBG) would give scientists a global view of the functional traits and diversity of ecosystems and their efficiency in absorbing carbon, water and energy. Other space agencies also plan to make similar measurements. NASA’s recently launched Global Ecosystem Dynamics Investigation (GEDI) aboard the space station is conducting high-resolution laser ranging of Earth’s forests and topography to study how deforestation has contributed to atmospheric carbon dioxide concentrations, how much carbon forests will absorb in the future, and how degradation of habitats will affect global biodiversity. NASA’s Global Ecosystem Dynamics Investigation (GEDI) mission created this image of a South Carolina woodland. Darker green colors show where the leaves and branches are denser, while the lighter areas show where the canopy is less dense. Credit: Joshua Stevens / NASA Earth Observatory, Bryan Blair / NASA Goddard Space Flight Center, Michelle Hofton and Ralph Dubayah / University of Maryland The NASA-ISRO Synthetic Aperture Radar (NISAR) mission, a dedicated U.S./Indian interferometric synthetic aperture radar (InSAR) mission scheduled to launch in 2022, will be able to measure the woody plants and forests that make up 80 percent of Earth’s living terrestrial biomass. NISAR’s global, detailed maps of above-ground woody biomass density are expected to cut in half current uncertainties in estimates of carbon emissions resulting from land use changes. The European Space Agency’s BIOMASS mission, launching in the early 2020s, will map the global distribution of above-ground biomass in forests to reduce uncertainties in estimates of carbon stocks and fluxes in the terrestrial biosphere, such as those linked to changes in land use, forest degradation and forest regrowth. “With these new missions, we should be able to monitor how every patch of forest around the world is absorbing carbon, and how carbon absorption is changing, on a monthly and annual basis,” said Saatchi. Seeing the Forests for the Trees: The Big Picture Saatchi says the study’s results can help address policy-relevant questions. In accordance with the Paris Agreement, after 2020, the global community has agreed to major emission reduction programs. Reforestation can complement these emission reduction strategies. “With the Paris Agreement, governments around the world committed to reduce emissions by adopting low-carbon pathways in accordance with nationally determined contributions,” he said. “As a result, it’s become more urgent than ever to have realistic estimates of each country’s capacity to increase its forest cover and health. While it’s likely the burden of restoring forests will fall primarily on the shoulders of the world’s large and economically-developed countries, the developing world can also contribute by reducing land use change and deforestation.” He adds governments will need to decide which land areas to target first and which will have the least negative economic impacts to both society and individual communities, such as indigenous populations. A Baka woman in central Gabon makes products from non-timber forest materials. Without forest conservation and restoration, indigenous forest people will be forced to re-establish themselves outside of forest areas. Credit: NASA/JPL-Caltech/Sassan Saatchi If it’s determined that a global reforestation effort can be successful, will the world’s governments have the will to do it? Saatchi pointed to some recent examples that show what might be possible. Over the past 15 years or so, China has planted millions of trees and created millions of hectares of new forest cover, much of it in areas with marginal agricultural potential. “China’s land use policy increased forest cover in southern China between 10 and 20 percent, turning these areas into intense managed forests,” he said. “As a result, they created close to a carbon sink (an area that stores carbon) in their forests, almost doubling their carbon uptake. The effort has offset 20 percent of China’s annual fossil fuel emissions, and since 2012 that percentage has increased to 33 percent. So that’s a success story.” Managed activities to increase the carbon sequestration of forests have also taken place in other parts of the Northern Hemisphere, including the United States, Canada, Europe and Russia, he says. He believes it’s possible to increase them even further and to extend the area or the capacity of these forests to sequester more carbon. In fact, he says, some foresters have been doing so for decades. “U.S. forests have actually been a net sink for carbon for many decades,” he says. “A paper published a couple of years ago showed that reforestation could reduce U.S. annual carbon emissions from all sources by 10 to 15 percent. Imagine if we do that? It’s possible. We just need to study the cost-to-benefit ratio – is it economically feasible to plant those trees compared to how much carbon they would offset?” The U.S. Forest Service is restoring this longleaf pine forest in Alabama. Credit: NASA/JPL-Caltech/Sassan Saatchi Another region Saatchi says is low-hanging fruit in terms of its potential to extend global tree cover is the Amazon, where large wildfires have made headlines recently. Between the 1970’s and 2010, 20 percent of the Amazon basin was deforested for land use activities — more than 100 million hectares of trees. But prior to last year, Brazil had significantly reduced deforestation for nearly a decade. “Restoring these Amazonian forests, if possible, would certainly absorb more carbon from the atmosphere,” he said. The Amazon rainforest near Manaus, Brazil. Fragmented landscapes in Earth’s humid tropics are suitable locations for restoration of native forests. Credit: Neil Palmer, Flickr Creative Commons / CC BY-NC-SA 4.0 Ultimately, should a global reforestation effort be deemed feasible, the biggest question may be whether it will be in time to make a difference for climate change. Saatchi is hopeful. “We know business as usual will be disastrous,” he said. “We’ve already identified some solutions for reducing carbon emissions in parts of our society, such as in transportation and agriculture, and we’re working on ways to transform our energy consumption. So why not restore our ecosystem as well? Half of what comes out of car tailpipes stays in the atmosphere; the rest gets absorbed by the ecosystem. That’s a huge absorptive capability that must be saved. “Maybe we’ll find we don’t need to plant a billion hectares of trees,” he continued. “Perhaps we can restore existing, degraded ecosystems to their natural state, especially in the tropics, and invest in maintaining their diversity and services. But I believe a global reforestation effort can have a gradual climate mitigation impact. What happens to Earth 100 years from now depends on the choices we make today.”
  • A Third of California Methane Traced to a Few Super-Emitters
    NASA scientists are helping California create a detailed, statewide inventory of methane point sources — highly concentrated methane releases from single sources — using a specialized airborne sensor. The new data, published this week in the journal Nature, can be used to target actions to reduce emissions of this potent greenhouse gas. Like carbon dioxide, methane traps heat in the atmosphere, but it does so more efficiently and for a shorter period of time. Scientists estimate that most methane emissions in California are driven by industrial facilities, such as oil and gas fields, large dairies and landfills. To help reduce methane's impact on climate, the state has made cutting human-caused emissions a priority. But in order to cut these hard-to-detect emissions, they have to be measured and the sources identified. NASA, through partnerships with the California Air Resources Board (CARB) and the California Energy Commission, set out to do just that. Over a two-year period, a research team at NASA's Jet Propulsion Laboratory in Pasadena, California, flew a plane equipped with the Airborne Visible InfraRed Imaging Spectrometer - Next Generation (AVIRIS-NG) instrument over nearly 300,000 facilities and infrastructure components in those sectors. The instrument can detect plumes of methane in great detail. Each pixel covers an area of about 10 feet (3 meters) across, which allows scientists to see even small plumes that often go undetected. The team identified more than 550 individual point sources emitting plumes of highly concentrated methane. Ten percent of these sources, considered super-emitters, contributed the majority of the emissions detected. The team estimates that statewide, super-emitters are responsible for about a third of California's total methane budget. Emissions data like this can help facility operators identify and correct problems — and in turn, bring California closer to its emissions goals. For example, of the 270 surveyed landfills, only 30 were observed to emit large plumes of methane. However, those 30 were responsible for 40 percent of the total point-source emissions detected during the survey. This type of data could help these facilities to identify possible leaks or malfunctions in their gas-capture systems. "These findings illustrate the importance of monitoring point sources across multiple sectors [of the economy] and broad regions, both for improved understanding of methane budgets and to support emission mitigation efforts," said the lead scientist on the study, Riley Duren, who conducted the work for NASA's Jet Propulsion Laboratory. Initial results have been shared with facility operators in California to make them aware of the need to improve their methane-leak detection processes and to institute better controls on methane emissions. Results will also be used to help state and local agencies and businesses prioritize investments in methane-emission mitigation. Although the survey provides a detailed map of methane emissions for the areas observed in the state, researchers caution that this was the first attempt to estimate emissions for individual methane sources from a large population distributed across such an extensive area over multiple years. Additionally, this survey was designed to detect highly concentrated releases of methane from a single component or piece of industrial equipment, such as an oil well. The survey excluded non-point sources, such as small natural gas leaks from millions of homes, because even though they may have a collective impact on atmospheric methane levels, their individual emissions are below the detection levels of this method. The survey builds on a decade of cooperation between NASA, CARB and the California Energy Commission to support the state's ambitious climate change mitigation program, specifically on the study of air pollution impacts from the oil and gas sector. "This new remote-sensing technology addresses the continuing need for detailed, high-quality data about methane," said California Air Resources Board Chair Mary D. Nichols. "It will help us and the Energy Commission develop the best strategies for capturing this highly potent greenhouse gas." The final report of the California Methane Survey will be available in the fall. The map and data from this survey can be viewed here: http://methane.jpl.nasa.gov/ News Media Contact Arielle Samuelson Jet Propulsion Laboratory, Pasadena, Calif. 818-354-0307 arielle.a.samuelson@jpl.nasa.gov
  • Drought-Stressed Forest Fueled Amazon Fires
    if (typeof captions == 'undefined'){ var captions = []; } captions.push("NASA's ECOSTRESS sensor measured the stress levels of plants when it passed over the Peruvian Amazon rainforest on Aug. 7, 2019. The map reveals that the fires were concentrated in areas of water-stressed plants (brown). The pattern points to how plant health can impact the spread of fires. Credit: NASA/JPL-Caltech/Earth Observatory › Full image and caption") captions.push("This satellite image, taken by NASA's Earth-observing Terra satellite on Aug. 18, 2019, shows the ECOSTRESS study area in the Amazon Basin and smoke from active fires in the rainforest. Image Credit: NASA/JPL-Caltech/Earth Observatory › Larger view") $(document).ready(function(){ var type = "news"; var slider = new MasterSlider(); // adds Arrows navigation control to the slider. slider.control('bullets', {autohide: false}); slider.control('arrows'); homepage_slider_options = { width: $(window).width(), // slider standard width height: 400, // slider standard height layout: "autofill", space:5, fullwidth: true, autoHeight: false, //will expand to height of image autoplay: false, speed: 20, loop: true, instantStartLayers: true //disable to allow for layer transitions }; slider.setup('masterslider_9238' , homepage_slider_options); if (type == "news"){ slider.api.addEventListener(MSSliderEvent.CHANGE_START , function(){ $('.slider_caption').html(captions[slider.api.index()]); }); } }); A new satellite-based map of a section of the Amazon Basin reveals that at least some of the massive fires burning there this past summer were concentrated in water-stressed areas of the rainforest. The stressed plants released measurably less water vapor into the air than unstressed plants; in other words, they were struggling to stay cool and conserve water, leaving them more vulnerable to the fires. The fires in the Amazon Basin, which continue to burn into November, are mainly the result of such human activities as land clearing and deforestation. The pattern — spotted from space by NASA's ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) — points to how water-stressed plants can impact the spread of fires. The data may one day help NASA's Earth-observing missions predict the path of future forest or brush fires like those currently raging in California. The primary mission of ECOSTRESS, an instrument that measures thermal infrared energy emitted from the land surface, is to provide insight into plants' health by taking their temperature. To keep cool, plants "sweat" by releasing water vapor through their pores, a process called evapotranspiration. After multiple orbits, ECOSTRESS is able to measure how much plants transpire and track their response to climate change. In August, fires spread over large swaths of the Amazon Basin. ECOSTRESS captured the first image of the Amazon rainforest in Peru before the fires began, on Aug. 7. It shows a surface temperature map revealing water-stressed and non-stressed forest (shown in brown and blue, respectively). The fire icons represent fires imaged by NASA's Terra satellite between Aug. 19 and 26. The fires are limited primarily to areas of water-stressed plants that transpired the least. The second image, taken by the Terra satellite on Aug. 18, shows the ECOSTRESS study area and smoke from active fires in the rainforest. The image also reveals how certain parts of the forest were more resilient, seeming to protect themselves from burning. Plants in these areas were cooler — in other words, they released more water vapor from their leaves — than plants in the burn zones, though mission scientists don't know whether that's a coincidence or a direct causal relationship. The water-stressed areas of the forest look as green and healthy as these cooler areas, making them invisible except to a radiometer that can measure thermal infrared energy from the surface. "To the naked eye, the fires appear randomly distributed throughout the forest," said Josh Fisher, ECOSTRESS science lead at NASA's Jet Propulsion Laboratory in Pasadena, California. "But, if you overlay the ECOSTRESS data, you can see that the fires are mainly confined within the highly water-stressed areas. The fires avoided the low-stress areas where the forest appears to have access to more water." It's still a mystery why some plants become stressed while other plants don't, though scientists believe it's dependent on factors like the species of plant or amount of water in the soil. The data from ECOSTRESS will help answer questions about which plants will thrive in their changing environments and could also be used to help with decisions related to water management and agricultural irrigation. JPL built and manages the ECOSTRESS mission for the Earth Science Division in the Science Mission Directorate at NASA Headquarters in Washington. ECOSTRESS is an Earth Venture Instrument mission; this program is managed by NASA's Earth System Science Pathfinder program at NASA's Langley Research Center in Hampton, Virginia. More information about ECOSTRESS is available here: https://ecostress.jpl.nasa.gov News Media Contact Arielle Samuelson Jet Propulsion Laboratory, Pasadena, Calif. 818-354-0307 arielle.a.samuelson@jpl.nasa.gov
  • Human Activities Are Drying Out the Amazon: NASA Study
    A new NASA study shows that over the last 20 years, the atmosphere above the Amazon rainforest has been drying out, increasing the demand for water and leaving ecosystems vulnerable to fires and drought. It also shows that this increase in dryness is primarily the result of human activities. Scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, analyzed decades of ground and satellite data over the Amazon rainforest to track both how much moisture was in the atmosphere and how much moisture was needed to maintain the rainforest system. "We observed that in the last two decades, there has been a significant increase in dryness in the atmosphere as well as in the atmospheric demand for water above the rainforest," said JPL's Armineh Barkhordarian, lead author of the study. "In comparing this trend to data from models that estimate climate variability over thousands of years, we determined that the change in atmospheric aridity is well beyond what would be expected from natural climate variability." The image shows the decline of moisture in the air over the Amazon rainforest, particularly across the south and southeastern Amazon, during the dry season months - August through October - from 1987 to 2016. The measurements are shown in millibars. Credit: NASA/JPL-Caltech, NASA Earth Observatory Larger view So if it's not natural, what's causing it? Barkhordarian said that elevated greenhouse gas levels are responsible for approximately half of the increased aridity. The rest is the result of ongoing human activity, most significantly, the burning of forests to clear land for agriculture and grazing. The combination of these activities is causing the Amazon's climate to warm. When a forest burns, it releases particles called aerosols into the atmosphere - among them, black carbon, commonly referred to as soot. While bright-colored or translucent aerosols reflect radiation, darker aerosols absorb it. When the black carbon absorbs heat from the sun, it causes the atmosphere to warm; it can also interfere with cloud formation and, consequently, rainfall. Why It Matters The Amazon is the largest rainforest on Earth. When healthy, it absorbs billions of tons of carbon dioxide (CO2) a year through photosynthesis - the process plants use to convert CO2, energy and water into food. By removing CO2 from the atmosphere, the Amazon helps to keep temperatures down and regulate climate. But it's a delicate system that's highly sensitive to drying and warming trends. Trees and plants need water for photosynthesis and to cool themselves down when they get too warm. They pull in water from the soil through their roots and release water vapor through pores on their leaves into the atmosphere, where it cools the air and eventually rises to form clouds. The clouds produce rain that replenishes the water in the soil, allowing the cycle to continue. Rainforests generate as much as 80 percent of their own rain, especially during the dry season. But when this cycle is disrupted by an increase in dry air, for instance, a new cycle is set into motion - one with significant implications, particularly in the southeastern Amazon, where trees can experience more than four to five months of dry season. "It's a matter of supply and demand. With the increase in temperature and drying of the air above the trees, the trees need to transpire to cool themselves and to add more water vapor into the atmosphere. But the soil doesn't have extra water for the trees to pull in," said JPL's Sassan Saatchi, co-author of the study. "Our study shows that the demand is increasing, the supply is decreasing and if this continues, the forest may no longer be able to sustain itself." Scientists observed that the most significant and systematic drying of the atmosphere is in the southeast region, where the bulk of deforestation and agricultural expansion is happening. But they also found episodic drying in the northwest Amazon, an area that typically has no dry season. Normally always wet, the northwest has suffered severe droughts over the past two decades, a further indication of the entire forest's vulnerability to increasing temperatures and dry air. If this trend continues over the long term and the rainforest reaches the point where it can no longer function properly, many of the trees and the species that live within the rainforest ecosystem may not be able to survive. As the trees die, particularly the larger and older ones, they release CO2 into the atmosphere; and the fewer trees there are, the less CO2 the Amazon region would be able to absorb - meaning we'd essentially lose an important element of climate regulation. The study, "A Recent Systematic Increase in Vapor Pressure Deficit Over Tropical South America," was published in October in Scientific Reports. The science team used data from NASA's Atmospheric Infrared Sounder (AIRS) instrument aboard the Terra satellite. More information on AIRS can be found here: https://airs.jpl.nasa.gov/ News Media Contact Arielle Samuelson Jet Propulsion Laboratory, Pasadena, Calif. 818-354-0307 arielle.a.samuelson@jpl.nasa.gov
  • The Atmosphere: Keeping a Weather Eye on Earth's Climate Instabilities
    Part Five “I wouldn’t describe Earth’s atmosphere as fragile so much as I’d say our climate system is unstable,” said atmospheric scientist Eric Fetzer of NASA’s Jet Propulsion Laboratory in Pasadena, California. “Climate is being changed by the addition of greenhouse gases to the atmosphere.” Fetzer said humanity has pushed climate instability well away from where it has been for many millennia. “We’ve had 8,000 years of pretty much the same climate, and only about a century where things have really started to change,” he says. This visualization is a time-series of the global distribution and variation of the concentration of mid-tropospheric carbon dioxide observed by the Atmospheric Infrared Sounder (AIRS) on the NASA Aqua spacecraft. For comparison, it is overlain by a graph of the seasonal variation and interannual increase of carbon dioxide observed at the Mauna Loa, Hawaii observatory. Please note, mid-tropospheric carbon dioxide shows a steady increase in atmospheric carbon dioxide concentrations over time. Credit: NASA Scientific Visualization Studio Fetzer is project scientist for the Atmospheric Infrared Sounder (AIRS) instrument on NASA’s Aqua satellite. Launched in 2002, AIRS is one of six instruments aboard Aqua. At the time of its launch, AIRS was the most advanced atmospheric sounding system ever deployed in space, and it continues to make major contributions to our understanding of climate. During its 17 years in orbit, AIRS data have also improved operational weather forecasts around the world, and the instrument measures atmospheric temperature, water vapor and a number of trace gases, including carbon dioxide, ammonia, methane and carbon monoxide. Fetzer highlighted a few of AIRS’ many scientific achievements. “We found that Earth’s climate system has responded to increasing carbon dioxide concentrations as climate models predicted,” he said. “Atmospheric water vapor is sensitive to the presence of carbon dioxide. The more carbon dioxide, the more the atmosphere warms due to the greenhouse effect. A warmer atmosphere holds more water vapor, which is itself a greenhouse gas. This is how water vapor triples the warming from increasing carbon dioxide and other greenhouse gases.” The streak of red, orange, and yellow across South America, Africa, and the Atlantic Ocean in this animation points to high levels of carbon monoxide, as measured by the Atmospheric Infrared Sounder (AIRS) instrument flying on NASA's Aqua satellite. The carbon monoxide primarily comes from fires burning in the Amazon basin, with some additional contribution from fires in southern Africa. Credit: NASA-JPL/Caltech/NASA Scientific Visualization Studio AIRS data have detected significant changes in the climate of the Arctic. “We see increases in Arctic water vapor levels,” he said. “The Arctic atmosphere is becoming more moist, adding to its warming, and the ocean is becoming more ice-free. These changes are happening more rapidly than scientists expected. I didn’t anticipate seeing them in a 17-year data record.” Fetzer said the AIRS team has also observed significant increases in the concentration of atmospheric ammonia in areas like northern India and eastern China due to agricultural activities. This has negatively impacted air quality in these regions. Fetzer added that while greenhouse gases are arguably the biggest driver of global climate change, other chemicals such as carbon monoxide and ammonia are also changing significantly, and AIRS is tracking those changes. This visualization shows 3D volumetric water vapor data from the Aqua/Atmospheric Infrared Sounder (AIRS) instrument. As the camera moves down and around the data set, the low data values fade out, revealing only the highest concentrations of water vapor data. The color and opacity at each 3D voxel are driven by the water vapor data. The data set was obtained by Aqua on January 1, 2003. Only data from sea level to about 10 km (about 6 miles) are shown. Credit: NASA/GSFC Scientific Visualization Studio While a replacement for AIRS was not specifically called out in the latest National Academy of Sciences’ Earth science decadal survey, which provides a roadmap for future Earth science satellite missions, Fetzer’s team is still planning for such a possibility. “Most NASA instruments are typically one-of-a-kind, and there aren’t usually plans for replacements,” he said. “In the years since AIRS was developed, atmospheric sounding techniques have changed significantly. But while the technologies may be different, the nature of the measurement remains the same.” In fact, says Fetzer, many of the instruments developed in recent years to measure the atmosphere derive heritage from AIRS. For example, techniques developed for use on AIRS have been applied to such missions as the Cross-track Infrared Sounder (CrIS) instrument on the NASA/NOAA Suomi National Polar-orbiting Partnership (NPP) satellite, NOAA’s Joint Polar Satellite System (JPSS)-1 satellite, and the Infrared Atmospheric Sounding Interferometer (IASI) instruments on the three polar-orbiting MetOp meteorological satellites developed by the European Space Agency and operated by the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT). “Even if an AIRS replacement is never built, AIRS has firmly cemented its place in atmospheric science history,” he said. For more on AIRS, visit https://airs.jpl.nasa.gov/. Part Four of this series: 'The Atmosphere: Fresh Insights on Air Quality, Ozone and Climate​'
  • Can Climate Affect Earthquakes, Or Are the Connections Shaky?
    The twin magnitude 6.4 and 7.1 earthquakes that struck the Ridgecrest area in California’s Mojave Desert northeast of Los Angeles on July 4 and 5, respectively, were felt by up to 30 million people in California, Nevada, Arizona and Baja California, resulting in loss of life, injuries, billions in damage and lots of frazzled nerves. While the remote location undoubtedly minimized impacts, the quakes did serve as a wake-up call for complacent Californians that they live in Earthquake Country and need to prepare for the inevitable “Big One” that scientists say is sure to come. They also got people talking about all aspects of earthquakes. There are lots of myths about earthquakes. A common one is that there’s such a thing as “earthquake weather” — certain types of weather conditions that typically precede earthquakes, such as hot and dry, or dry and cloudy. The myth stems from the Greek philosopher Aristotle, who proposed in the 4th century B.C. that earthquakes were caused by trapped winds escaping from subterranean caves. He believed the large amounts of air trapped underground would make weather on Earth’s surface before a quake hot and calm. With the advent of seismology — the study of earthquakes — we now know that most quakes are caused by tectonic processes — forces within the solid Earth that drive changes in the structure of Earth’s crust, primarily the rupture of underground rock masses along faults (linear zones of weakness). We also know that most earthquakes occur far beneath Earth’s surface, well beyond the influence of surface temperatures and conditions. Finally, we know the statistical distribution of earthquakes is approximately equal across all types of weather conditions. Myth busted. In fact, according to the U.S. Geological Survey, the only correlation that’s been noted between earthquakes and weather is that large changes in atmospheric pressure caused by major storms like hurricanes have been shown to occasionally trigger what are known as “slow earthquakes,” which release energy over comparatively long periods of time and don’t result in ground shaking like traditional earthquakes do. They note that while such large low-pressure changes could potentially be a contributor to triggering a damaging earthquake, “the numbers are small and are not statistically significant.” But what about climate? Are there any connections between climate phenomena and earthquakes? We asked geophysicist Paul Lundgren of NASA’s Jet Propulsion Laboratory in Pasadena, California, to do a scientific shakedown on the matter. Weighing the Seismic Consequences of Water In order to make any connection between climate and earthquakes, says Lundgren, you first have to determine what kinds of tectonic processes might be related to climate phenomena. Scientists know earthquakes can be triggered or inhibited by changes in the amount of stress on a fault. The largest climate variable that could change fault stress loads is surface water in the form of rain and snow. Lundgren says several studies have supported such correlations. But there’s a catch. “Typically, where we’ve seen these types of correlations is in microseismicity -- tiny earthquakes with magnitudes less than zero, far smaller than humans can feel,” he said. “Those occur quite frequently.” Lundgren cited work by his colleague Jean-Philippe Avouac at Caltech and others, who’ve found a correlation between the amount of microseismicity in the Himalaya and the annual monsoon season. During the summer months, large amounts of precipitation fall on the Indo-Gangetic Plain, which encompasses the northern regions of the Indian subcontinent. This increases stress loads on Earth’s crust there and decreases levels of microseismicity in the adjacent Himalaya. During the winter dry season, when there’s less water weight on Earth’s crust in the plain, Himalayan microseismicity peaks. Advancing monsoon clouds and showers in Aralvaimozhy, near Nagercoil, India. Precipitation during the annual monsoon season in the Indo-Gangetic Plain increases stress loads on Earth’s crust there and decreases the number of microearthquakes in the adjacent Himalaya. Conversely, during the dry season, the reduced water weight on Earth’s crust in the plain causes microseismicity in the Himalaya to peak. Credit: w:user:PlaneMad [CC BY-SA 3.0] Lundgren says it gets much more difficult, however, to make such inferences about larger earthquakes. “We’ve seen that relatively small stress changes due to climate-like forcings can effect microseismicity,” he said. “A lot of small fractures in Earth’s crust are unstable. We see also that tides can cause faint Earth tremors known as microseisms. But the real problem is taking our knowledge of microseismicity and scaling it up to apply it to a big quake, or a quake of any size that people could feel, really.” Climate-related stress changes might or might not promote an earthquake to occur, but we have no way of knowing by how much. “We don’t know when a fault may be at the critical point where a non-tectonic forcing related to a climate process could be the straw that breaks the camel’s back, resulting in a sizeable earthquake, and why then and not earlier?” he said. “We’re simply not in a position at this point to say that climate processes could trigger a large quake.” What About Droughts? We know seasonal effects can cause changes on faults, but what about less periodic climate phenomena, like a long-term drought? Might they cause changes too? As it turns out, changes in stress loads on Earth’s crust from periods of drought can, in fact, be significant. Research by JPL scientist Donald Argus and others in 2017 using data from a network of high-precision GPS stations in California, Oregon and Washington found that alternating periods of drought and heavy precipitation in the Sierra Nevada between 2011 and 2017 actually caused the mountain range to rise by nearly an inch and then fall by half that amount, as the mountain rocks lost water during the drought and then regained it. The study didn’t specifically look at potential impacts on faults, but such stress changes could potentially be felt on faults in or near the range. The Sierra Nevada range in California rose almost an inch between 2011 and 2015 during a period of drought due to loss of water from within fractured rocks. Such changes in stress loads on Earth’s crust could potentially be felt on faults in or near the range. Credit: trailkrum, CC-BY-2.0 Similarly, pumping of groundwater from underground aquifers by humans, which is exacerbated during times of drought, has also been shown to impact patterns of stress loads by “unweighting” Earth’s crust. Lundgren pointed to a 2014 study in the journal Nature by Amos et al. that looked at the effects of groundwater extraction in California’s Central Valley on seismicity on the adjacent San Andreas Fault. The researchers found that such extractions can promote lateral changes in stress to the two sides of the San Andreas, which move horizontally against each other along the boundary of two major tectonic plates. This could potentially cause them to unclamp and slip, resulting in an earthquake. Subsidence in California's San Joaquin Valley for the period May 3, 2014 to Jan. 22, 2015, as measured by Canada's Radarsat-2 satellite. A 2014 Nature study found groundwater pumping can promote lateral stress changes on the San Andreas Fault, potentially causing them to unclamp, resulting in an earthquake. Credit: Canadian Space Agency/NASA/JPL-Caltech “Such stresses are small, but if you have groundwater pumping over a long period of time, then they could become more significant,” he said. “Even though such changes might be small compared with stress changes caused by the normal buildup of stress on a fault from tectonic processes, it could potentially hasten the onset of the next big quake on the San Andreas. In addition, because the amount of slip on a fault increases with time between earthquakes, this could result in more frequent but smaller quakes.” However, says Lundgren, the Fort Tejon segment of the San Andreas Fault that is nearest to the Central Valley last ruptured in 1857, so given the erratic nature of earthquakes along the fault and the great variability in time between events, with our current level of knowledge, scientists are far from understanding when and where the next large earthquake will occur on it. Fire and Ice: Glaciers and Tectonic Processes Eruption at Iceland’s Holuhraun lava field, September 4, 2014. A 2017 study of Iceland volcanic activity 4,500 to 5,500 years ago found a link between deglaciation and increased volcanic activity. Credit: peterhartree [CC BY-SA 2.0] Another climate-related phenomenon that’s believed to have connections to tectonic processes is glaciation. The retreat of a glacier can reduce stress loads on Earth’s crust underneath, impacting the movement of subsurface magma. A recent study in the journal Geology on volcanic activity in Iceland between 4,500 and 5,500 years ago, when Earth was much cooler than today, found a link between deglaciation and increased volcanic activity. Conversely, when glacial cover increased, eruptions declined. The rapid movement of glaciers has also been shown to cause what are known as glacial earthquakes. Glacial earthquakes in Greenland peak in frequency in the summer months and have been steadily increasing over time, possibly in response to global warming. Human Uses of Water and Induced Seismicity In addition to climate-related impacts of water on seismicity, human management and applications of water can also affect earthquakes through a phenomenon known as induced seismicity. For example, water stored in large dams has been linked to earthquake activity in various locations around the world, though the impact is localized in nature. In 1975, approximately eight years after Northern California’s Lake Oroville, the state’s second-largest human-built reservoir, was created behind the Oroville Dam, a series of earthquakes occurred nearby, the largest registering magnitude 5.7. Shortly after the water in the reservoir was drawn down to its lowest level since it was originally filled in order to repair intakes to the dam’s power plant and then refilled, the earthquakes occurred. Lake Oroville in California was the site of a magnitude 5.7 earthquake in 1975 that was linked to changing stress loads on a local fault triggered by fluctuations in the reservoir’s water level. Credit: Quinn Comendant [CC BY-SA 2.0] Several studies investigating the quakes concluded that fluctuations in the reservoir level, and corresponding changes in the weight of the reservoir, changed the stress loads on a local fault, triggering the quakes. Monitoring of earthquake activity at the reservoir in the years following the quakes established a seasonal correlation between the reservoir’s level and seismicity. Seismicity decreases as the reservoir fills in winter and spring, and the largest earthquakes tend to occur as the reservoir level falls in the summer and fall. Induced seismicity can also occur when human water applications lubricate a fault. Studies by USGS and other institutions have linked sharp increases in earthquake activity in Oklahoma and other Midwest and Eastern U.S. states in recent years to increases in the practice of injecting wastewater into the ground during petroleum operations. Injection wells place fluids underground into porous geologic formations, where scientists believe they can sometimes enter buried faults that are ready to slip, changing the pore pressure on them and causing them to slip. House damage in central Oklahoma from the magnitude 5.6 earthquake on Nov. 6, 2011. Research conducted by USGS geophysicist Elizabeth Cochran and her university-based colleagues suggests that this earthquake was induced by injection into deep disposal wells in the Wilzetta North field. Credit: USGS/Brian Sherrod Getting the Big Picture of the Earth System’s Interconnectivity Lundgren says when he first started studying earthquakes, everything was focused on understanding them within the context of plate tectonics and processes happening within Earth’s crust. But that’s now changing. “In the past decade or so, with the widespread adoption of new technologies such as GPS that have greater spatial distribution and sensitivity, people have also begun looking at other second-order effects — other factors that might have an influence on earthquakes,” he said. “It’s very intriguing to be able to find potential links between earthquakes and climate, such as seasonal differences. The challenge, however, is squaring such connections with fundamental physics. “We’re not close to being able to predict when an earthquake may occur as a result of climate processes,” he concluded. “Even if we know that some outside climate process is potentially affecting a fault system, since we don’t know the fault’s potential state of readiness to break, we can’t yet make that extra inference to say, ah ha, I might get a quake a week or a month later.” What these studies do emphasize is the incredible complexity of our Earth system. Continued research will help us better unravel how its various components are interconnected, sometimes in surprising ways.
  • The Atmosphere: Fresh Insights on Air Quality, Ozone and Climate
    Part Four While satellite data have revolutionized how we view Earth and its atmosphere, people don’t need to travel to space to understand that our Blue Planet really isn’t that big and our atmosphere not very thick. In fact, says atmospheric scientist Bryan Duncan of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, all you have to do is, in the words of Oscar Hammerstein, climb every mountain. “From the perspective of air pollution and human health, there’s only a small amount of Earth’s atmosphere that we can actually breathe or live in,” Duncan said. “Take Mount Everest, for example. It’s only habitable for humans for the first few, lowest kilometers.” As project scientist for NASA’s Aura satellite, Duncan has seen how much humans are affecting Earth’s atmosphere and the quality of the air we breathe. Aura, launched in 2004 as a key component of NASA’s Earth Observing System, studies Earth’s ozone layer, air quality and climate. The mission has been instrumental in expanding our understanding of the composition, chemistry and dynamics of Earth’s atmosphere. NASA’s Aura satellite. Credit: NASA “Humans have been modifying our environment for thousands of years,” Duncan said. “Earth monitoring satellites have clearly shown that humans are changing our atmosphere, even over the 15 years Aura has been in orbit. We clearly see major changes in air pollution around the world. For example, we’ve observed that air pollution in the United States and Europe has been reduced, demonstrating the effectiveness of policy initiatives such as the Clean Air Act and other environmental regulations, but in other places, such as India, it’s getting worse. We’ve also seen improvements in regions like China.” (Trends for air pollutants around the world, many of which are based upon Aura data, may be seen at http://airquality.gsfc.nasa.gov.) Duncan says Aura has benefitted science and society in two primary ways. First, it has allowed us to better understand and observe the atmospheric chemistry and dynamics that determine Earth’s protective ozone layer. Aura data have allowed us to not only monitor ozone, but also to observe the chemicals involved in ozone’s formation and destruction. This information is helping scientists understand why the ozone layer is varying over time, including how human-produced ozone-destroying chemicals thinned the ozone layer and caused the “ozone hole” over Antarctica. Aura’s Ozone Monitoring Instrument (OMI) continues to observe stratospheric ozone, a record begun in 1970 with Nimbus-4/Backscatter Ultraviolet (BUV). Credit: NASA Second, it has provided some of the first long-term observations of air pollutants around the world. These include chemicals such as sulfur dioxide, formaldehyde and nitrogen dioxide, which is primarily produced by burning fossil fuels in vehicles and power plants and contributes to surface-level ozone. “Aura has really given us a window into some of the most important pollutants and how they’re changing over time,” he said. Satellite data show that Los Angeles has seen a 40 percent decrease in nitrogen dioxide between the 2005-2007 and the 2009-2011 periods. Cities in the U.S. West tend to be more geographically isolated than those in the U.S. East, which means that air pollution in one city is usually not a problem for cities downwind. However, western topography comes with its own issues. Bound by mountains, the Los Angeles basin forms a trap for pollution. Even so, factors including technology improvements have led to cleaner air. Credit: NASA/GSFC Scientific Visualization Studio/T. Schindler Aura launched with four instruments, two of which are still in operation: the Ozone Monitoring Instrument (OMI), the first satellite instrument to give us a long-term record of air pollution at high spatial resolution; and the Microwave Limb Sounder (discussed in Part Three of this series), which measures naturally occurring microwaves at the edge of the atmosphere to track stratospheric atmospheric gases, temperature, pressure and cloud ice. Aura’s other two instruments were the Tropospheric Emission Spectrometer (discussed in Part One of this series) and the High-Resolution Dynamics Limb Sounder. The Aura spacecraft is healthy and is expected to continue operating until it runs out of fuel in 2025. In addition to Aura, the other two flagship missions in NASA’s Earth Observing System — Terra and Aqua — have also made major contributions to understanding Earth’s atmosphere. “While Terra and Aqua were designed to monitor Earth’s land surface and hydrosphere (all water on, under and above Earth’s surface), respectively, they’ve also contributed to atmospheric science with instruments like the Atmospheric Infrared Sounder (AIRS) on Aqua, the Multi-angle Imaging SpectroRadiometer (MISR) on Terra, and the Moderate Resolution Imaging Spectroradiometers (MODIS) on Aqua and Terra, which monitor particulate matter (the solid and liquid particles suspended in the air) around the world,” Duncan said. Global satellite-derived map of PM2.5 averaged over 2001-2006. Credit: Dalhousie University, Aaron van Donkelaar “Our job as scientists is to make these satellite data sets available, help interpret them, and ensure they’re clear enough so that they can be used to create effective and efficient policy,” he concluded. “That way, they can be used to create positive change in society.” For more on Aura, visit https://aura.gsfc.nasa.gov/. Part Three of this series: 'The Atmosphere: Tracking the Ongoing Recovery of Earth's Ozone Hole' Next up: 'The Atmosphere: Keeping a Weather Eye on Earth’s Climate Instabilities'
  • Two Decades of Rain, Snowfall from NASA's Precipitation Missions
    NASA’s Precipitation Measurement Missions (PMM) have collected rain and snowfall from space for nearly 20 years, and for the first time in 2019, scientists can access PMM’s entire record as one data set. By being able to compare and contrast past and present data, researchers can make climate and weather models more accurate, better understand normal and extreme rain and snowfall around the world, and strengthen applications for current and future disasters, disease, resource management, energy production and food security. Credit: NASA's Goddard Space Flight Center/Ryan Fitzgibbons PMM includes two missions – the Tropical Rainfall Measuring Mission (TRMM), which orbited Earth from 1997 to 2015, and its successor, the joint NASA-JAXA Global Precipitation Measurement mission (GPM), which has been collecting data since 2014. This year, however, the GPM project upgraded its data algorithms to calibrate and incorporate TRMM data into its release, giving researchers, modelers and meteorologists access to the entire 19-year record. By being able to compare and contrast past and present data, researchers are better informed to make climate and weather models more accurate, better understand normal and extreme rain and snowfall around the world, and strengthen applications for current and future disasters, disease, resource management, energy production and food security. Watching Precipitation to Improve the World GPM provides a four-dimensional view of rain, snow, sleet and storms from space: It not only records the size of droplets or pellets, but how heavy the precipitation is and how it changes over time. This perspective is used not only for global science, like studying Earth’s water and energy cycles and spotting extreme weather around the world, but it is also useful for studying single events, like hurricanes or droughts. GPM’s signature algorithm is the Integrated Multi-satellitE Retrievals for GPM, or IMERG. IMERG calibrates and combines data from its main satellite, the GPM Core Observatory, and the GPM Constellation, a group of international satellites that contribute data to GPM while also performing their own missions. While the full IMERG product takes time to process and prepare, it also generates a near-real-time summary of global precipitation every half-hour, which is useful for time-sensitive applications like weather forecasting and disaster recovery. Researchers, emergency responders, health professionals and resource managers use IMERG data to see how precipitation shaped events in the past, to help them prepare for similar events in the future. By creating a reliable, multiple-decade baseline of rain and snow, IMERG shows how precipitation may deviate from normal, informing models that predict crop yields, disease outbreaks and landslides. IMERG data also support applications like water resource management, said Andrea Portier, GPM’s applications coordinator. For example, in the Navajo nation, located in the southwestern United States, precipitation data are critical for water resource managers supervising scarce water for farming, drinking and caring for animals. GPM rainfall measurements and maps help them know what areas are at risk of drought. Eyeing the Past to Predict the Future Studying IMERG data from a longer perspective gives scientists a different view: What regions received the most or least rainfall, where did the biggest storms strike, how does precipitation change across the seasons? “For the last five years, with GPM, we’ve had a multi-satellite precision data set that covers practically the whole world,” said George Huffman, IMERG’s lead scientist and GPM’s deputy project scientist. “But five years is a short time. We needed to have something longer … extending the multi-satellite record over the entire two missions gives us a chance to get long-term statistics and analyze past conditions.” One important application for past precipitation data is in weather and climate modeling, the foundation for studying short-term weather and long-term climate regionally and globally. Scientists use sophisticated computer programs to analyze large quantities of observed data on air temperature, atmospheric pressure, wind, precipitation, soil moisture and many other variables. These computer programs then generate forecasts for short-term weather or long-term climate. “We need the past to model the future. The past gives us the baseline we need to understand future events,” said Dalia Kirschbaum, GPM’s deputy project scientist for applications. “For example, in the case of extreme weather, like hurricanes, we can better understand what ‘extreme’ means if we have a baseline for comparison. This update is a milestone by supporting more accurate precipitation estimates that can be used as ‘ground truth’ in working toward more accurate future predictions.” Another set of processes the team hopes to understand more completely are changes in precipitation from day to night and across seasons. “One of the important things we’re looking for is understanding how the Earth system works,” Huffman said. “GPM gives us information about what the environment is doing and enables us to look at how rainfall may interact with other Earth system variables, such as soil moisture, air quality and vegetation.” On the Navajo nation, located in the southwestern United States, precipitation data are critical for water resource managers supervising scarce water for farming, drinking and caring for animals. GPM rainfall measurements and maps help them know what areas are at risk of drought and in need of additional care. Credit: NASA / Amber McCullum By looking back to see where rain and snow fell in the past 19 years, scientists can help people around the world prepare for the future, from localized short-term drizzles to large-scale, decadal patterns. Data from both GPM and TRMM are free and available to the public. The PMM website lists the access points for various datasets and provides tutorials and webinars on how to download and use them. The tutorials range from basic data access and use to specific applications, such as flood management, agriculture, and disease monitoring and response. IMERG will continue providing data for the life of the GPM mission, expected to last to the mid-2030s or beyond. For more information about PMM or to get started using GPM and TRMM data, visit https://pmm.nasa.gov/.
  • NASA's Role in Studying Earth's Atmosphere
    Studying Earth’s atmospheric composition is a key focus area for NASA’s Science Mission Directorate and Earth Science Division. NASA’s Atmospheric Composition focus area conducts research on Earth’s atmosphere, including its chemical and physical properties, Earth’s energy budget and air quality. The focus area studies the variations in and processes that affect aerosols, clouds and trace gases like ozone, which influence climate, weather and air quality. The Atmospheric Composition focus area provides observations and modeling tools to assess the effects of climate change on ozone recovery and future atmospheric composition; improve climate forecasts based on fluctuations in global environmental change; and model past, present and future air quality, both regionally and globally. This research, combined with observations, data assimilation and modeling, improves society’s ability to predict how future changes in atmospheric composition will affect climate, weather and air quality. NASA researchers are interested in the following overarching research questions: How is atmospheric composition changing? What trends in atmospheric composition and solar radiation influence global climate? How does atmospheric composition respond to and affect global environmental change? What are the effects of global atmospheric composition and climate change on regional air quality? How will future changes in atmospheric composition affect ozone, climate and global air quality? The agency’s four major atmospheric composition research programs include: The Upper Atmosphere Research Program (UARP), which studies the processes and reactions that control the amount of ozone in the upper troposphere and stratosphere. The Tropospheric Composition Program (TCP), which studies global tropospheric ozone and aerosols, including their chemical precursors and the reactions involved in their formation and transformation into other chemical compounds. These measurements are fundamental to better understanding air quality and climate. The Radiation Sciences Program (RSP), which conducts research to better understand and predict how aerosols, clouds and gases scatter and absorb both solar and terrestrially emitted radiation in Earth’s atmosphere, especially as it relates to climate variability and change. The Atmospheric Composition Modeling and Analysis Program (ACMAP), which uses models to help integrate observations from multiple satellite, airborne- and ground-based instruments in four main areas: air quality and oxidation efficiency in the troposphere, how pollution-sourced aerosols affect cloud properties, stratospheric chemistry and ozone depletion and interactions between atmospheric chemistry and climate. These programs are supported by NASA’s broad fleet of Earth observing satellites, together with numerous ground- and aircraft-based suborbital investigations. A number of additional satellite and aircraft missions are currently in development or under study. Table listing the missions, campaigns, and instruments relevant to NASA’s Atmospheric Composition focus area in all phases of operation. Credit: NASA For more on how NASA studies Earth’s atmosphere, visit: https://science.nasa.gov/earth-science/programs/research-analysis/atmospheric-composition — Alan Buis/NASA's Global Climate Change website ‹ Back to main article: 'The Atmosphere: Tracking the Ongoing Recovery of Earth's Ozone Hole'
  • The Atmosphere: Tracking the Ongoing Recovery of Earth's Ozone Hole
    Part Three As discussed earlier in this feature series (see Parts One and Two), Earth’s atmosphere is largely able to cleanse itself of pollutants, but there are a few things that humans have produced that are much more long-lived when emitted into the atmosphere, degrading its quality and creating harmful environmental effects. One such family of chemical compounds is chlorofluorocarbons (CFCs), whose contribution to depleting ozone in Earth’s upper atmosphere has led to large springtime decreases in ozone around Earth’s polar regions, especially over Antarctica, a phenomenon known as the ozone hole that was first reported in 1985. But, as NASA atmospheric scientist Nathaniel Livesey explains, today, thanks to the phase-out of CFCs, Earth’s ozone hole is in recovery. He says the turnaround provides a great example of what humans can do when they work together to solve a global atmospheric problem. “Humans produced a lot of CFCs from the 1950s through the early 1990s that were useful for a variety of purposes and widely adopted around the world,” said Livesey, principal investigator for the Microwave Limb Sounder (MLS) instrument on NASA’s Aura satellite at NASA’s Jet Propulsion Laboratory in Pasadena, California. The CFCs were added to the atmosphere at the parts per billion level. “But CFCs were also very effective at depleting stratospheric ozone, which protects us from harmful solar ultraviolet radiation, and their use created a hole in Earth’s stratospheric ozone layer. Luckily, we were able to identify the problem in time and come to a worldwide agreement, the Montreal Protocol, which phased out their use.” Long-term changes in Arctic total ozone are evident in this series of total ozone maps derived from satellite observations. Each map is an average during March, the month when some ozone depletion is usually observed in the Arctic. In the 1970s, the Arctic region had normal ozone values in March, with values of 450 DU and above (red colors). Ozone depletion on the scale of the Antarctic ozone hole does not occur in the Arctic. Instead, late winter/early spring ozone depletion has eroded the normal high values of total ozone. On the maps from the late 2000s and early 2010s, the extent of values of 450 DU and above is greatly reduced in comparison with the 1970s maps. The large regions of low total ozone in 1997 and 2011 (blue colors) are unusual in the Arctic record, but not unexpected. The meteorological conditions led to below-average stratospheric temperatures and a strong polar vortex in these winters, conditions favorable to strong ozone depletion. Credit: NOAA Under the Montreal Protocol, which was finalized in 1987, and its 2016 amendment, a multi-phased plan was implemented involving the use of hydrochlorofluorocarbons (HCFCs), which aren’t as damaging to the environment as CFCs and could be used in the same equipment, since their chemical structure is very similar to CFCs. But HCFCs also contribute to ozone layer destruction, albeit at a smaller rate than CFCs did, as well as to global warming, so their use is also being gradually phased out over the next decade. While the Montreal Protocol is a great success story, Livesey cautions that tackling Earth’s carbon dioxide and methane emission problems will be more difficult to address. “People everywhere used CFCs but, in actuality, there were only about four companies in the world that actually produced them,” he said. “With carbon dioxide, the problem is much more complex. All of us produce carbon dioxide. And there are way more coal-burning power plants than there ever were CFC plants. Methane emissions resulting from human activities are also a major contributor. So it’s very hard to point to one thing to fix the problem like we could with CFCs.” Livesey says Earth’s recent temperature increases simply cannot be explained without accounting for human emissions of carbon dioxide, which builds up over time and has a long life once emitted into the atmosphere. To those who claim that carbon dioxide, methane and other greenhouse gases don’t have a significant impact on global warming, he offers a simple scientific experiment. Left: Ozone in Earth's stratosphere at an altitude of approximately 12 miles (20 kilometers) in mid-March 2011, near the peak of the 2011 Arctic ozone loss. Red colors represent high levels of ozone, while purple and grey colors (over the north polar region) represent very small ozone amounts. Right: chlorine monoxide — the primary agent of chemical ozone destruction in the cold polar lower stratosphere — for the same day and altitude. Light blue and green colors represent small amounts of chlorine monoxide, while dark blue and black colors represent very large chlorine monoxide amounts. The white line marks the area within which the chemical ozone destruction took place. Credit: NASA-JPL/Caltech “Take a gallon of water and put a drop of food coloring in it. You’re going to immediately notice a change,” he said. “The same is true for adding trace greenhouse gases to the atmosphere. It doesn’t take very much of an increase before their presence literally changes the color of the atmosphere as observed by infrared satellite instruments.” Livesey says the MLS instrument has contributed to our understanding of atmospheric ozone. For example, it’s been instrumental in verifying the recovery of the ozone layer. MLS has also contributed to studies of how much stratospheric ozone descends into the lower atmosphere, contributing to surface pollution. Surface-level ozone pollution has a detrimental impact on plant growth, resulting in billions of dollars in estimated crop losses. “NASA is mandated to study the upper atmosphere, and the word ozone appears in that mandate,” Livesay says. “It’s also in the U.S. Clean Air Act. NASA has spearheaded numerous ozone research campaigns and has contributed to many of the big-name atmospheric ozone models. We’ve done a lot of work on satellite measurements of air quality. And the A Train constellation of atmospheric research satellites, of which Aura/MLS is one component, has been a huge benefit to the atmospheric science community.” (Learn more about NASA's role in studying Earth's atmosphere.) The A Train satellite constellation. Credit: NASA In addition to ozone, MLS tracks water vapor, numerous trace gasses and mid-atmospheric temperatures. MLS observes the details of ozone chemistry by measuring many radicals, reservoirs, and source gases in chemical cycles that destroy ozone. Credit: NASA/GSFC Scientific Visualization Studio Regarding water vapor, Livesey says scientists still don’t fully understand the processes that control humidity in the stratosphere. For example, in 2000, measurements showed the amount of stratospheric water vapor decreased by about 10 percent, which slowed the rate of global surface temperature increases by about 25 percent. But scientists are still not completely sure why it decreased. “Since stratospheric water vapor is a greenhouse gas, we want to be able to predict its future evolution well,” he said. “We don’t yet fully understand the interplay of the various processes involved and how they will evolve in a warming climate. MLS data are contributing to atmospheric models that are assisting in this area of research.” One of the biggest surprises from MLS data has been its observations of a phenomenon that allows pollution from strong forest fires to penetrate into the stratosphere. Fires are a significant contributor to stratospheric aerosols and thus have the potential to affect surface warming. “MLS has allowed us to track this pollution around the globe. We wouldn’t have guessed before that a single forest fire could do that,” Livesey said.” A trio of NASA satellites observe in synchrony the vertical structures of thunderstorms (lower track) and their influences on ice clouds (color shades), water vapor (contours) and pollutants just above Earth's lower atmosphere (higher track). Credit: Rong Fu, Cinda Gillilan, Jonathan H. Jiang and Brian Knosp As the MLS data record approaches 15 years, Livesey says he’s hopeful MLS will continue to provide important science for several more years. The instrument continues to work well and the biggest limitation on its life is the amount of fuel on the Aura spacecraft, which should run out in about 2025, although the team is considering adopting a less fuel-intensive orbit maintenance strategy that could add several more years of operations. “The longer our data record goes, the more valuable it becomes,” he said. For more on MLS, visit https://mls.jpl.nasa.gov/index-eos-mls.php. Part Two of this series: 'The Atmosphere: Getting a Handle on Carbon Dioxide' Next up: 'The Atmosphere: Fresh Insights on Air Quality, Ozone and Climate'
  • The Atmosphere: Getting a Handle on Carbon Dioxide
    Part Two Earth’s atmosphere is resilient to many of the changes humans have imposed on it. But, says atmospheric scientist David Crisp of NASA’s Jet Propulsion Laboratory in Pasadena, California, that doesn’t necessarily mean that our society is. “The resilience of Earth’s atmosphere has been proven throughout our planet’s climate history,” said Crisp, science team lead for NASA’s Orbiting Carbon Observatory-2 (OCO-2) satellite and its successor instrument, OCO-3, which launched to the International Space Station on May 4. “Humans have increased the abundance of carbon dioxide by 45 percent since the beginning of the Industrial Age. That’s making big changes in our environment, but at the same time, it’s not going to lead to a runaway greenhouse effect or something like that. So, our atmosphere will survive, but, as suggested by UCLA professor and Pulitzer-Prize-winning author Jared Diamond, even the most advanced societies can be more fragile than the atmosphere is.” NASA’s OCO-3 instrument sits on the large vibration table (known as the "shaker") in the Environmental Test Lab at NASA’s Jet Propulsion Laboratory. Thermal blankets were later added to the instrument at NASA’s Kennedy Space Center, where a Space-X Dragon capsule carrying OCO-3 launched on a Falcon 9 rocket to the space station on May 4, 2019. Credit: NASA/JPL-Caltech Changes to our atmosphere associated with reactive gases (gases that undergo chemical reactions) like ozone and ozone-forming chemicals like nitrous oxides, are relatively short-lived. Carbon dioxide is a different animal, however. Once it’s added to the atmosphere, it hangs around, for a long time: between 300 to 1,000 years. Thus, as humans change the atmosphere by emitting carbon dioxide, those changes will endure on the timescale of many human lives. Earth’s atmosphere is associated with many types of cycles, such as the carbon cycle and the water cycle. Crisp says that while our atmosphere is very stable, those cycles aren’t. “Humanity’s ability to thrive depends on these other planetary cycles and processes working the way they now do,” he said. “Thanks to detailed observations of our planet from space, we’ve seen some changes over the last 30 years that are quite alarming: changes in precipitation patterns, in where and how plants grow, in sea and land ice, in entire ecosystems like tropical rain forests. These changes should attract our attention. “One could say that because the atmosphere is so thin, the activity of 7.7 billion humans can actually make significant changes to the entire system,” he added. “The composition of Earth’s atmosphere has most certainly been altered. Half of the increase in atmospheric carbon dioxide concentrations in the last 300 years has occurred since 1980, and one quarter of it since 2000. Methane concentrations have increased 2.5 times since the start of the Industrial Age, with almost all of that occurring since 1980. So changes are coming faster, and they’re becoming more significant.” The concentration of carbon dioxide in Earth’s atmosphere is currently at nearly 412 parts per million (ppm) and rising. This represents a 48 percent increase since the beginning of the Industrial Age, when the concentration was near 280 ppm, and an 11 percent increase since 2000, when it was near 370 ppm. Crisp points out that scientists know the increases in carbon dioxide are caused primarily by human activities because carbon produced by burning fossil fuels has a different ratio of heavy-to-light carbon atoms, so it leaves a distinct “fingerprint” that instruments can measure. A relative decline in the amount of heavy carbon-13 isotopes in the atmosphere points to fossil fuel sources. Burning fossil fuels also depletes oxygen and lowers the ratio of oxygen to nitrogen in the atmosphere. A chart showing the steadily increasing concentrations of carbon dioxide in the atmosphere (in parts per million) observed at NOAA's Mauna Loa Observatory in Hawaii over the course of 60 years. Measurements of the greenhouse gas began in 1959. Credit: NOAA OCO-2, launched in July 2014, gathers global measurements of atmospheric carbon dioxide with the resolution, precision and coverage needed to understand how this important greenhouse gas — the principal human-produced driver of climate change — moves through the Earth system at regional scales, and how it changes over time. From its vantage point in space, OCO-2 makes roughly 100,000 measurements of atmospheric carbon dioxide every day. Artist’s rendering of NASA’s Orbiting Carbon Observatory (OCO)-2 in orbit above the U.S. upper Great Plains. Credit: NASA-JPL/Caltech Crisp says OCO-2 has already provided new insights into the processes emitting carbon dioxide to the atmosphere and those that are absorbing it. Map of the most persistent carbon dioxide “anomalies” seen by OCO-2 (i.e. where the carbon dioxide is always systematically higher or lower than in the surrounding areas). Positive anomalies are most likely sources of carbon dioxide, while negative anomalies are most likely to be sinks, or reservoirs, of carbon dioxide. Credit: NASA/JPL-Caltech “For as long as we can remember, we’ve talked about Earth’s tropical rainforests as the ‘lungs’ of our planet,” he said. “Most scientists considered them to be the principal absorber and storage place of carbon dioxide in the Earth system, with Earth’s northern boreal forests playing a secondary role. But that’s not what’s being borne out by our data. We’re seeing that Earth’s tropical regions are a net source of carbon dioxide to the atmosphere, at least since 2009. This changes our understanding of things.” Measurements of atmospheric carbon dioxide in the tropics are consistently higher than anything around them, and scientists don’t know why, Crisp said. OCO-2 and the Japan Aerospace Exploration Agency’s Greenhouse gases Observing SATellite (GOSAT) are tracking plant growth in the tropics by observing solar-induced fluorescence (SIF) from chlorophyll in plants. SIF is an indicator of the rate at which plants convert light from the Sun and carbon dioxide from the atmosphere into chemical energy. “We’re finding that plant respiration is outstripping their ability to absorb carbon dioxide,” he said. “This is happening throughout the tropics, and almost all of the time. When we first launched OCO-2, our first two years of on-orbit operations occurred during a strong El Niño event, which had a strong impact on global carbon dioxide emissions. Now we have more than five years of data, and we see that the tropics are always a source (of carbon dioxide), in every season. In fact, the only time we see significant absorption of carbon dioxide in the tropics is in Africa during June, July and August. So that’s half the story. The last El Niño in 2015-16 impacted the amount of carbon dioxide that Earth's tropical regions released into the atmosphere, , leading to Earth's recent record spike in atmospheric carbon dioxide. The effects of the El Nino were different in each region. Credit: NASA-JPL/Caltech “The other half is also quite interesting,” he added. “We’re seeing northern mid- and high-latitude rainforests becoming better and better absorbers for carbon dioxide over time. One possible explanation for this is that the growing season is getting longer. Things that didn’t used to grow well at high latitudes are growing better and things that were growing well there before are growing longer. We’re seeing that in our data set. We see that South America’s high southern latitudes — the so-called cone of South America — are also strong absorbers for carbon. We don’t know if it was always this way and our previous understandings were incomplete or wrong, or if climate change has increased the intensity of the growing season. So we’ve established a new baseline, and it appears to be somewhat of a paradigm shift. Our space-based measurements are beginning to change our understanding of how the carbon cycle works and are providing new tools to allow us to monitor changes in the future in response to climate change.” Crisp says OCO-2, OCO-3 and other new satellites are giving us new tools to understand how, where and how much carbon dioxide human activities are emitting into the atmosphere and how those emissions are interacting with Earth’s natural cycles. “We’re getting a sharper picture of those processes,” he said. Impacts from agricultural activities also seem to be changing, he says. During summer in the U.S. upper Midwest, scientists are seeing an intense absorption of carbon dioxide associated with agricultural activities. The same thing is being observed in Eastern and Southern Asia. The strong absorption of carbon dioxide across China is erasing all but a thin strip of fossil fuel emissions along the coast, with Central China now functioning as a net absorber of carbon dioxide during the growing season. Thanks to the development of big, sophisticated computer models combined with wind and other measurements, we’re able to quantify these changes for the first time. In response to the rapid changes observed in carbon dioxide concentrations and their potential impact on our climate, 33 of the world’s space agencies, including participants from the United States, Europe, Japan and China, are now working together to develop a global greenhouse gas monitoring system that could be implemented as soon as the late 2020s, Crisp added. The system would include a series of spacecraft making coordinated measurements to monitor these changes. Key components of the system would include the OCO-2 and OCO-3 missions, Japan’s GOSAT and GOSAT-2, and Europe’s Copernicus missions. The system would be complemented by ground-based and aerial research. Crisp said he and his fellow team members are eagerly poring over the first science data from OCO-3. The new instrument, installed on the exterior of the space station, will extend and enhance the OCO-2 data set by collecting the first dawn-to-dusk observations of variations in carbon dioxide from space over tropical and mid-latitude regions, giving scientists a better view of emission and absorption processes. This is made possible by the space station’s unique orbit, which carries OCO-3 over locations on the ground at slightly different times each orbit. NASA’s OCO-3 mission launched to the International Space Station on May 4, 2019. This follow-on to OCO-2 brings new techniques and new technologies to carbon dioxide observations of Earth from space. Credit: NASA-JPL/Caltech The Copernicus CO2 Mission, scheduled for launch around 2025, will be the first operational carbon dioxide monitoring satellite constellation. Crisp, who’s a member of its Mission Advisory Group, said the constellation will include multiple satellites with wide viewing swaths that will be able to map Earth’s entire surface at weekly intervals. While its basic measurement technique evolved from the GOSAT and OCO-2 missions, there’s a key difference: the earlier satellites are sampling systems focused on improving understanding of Earth’s natural carbon cycle, while Copernicus will be an imaging system focused on monitoring human-produced emissions. In fact, it will have the ability to estimate the emissions of every large power plant in every city around the world. Crisp says as time goes on the objective is to build an operational system that will monitor all aspects of Earth’s environment. Pioneering satellites like OCO-2, OCO-3, GOSAT and GOSAT-2 are adding greenhouse gas measurements to the data on temperature, water vapor, cloud cover, air quality and other atmospheric properties that have been collected for decades. “We know our atmosphere is changing and that these changes may affect our civilization,” he said. “We now have the tools to monitor our atmosphere very carefully so that we can give policymakers the best information available. If you’ve invested in a carbon reduction strategy, such as converting from coal to natural gas or transitioning from fossil fuels to renewables, wouldn’t you like to know that it worked? You can only manage what you can measure.” For more on OCO-2, visit https://ocov2.jpl.nasa.gov/. For more on OCO-3, visit https://ocov3.jpl.nasa.gov/. Part One of this series: 'The Atmosphere: Earth's Security Blanket' Next up: 'The Atmosphere: Tracking the Ongoing Recovery of Earth’s Ozone Hole​'
  • Successful Ocean-Monitoring Satellite Mission Ends
    if (typeof captions == 'undefined'){ var captions = []; } captions.push("The Jason-2/OSTM satellite provided insights into ocean currents and sea level rise with tangible benefits to marine forecasting, meteorology and understanding of climate change. These observations are being continued by its successor, Jason-3. Credit: NASA/JPL-Caltech › Larger view") captions.push("Jason-2/OSTM contributed to a long-term record of global sea levels. This image shows areas in the Pacific Ocean where sea levels were lower (blues) or higher (reds) than normal during the first week of January 2018. Credit: NASA/JPL-Caltech › Larger view") captions.push("Global sea level has shown a steady rise since the early 1990s to present as measured by Jason-2/OSTM and its predecessors and successor from the early 1990s to present day. Credit: NASA/JPL-Caltech › Larger view") $(document).ready(function(){ var type = "news"; var slider = new MasterSlider(); // adds Arrows navigation control to the slider. slider.control('bullets', {autohide: false}); slider.control('arrows'); homepage_slider_options = { width: $(window).width(), // slider standard width height: 400, // slider standard height layout: "autofill", space:5, fullwidth: true, autoHeight: false, //will expand to height of image autoplay: false, speed: 20, loop: true, instantStartLayers: true //disable to allow for layer transitions }; slider.setup('masterslider_3656' , homepage_slider_options); if (type == "news"){ slider.api.addEventListener(MSSliderEvent.CHANGE_START , function(){ $('.slider_caption').html(captions[slider.api.index()]); }); } }); The Jason-2/Ocean Surface Topography Mission (OSTM), the third in a U.S.-European series of satellite missions designed to measure sea surface height, successfully ended its science mission on Oct. 1. NASA and its mission partners made the decision to end the mission after detecting deterioration in the spacecraft's power system. Jason-2/OSTM, a joint NASA mission with the French space agency Centre National d'Etudes Spatiales (CNES), the National Oceanic and Atmospheric Administration (NOAA), and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), launched in June 2008. The mission extended the long-term record of sea surface height measurements started by the NASA-CNES TOPEX/Poseidon and Jason-1 missions. Jason-2/OSTM's 11-year lifetime well exceeded its three-year design life. These measurements are being continued by its successor, Jason-3, launched in 2016. "Today we celebrate the end of this resoundingly successful international mission," said Thomas Zurbuchen, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. "Jason-2/OSTM has provided unique insight into ocean currents and sea level rise with tangible benefits to marine forecasting, meteorology and our understanding of climate change." Since its launch, Jason-2/OSTM charted nearly 2 inches (5 centimeters) of global sea level rise, a critical measure of climate change. The mission has also resulted in the distribution of over a million data products and the publication of more than 2,100 science papers. "Jason-2/OSTM was a high point of operational satellite oceanography as the first Jason mission to formally include EUMETSAT and NOAA as partners," said Steve Volz, assistant administrator of NOAA's Satellite and Information Service. "During its 11-year run, Jason-2/OSTM helped improve NOAA's hurricane intensity forecasts and provided important observations of marine winds and waves and in doing so has anchored these essential ocean altimetry observations in NOAA's operational observing system requirements." With the recent degradation of the spacecraft's power system, mission partners decided to end the mission to decrease risks to other satellites and future altimetry missions, and to comply with French space law. Final decommissioning operations for Jason-2/OSTM are scheduled to be completed by CNES on Oct. 10. "With the involvement of EUMETSAT and NOAA, Jason-2 brought high precision monitoring of ocean surface topography and mean sea level to operational status," said Alain Ratier, EUMETSAT's director general. "Its 11-year lifetime in orbit was rewarding for the four program partners and the ocean and climate user community." Jason-2/OSTM's mission might have ended earlier if not for the ingenuity of its mission teams. In July 2017, the degradation of critical onboard components and control systems required that Jason-2/OSTM move from its original science orbit, deplete excess propellant reserves, and be maneuvered into a slightly lower orbit, away from functioning satellites. In close collaboration with the Ocean Surface Topography Science Team, mission partners identified an orbit that would allow for the continuation of the Jason-2/OSTM measurements while still being compatible with orbital-debris mitigation constraints and of scientific benefit. This new orbit resulted in less frequent observations of the same location on Earth, but overall resolution of the data improved because the ground tracks of the observations were closer together. This improved resolution is extremely useful for marine gravity studies and the mapping of seafloor topography. It also allowed for valuable operational oceanographic and science observations. "Not only did Jason-2 extend the precise climate record established by TOPEX/Poseidon and continued by Jason-1, it also made invaluable observations for small- to medium-scale ocean studies in its second, interleaved orbit," said CNES President Jean-Yves Le Gall. "Even when moved to the 'graveyard' orbit, Jason-2 continued to make unprecedented new observations of the Earth's gravity field, with precise measurements right until the end." The technological advancements proven on Jason-1, Jason-2/OSTM and Jason-3 will be put to use well into future decades. Following Jason-3 will be two future Sentinel-6/Jason-CS satellites, planned for launch in 2020 and 2025. For more information about NASA's Earth science activities, visit: https://www.nasa.gov/earth News Media Contacts Steve Cole NASA Headquarters, Washington 202-358-0918 stephen.e.cole@nasa.gov Esprit Smith Jet Propulsion Laboratory, Pasadena, Calif. 818-354-4269 esprit.smith@jpl.nasa.gov Pascale Bresson CNES, Paris, France 33-01-44-76-75-39 pascale.bresson@cnes.fr Raphaël Sart CNES, Paris, France 33-01-44-76-74-51 raphael.sart@cnes.fr John Leslie NOAA National Environmental Satellite and Information Service, Silver Spring, Md. 301-713-0214 john.leslie@noaa.gov Neil Fletcher EUMETSAT, Darmstadt, Germany 49-6151-807-8390 neil.fletcher@eumetsat.int
  • Earth's Atmosphere: A Multi-layered Cake
    Earth’s atmosphere has five major and several secondary layers. From lowest to highest, the major layers are the troposphere, stratosphere, mesosphere, thermosphere and exosphere. Troposphere. Earth’s troposphere extends from Earth’s surface to, on average, about 12 kilometers (7.5 miles) in height, with its height lower at Earth’s poles and higher at the equator. Yet this very shallow layer is tasked with holding all the air plants need for photosynthesis and animals need to breathe, and also contains about 99 percent of all water vapor and aerosols (minute solid or liquid particles suspended in the atmosphere). In the troposphere, temperatures typically go down the higher you go, since most of the heat found in the troposphere is generated by the transfer of energy from Earth’s surface. The troposphere is the densest atmospheric layer, compressed by the weight of the rest of the atmosphere above it. Most of Earth’s weather happens here, and almost all clouds that are generated by weather are found here, with the exception of cumulonimbus thunder clouds, whose tops can rise into the lowest parts of the neighboring stratosphere. Most aviation takes place here, including in the transition region between the troposphere and the stratosphere. Stratosphere. Located between approximately 12 and 50 kilometers (7.5 and 31 miles) above Earth’s surface, the stratosphere is perhaps best known as home to Earth’s ozone layer, which protects us from the Sun’s harmful ultraviolet radiation. Because of that UV radiation, the higher up you go into the stratosphere, the warmer temperatures become. The stratosphere is nearly cloud- and weather-free, but polar stratospheric clouds are sometimes present in its lowest, coldest altitudes. It’s also the highest part of the atmosphere that jet planes can reach. Mesosphere. Located between about 50 and 80 kilometers (31 and 50 miles) above Earth’s surface, the mesosphere gets progressively colder with altitude. In fact, the top of this layer is the coldest place found within the Earth system, with an average temperature of about minus 85 degrees Celsius (minus 120 degrees Fahrenheit). The very scarce water vapor present at the top of the mesosphere forms noctilucent clouds, the highest clouds in Earth’s atmosphere, which can be seen by the naked eye under certain conditions and at certain times of day. Most meteors burn up in this atmospheric layer. Sounding rockets and rocket-powered aircraft can reach the mesosphere. Thermosphere. Located between about 80 and 700 kilometers (50 and 440 miles) above Earth’s surface is the thermosphere, whose lowest part contains the ionosphere. In this layer, temperatures increase with altitude due to the very low density of molecules found here. It is both cloud- and water vapor-free. The aurora borealis and aurora australis are sometimes seen here. The International Space Station orbits in the thermosphere. Exosphere. Located between about 700 and 10,000 kilometers (440 and 6,200 miles) above Earth’s surface, the exosphere is the highest layer of Earth’s atmosphere and, at its top, merges with the solar wind. Molecules found here are of extremely low density, so this layer doesn’t behave like a gas, and particles here escape into space. While there’s no weather at all in the exosphere, the aurora borealis and aurora australis are sometimes seen in its lowest part. Most Earth satellites orbit in the exosphere. The Edge of Outer Space. While there’s really no clear boundary between where Earth’s atmosphere ends and outer space begins, most scientists use a delineation known as the Karman line, located 100 kilometers (62 miles) above Earth’s surface, to denote the transition point, since 99.99997 percent of Earth’s atmosphere lies beneath this point. A February 2019 study using data from the NASA/European Space Agency Solar and Heliospheric Observatory (SOHO) spacecraft suggests, however, that the farthest reaches of Earth’s atmosphere — a cloud of hydrogen atoms called the geocorona — may actually extend nearly 391,000 miles (629,300 kilometers) into space, far beyond the orbit of the Moon. — Alan Buis/NASA's Global Climate Change website ‹ Back to main article: 'The Atmosphere: Earth's Security Blanket'
  • The Atmosphere: Earth's Security Blanket
    Part One Most of us probably don’t think much about Earth’s atmosphere, let alone how much humans are affecting it. After all, it’s just there. Gazing into the sky during the day, it’s tough to get a handle on what’s happening up there. Our atmosphere seems tantalizingly close and yet mysteriously distant. The life-sustaining air we breathe envelops our planet like a pale-blue security blanket, clinging to us by the force of gravity. We see birds, planes, an ever-changing patchwork of clouds and, in some places, air pollution. Farther out, our Moon glows down on us and a blazing Sun hangs in the sky. From our Earth-bound perspective, it’s hard to tell where our atmosphere ends and space begins. (Our atmosphere is like a multi-layered cake.) Then darkness falls, and through the murky blackness, a portal opens to the heavens, punctuated only by the light of the Moon, stars and cosmos. The descent of night makes sizing up our atmosphere an even more baffling proposition. It’s only when we view Earth from the unique vantage point of space that the true nature of our atmosphere becomes apparent. From Earth orbit, we gain a new window into our planet. Beneath us, the very edge of the atmosphere — known as Earth’s “limb” — appears as a glowing halo of colors; a luminescent layer cake that gradually fades into the blackness of space. And suddenly our atmosphere, which seemed so vast and mysterious from the ground, appears shockingly thin, even fragile. So thought retired NASA astronaut Scott Kelly. As he neared the end of a one-year stay aboard the International Space Station in February 2016, he told CNN, "When you look at the ... atmosphere on the limb of the Earth, I wouldn't say it looks unhealthy, but it definitely looks very, very fragile and just kind of like this thin film, so it looks like something that we definitely need to take care of." Other NASA astronauts have made similar remarks. Indeed, Earth’s atmosphere isn’t something we can take for granted. Without it, life as we know it wouldn’t exist. Not only does it contain the oxygen we need to live, but it also protects us from harmful ultraviolet solar radiation. It creates the pressure without which liquid water couldn’t exist on our planet’s surface. And it warms our planet and keeps temperatures habitable for our living Earth. In fact, Earth’s atmosphere is very thin, with a mass only about one-millionth that of the planet itself. Further, about 80 percent of the atmosphere is contained within its lowest layer, the troposphere, which is, on average, just 12 kilometers (7.5 miles) thick. While there’s no exact boundary line between the atmosphere and space, the accepted standard is about 100 kilometers (62 miles) above Earth’s surface. If you drove that distance on the ground, you might see a change in scenery. But travel that distance straight up, and you’ll quickly find yourself in an environment inhospitable to life. At about 8 kilometers (5 miles) altitude, there’s insufficient oxygen in the air to sustain human life. At around 19 kilometers (12 miles) altitude, your blood boils unless you’re in a pressurized environment. So is Earth’s atmosphere big or small? Is it fragile or robust? Stable or volatile? And how much are humans affecting it, really? The answer, it seems, is all of the above, and we’re affecting it a lot. In this five-part series, we asked several NASA atmospheric scientists to weigh in on the matter. A ‘Radical’ Chemical That Helps Keep Our Atmosphere Stable Before we can determine how fragile or stable Earth’s atmosphere is, we first have to define what those terms mean. So says Kevin Bowman of NASA’s Jet Propulsion Laboratory in Pasadena, California, principal investigator for the Tropospheric Emission Spectrometer (TES) instrument on NASA’s Aura satellite. TES operated from 2004 to early 2018. “The chemistry of Earth’s atmosphere is remarkably stable, providing a relatively safe place for animals and plants to thrive,” said Bowman. “However, even small changes to the quality of the air that we breath can have profound impacts on our health. Understanding that stability, the ways it could be impacted by humans and how it interacts with the broader Earth system are key research tasks in atmospheric chemistry.” Bowman said one key to that stability is the hydroxyl radical (OH), a chemical that plays a central role in the ability of Earth’s atmosphere to cleanse itself of pollutants. One of the most reactive gases in our atmosphere, OH is like a global detergent that helps keep things in balance by removing pollutants from the lower atmosphere. It’s the main check on concentrations of carbon monoxide, sulfur dioxide, hydrogen sulfide, methane and higher hydrocarbons. An animated map of model output of hydroxyl radical (OH) primary production over a 24-hour period in July 2000. The concentration tracks with the movement of sunlight across the globe. Higher levels of OH over populated land are likely from OH recycling in the presence of nitric oxide and nitrogen dioxide, which are common pollutants from cars and industry. Credit: NASA/Julie Nicely Scientists have numerous questions about OH. They want to know how stable it is, how quickly it cleanses these chemicals from the atmosphere, and how the atmosphere’s cleansing capacity has changed in the past and may change in the future. They also want to know how climate change may affect OH’s stability. For example, continued increases in methane — a potent greenhouse gas — will consume OH, resulting in deteriorated air quality. To predict changes in OH’s capacity to cleanse the atmosphere, scientists rely on atmospheric models based on data from satellites, aircraft and ground measurements. “Studies of ancient climates suggest these models are underestimating the sensitivity of OH to climate change,” said Bowman. “As a result, our atmosphere might be more variable than we thought, and OH could end up changing much more rapidly than predicted, with detrimental effects on Earth’s surface air quality, the concentration of greenhouse gases and ozone.” Bowman said quantifying OH has always been challenging for scientists since it can’t be measured directly. In the past, scientists derived estimates of OH by tracking quantities of another trace gas, methyl chloroform, which was widely used in the 1950s as an industrial solvent and was created by bomb blasts during that era. Methyl chloroform only reacts with OH, which slowly destroys it. But methyl chloroform was eventually replaced by other solvents, and over time, its concentrations in the atmosphere have decreased enough that it is no longer useful for estimating OH. Observations from instruments like TES give researchers an alternate approach to estimate OH through atmospheric computer models that produce “chemical weather forecasts.” TES measurements of a number of other chemical elements influenced by OH, such as ozone, carbon monoxide and nitrogen dioxide, have enabled scientists to better represent OH in these models. To date, studies based on TES data show there’s more OH in the northern hemisphere than in the southern hemisphere — consistent with methyl chloroform concentrations — and that OH is sensitive to changes in emissions, especially in the tropics. Data from NASA's Tropospheric Emission Spectrometer on NASA's Aura satellite show the relative concentrations of two atmospheric air pollutants, ozone (seen above) and carbon monoxide (seen in browse view), in January 2006. Credit: NASA Contributions of nitrogen dioxide emissions - the primary source of ozone - to the global average thermal absorption of ozone as observed by the Tropospheric Emission Spectrometer instrument on NASA's Aura spacecraft in Aug. 2006. High values (red) indicate that emissions in that location contribute more strongly to the trapping of heat in Earth's atmosphere relative to other locations. Credit: NASA-JPL/Caltech/CU-Boulder Bowman discussed some of the many other science advances TES has made possible. Its biggest contributions have been in advancing our understanding of ozone in the troposphere. TES data, together with data from other instruments aboard Aura, have significantly improved our understanding of how ozone affects human health, climate and other parts of the Earth system. A 2015 TES study showed how ozone produced in Asia was transported around the world, increasing ozone emissions on the U.S. West Coast, even as U.S. ozone emissions were declining. TES data also helped quantify how ozone in the upper troposphere serves as a greenhouse gas, warming the atmosphere. This information was used to test climate model predictions of ozone’s greenhouse effect, quantifying how regional changes in pollutants that create ozone have altered climate. TES measurements have also improved our understanding of global air quality by documenting increases in tropospheric ozone levels in many regions of the world, such as Asia. Monthly-mean maximum daily 8-hour average background ozone concentration in parts per billion in California and Nevada, estimated by integrating data from NASA's Aura spacecraft. Credit: NASA/JPL-Caltech/George Mason University “We’re beginning to see a redistribution in the emissions of pollutants that form ozone,” Bowman said. “They’re shifting geographically toward the equator, making ozone a more potent greenhouse gas.” Bowman said TES has also given us a window into Earth’s water cycle by measuring so-called “heavy” water molecules, a naturally occurring variant of water that contains more neutrons than normal water molecules and provide clues to how the water evaporated and fell as precipitation in the past. This, in turn, helps scientists understand what controls the amount of water vapor in the atmosphere. A study using these data showed how the Amazon initiates its own rainy season. In addition, TES provided new information about ammonia, a precursor to harmful aerosols; and new measurements of carbon-containing gases such as methane and carbonyl sulfide, giving scientists new insights into the carbon cycle. “TES was a pioneer,” Bowman said. “It collected a whole new set of measurements using new techniques that are now being used by a new generation of instruments.” To learn more about TES, visit https://tes.jpl.nasa.gov/. Next up: 'The Atmosphere: Getting a Handle on Carbon Dioxide'
  • 2019 Arctic Sea Ice Minimum Tied for Second Lowest on Record
    The extent of Arctic sea ice at the end of this summer was effectively tied with 2007 and 2016 for second lowest since modern record keeping began in the late 1970s. An analysis of satellite data by NASA and the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder shows that the 2019 minimum extent, which was likely reached on Sept. 18, measured 1.60 million square miles (4.15 million square kilometers). Arctic sea ice likely reached its 2019 minimum extent on Sept. 18. At 1.60 million square miles (4.15 million square kilometers), this year's summertime extent is effectively tied for the second in the satellite record, according to NASA and the National Snow and Ice Data Center. Credit: NASA/Trent Schindler. This video can be downloaded at NASA's Scientific Visualization Studio. The Arctic sea ice cap is an expanse of frozen seawater floating on top of the Arctic Ocean and neighboring seas. Every year, it expands and thickens during the fall and winter and grows smaller and thinner during the spring and summer. But in the past decades, increasing temperatures have caused marked decreases in the Arctic sea ice extents in all seasons, with particularly rapid reductions in the minimum end-of-summer ice extent. Changes in Arctic sea ice cover have wide-ranging impacts. The sea ice affects local ecosystems, regional and global weather patterns, and the circulation of the oceans. “This year’s minimum sea ice extent shows that there is no sign that the sea ice cover is rebounding,” said Claire Parkinson, a climate change senior scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The long-term trend for Arctic sea ice extent has been definitively downward. But in recent years, the extent is low enough that weather conditions can either make that particular year’s extent into a new record low or keep it within the group of the lowest.” An opening in the sea ice cover north of Greenland is partially filled in by much smaller sea ice rubble and floes, as seen during an Operation IceBridge flight on Sept. 9, 2019. Credit: NASA/Linette Boisvert The melt season started with a very low sea ice extent, followed by a very rapid ice loss in July that slowed down considerably after mid-August. Microwave instruments onboard United States Department of Defense’s meteorological satellites monitored the changes from space. “This was an interesting melt season,” said Walt Meier, a sea ice researcher at NSIDC. “At the beginning of August we were at record low ice levels for that time of the year, so a new minimum record low could have been in the offering. ”But unlike 2012, the year with the lowest ice extent on record, which experienced a powerful August cyclone that smashed the ice cover and accelerated its decline, the 2019 melt season didn’t see any extreme weather events. Although it was a warm summer in the Arctic, with average temperatures 7 to 9 degrees Fahrenheit (4 to 5 degrees Celsius) above what is normal for the central Arctic, events such as this year’s severe Arctic wildfire season or European heat wave ended up not having much impact on the sea ice melt. “By the time the Siberian fires kicked into high gear in late July, the Sun was already getting low in the Arctic, so the effect of the soot from the fires darkening the sea ice surface wasn’t that large,” Meier said. “As for the European heat wave, it definitely affected land ice loss in Greenland and also caused a spike in melt along Greenland’s east coast, but that’s an area where sea ice is being transported down the coast and melting fairly quickly anyway.”
  • Satellite Data Record Shows Climate Change's Impact on Fires
    Hot and dry. These are the watchwords for large fires. While every fire needs a spark to ignite and fuel to burn, the hot and dry conditions in the atmosphere determine the likelihood of a fire starting, its intensity and the speed at which it spreads. Over the past several decades, as the world has increasingly warmed, so has its potential to burn. This visualization shows carbon emissions from fires from Jan. 1, 2003, through Dec. 31, 2018. The color bar reflects the quantity of carbon emitted. Credit: NASA Since 1880, the world has warmed by 1.9 degrees Fahrenheit (1.09 degrees Celsius), with the five warmest years on record occurring in the last five years. Since the 1980s, the wildfire season has lengthened across a quarter of the world's vegetated surface, and in some places like California, fire has become nearly a year-round risk. The year 2018 was California's worst wildfire season on record, on the heels of a devasting 2017 fire season. In 2019, wildfires have already burned 2.5 million acres in Alaska in an extreme fire season driven by high temperatures, which have also led to massive fires in Siberia. Whether started naturally or by people, fires worldwide and the resulting smoke emissions and burned areas have been observed by NASA satellites from space for two decades. Combined with data collected and analyzed by scientists and forest managers on the ground, researchers at NASA, other U.S. agencies and universities are beginning to draw into focus the interplay between fires, climate and humans. "Our ability to track fires in a concerted way over the last 20 years with satellite data has captured large-scale trends, such as increased fire activity, consistent with a warming climate in places like the western U.S., Canada and other parts of Northern Hemisphere forests where fuels are abundant," said Doug Morton, chief of the Biospheric Sciences Laboratory at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Where warming and drying climate has increased the risk of fires, we’ve seen an increase in burning." A Hotter, Drier World High temperatures and low humidity are two essential factors behind the rise in fire risk and activity, affecting fire behavior from its ignition to its spread. Even before a fire starts, they set the stage, said Jim Randerson, an Earth system scientist at the University of California, Irvine who studies fires both in the field and with satellite data. He and his colleagues studied the abundance of lightning strikes in the 2015 Alaskan fire season that burned a record 5.1 million acres. Lightning strikes are the main natural cause of fires. The researchers found an unusually high number of lightning strikes occurred, generated by the warmer temperatures that cause the atmosphere to create more convective systems — thunderstorms — which ultimately contributed to more burned area that year. Hotter and drier conditions also set the stage for human-ignited fires. "In the Western U.S., people are accidentally igniting fires all the time," Randerson said. "But when we have a period of extreme weather, high temperatures, low humidity, then it’s more likely that typical outdoor activity might lead to an accidental fire that quickly gets out of control and becomes a large wildfire." For example, in 2018 sparks flying from hammering a concrete stake into the ground in 100-degree Fahrenheit heat and sparks from a car's tire rim scraping against the asphalt after a flat tire were the causes of California's devastatingly destructive Ranch and Carr Fires, respectively. These sparks quickly ignited the vegetation that was dried out and made extremely flammable by the same extreme heat and low humidity, which research also shows can contribute to a fire's rapid and uncontrollable spread, Randerson said. The same conditions make it more likely for agricultural fires to get out of control. A warming world also has another consequence that may be contributing to fire conditions persisting over multiple days where they otherwise might not have in the past: higher nighttime temperatures. "Warmer nighttime temperature allow fires to burn through the night and burn more intensely, and that allows fires to spread over multiple days where previously, cooler nighttime temperatures might have weakened or extinguished the fire after only one day," Morton said. Climate Systems at Work Hot and dry conditions that precede fires can be tempered by rain and moisture circulating in the atmosphere. On time scales of months to years, broader climate patterns move moisture and heat around the planet. Monitoring these systems with satellite observations allows researchers to be able to begin to develop computer models for predicting whether an upcoming fire season in a given region will be light, average or extreme. The most important of these indicators are sea surface temperatures in the Pacific Ocean that govern the El Niño Southern Oscillation (ENSO). "ENSO is a major driver of fire activity across multiple continents," Randerson said, who along with Morton and other researchers have studied the relationship between El Niño events and fire seasons in South America, Central America, parts of North America, Indonesia, Southeast Asia and equatorial Asia. "The precipitation both before the fire season and during the fire season can be predicted using sea surface temperatures that are measured by NASA and NOAA satellites." An ongoing project, Randerson said, is to now extend that prediction capability globally to regions that are affected by other ocean-climate temperature changes and indicators. The Human Factor In studying the long-term trends of fires, human land management is as important to consider as any other factor. Globally, someplace on Earth is always on fire — and most of those fires are set by people, either accidentally in wildlands, or on purpose, for example, to clear land or burn agricultural fields after the harvest to remove crop residues. But not all fires behave the same way. Their behavior depends on the fuel type and the how people are changing the landscape. While fire activity has gotten worse in northern latitude forests, research conducted by Randerson and Morton has shown that despite climate conditions that favor fires, the number of fires in grassland and savanna ecosystems worldwide are declining, contributing to an overall decline in global burned area. The decline is due to an increased human presence creating new cropland and roads that serve as fire breaks and motivate the local population to fight these smaller fires, Morton said. "Humans and climate together are really the dual factors that are shaping the fires around the world. It's not one or the other," Randerson said. Fire Feedbacks Fires impact humans and climate in return. For people, beyond the immediate loss of life and property, smoke is a serious health hazard when small soot particles enter the lungs. Long-term exposure has been linked to higher rates of respiratory and heart problems. Smoke plumes can travel for thousands of miles affecting air quality for people far downwind of the original fire. Fires also pose a threat to local water quality, and the loss of vegetation can lead to erosion and mudslides afterwards, which have been particularly bad in California, Randerson said. In June and early July 2019, a heat wave in Alaska broke temperature records, as seen in this July 8 air temperature map (left). The corresponding image from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on the Aqua satellite on the right shows smoke from lightening-triggered wildfires. Credit: NASA Earth Observatory For the climate, fires can directly and indirectly increase carbon emissions to the atmosphere. While they burn, fires release carbon stored in trees or in the soil. In some places like California or Alaska, additional carbon may be released as the dead trees decompose, a process that may take decades because dead trees will stand like ghosts in the forest, decaying slowly, Morton said. In addition to releasing carbon as they decompose, the dead trees no longer act as a carbon sink by pulling carbon dioxide out of the atmosphere. In some areas like Indonesia, Randerson and his colleagues have found that the radiocarbon age of carbon emissions from peat fires is about 800 years, which is then added to the greenhouse gases in that atmosphere that drive global warming. In Arctic and boreal forest ecosystems, fires burn organic carbon stored in the soils and hasten the melting of permafrost, which release methane, another greenhouse gas, when thawed. Another area of active research is the mixed effect of particulates, or aerosols, in the atmosphere in regional climates due to fires, Randerson said. Aerosols can be dark like soot, often called black carbon, absorbing heat from sunlight while in the air, and when landing and darkening snow on the ground, accelerating its melt, which affects both local temperatures — raising them since snow reflects sunlight away — and the water cycle. But other aerosol particles can be light colored, reflecting sunlight and potentially having a cooling effect while they remain in the atmosphere. Whether dark or light, according to Randerson, aerosols from fires may also have an effect on clouds that make it harder for water droplets to form in the tropics, and thus reduce rainfall — and increase drying. Fires of all types reshape the landscape and the atmosphere in ways that can resonate for decades. Understanding both their immediate and long-term effects requires long-term global data sets that follow fires from their detection to mapping the scale of their burned area, to tracing smoke through the atmosphere and monitoring changes to rainfall patterns. "As climate warms, we have an increasing frequency of extreme events. It’s critical to monitor and understand extreme fires using satellite data so that we have the tools to successfully manage them in a warmer world," Randerson said.
  • NASA's ECOSTRESS Detects Amazon Fires from Space
    if (typeof captions == 'undefined'){ var captions = []; } captions.push("ECOSTRESS imagery of fires burning in the Bolivian Amazon on Aug. 23, 2019. Red areas show regions hotter than the sensor was designed to measure (approximately 220 degrees Fahrenheit, or 104 degrees Celsius). Dark wispy areas indicate thick smoke. Credit: NASA/JPL-Caltech › Larger view") captions.push("ECOSTRESS imagery of fires burning in the Brazilian Amazon on Aug. 23, 2019. Red areas show regions hotter than the sensor was designed to measure (approximately 220 degrees Fahrenheit, or 104 degrees Celsius). Dark wispy areas indicate thick smoke. Credit: NASA/JPL-Caltech › Larger view") $(document).ready(function(){ var type = "news"; var slider = new MasterSlider(); // adds Arrows navigation control to the slider. slider.control('bullets', {autohide: false}); slider.control('arrows'); homepage_slider_options = { width: $(window).width(), // slider standard width height: 400, // slider standard height layout: "autofill", space:5, fullwidth: true, autoHeight: false, //will expand to height of image autoplay: false, speed: 20, loop: true, instantStartLayers: true //disable to allow for layer transitions }; slider.setup('masterslider_1423' , homepage_slider_options); if (type == "news"){ slider.api.addEventListener(MSSliderEvent.CHANGE_START , function(){ $('.slider_caption').html(captions[slider.api.index()]); }); } }); NASA's Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) captured imagery of fires in the Amazon regions of Brazil and Bolivia on Aug. 23, 2019. The red areas in the images - in eastern Bolivia and northern Brazil - are where surface temperatures exceeded the maximum measurable temperature of the instrument's sensor (approximately 220 degrees Fahrenheit, or 104 degrees Celsius), highlighting the burning areas along the fire fronts. The dark, wispy areas indicate thick smoke - thick enough to obscure much of the fire from view. The measurements cover areas of about 77 by 77 yards (70 by 70 meters) each, or about the size of a football field. The primary mission of ECOSTRESS is to measure the temperature of plants from the vantage point of the International Space Station. However, it can also detect other heat-related phenomena like heat waves, volcanoes and fires. Due to the space station's unique orbit, ECOSTRESS acquires imagery of the same areas at different times of day as it passes by overhead - instead of crossing over each area at the same time of day like satellites in some other orbits do. This is particularly important when trying to acquire cloud-free imagery over perennially cloudy areas like the Amazon. ECOSTRESS launched to the space station on June 29, 2018. NASA's Jet Propulsion Laboratory in Pasadena, California, built and manages the ECOSTRESS mission for the Earth Science Division in the Science Mission Directorate at NASA Headquarters in Washington. ECOSTRESS is an Earth Venture Instrument mission; the program is managed by NASA's Earth System Science Pathfinder program at NASA's Langley Research Center in Hampton, Virginia. More information about ECOSTRESS is available here: https://ecostress.jpl.nasa.gov News Media Contact Esprit Smith Jet Propulsion Laboratory, Pasadena, Calif. 818-354-4269 esprit.smith@jpl.nasa.gov
  • Landsat Illustrates Five Decades of Change to Greenland Glaciers
    Ice fronts have retreated, rocky peaks are more exposed, fewer icebergs drift to the ocean: the branching network of glaciers that empty into Greenland’s Sermilik Fjord has changed significantly in the last half-century. Comparing Landsat images from 1972 and 2019, those changes and more come into view. // 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(); }); }); Southeastern Greenland Glaciers Glaciers in southeastern Greenland, including (from left to right) Helheim, Fenris and Midgard, are seen in a Landsat 8 image from Aug. 12, 2019 (right image), and a composite image from Landsat 1 scenes collected in September 1972 (left image). Comparing images across the span of the Landsat mission provides a record of almost five decades of change to this region. Credit: NASA/Christopher Shuman The glaciers appear brownish grey in this true-color Landsat 8 satellite image from Aug. 12, 2019. The color indicates that the surface has melted, a process that concentrates dust and rock particles and leads to a darker recrystallized ice sheet surface. The darker melt surface in 2019 extends much farther onto the ice sheet than it did in 1972, when the first Landsat satellite gathered data on the area, said Christopher Shuman, a glaciologist with the University of Maryland, Baltimore County, at NASA Goddard Space Flight Center in Greenbelt, Maryland. Landsat is a joint mission of NASA and the U.S. Geological Survey. Helheim Glacier, one of the largest and fastest flowing of its kind in Greenland, has retreated approximately 4.7 miles (7.5 kilometers) up a wide fjord in the time between the two scenes, leaving a jumble of sea ice where its calving front used to be. To the east, Midgard Glacier has retreated approximately 10 miles (16 kilometers), splitting into two branches farther up the fjord. Changes to the rocky outcrops of the area’s mountains and smaller tributary glaciers are also visible by comparing the two Landsat images. // 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(); }); }); The Helheim Glacier The Helheim Glacier is seen in a close-up of the images above. One of the largest glaciers in Greenland, Helheim has retreated approximately 4.7 miles (7.5 kilometers) between when these Landsat scenes were collected in 1972 (left image) and 2019 (right image). As the glacier lost ice over the last 47 years, the cliff walls along the glacier and the rocky outrcrops in the middle become more exposed. Credit: NASA/Chris Shuman “There’s a lot more bare rock visible now, which used to be covered with ice,” Shuman said. “And all these little glaciers are all getting slammed, as well as the bigger ones like Helheim, Fenris and Midgard. There are scores of examples of change just in this one area.” In a close-up of the Helheim Glacier, a patch of open water is visible right at the calving front. Three days after Landsat 8 collected the image over Helheim and its neighboring glaciers, NASA’s Oceans Melting Greenland (OMG) project flew over that open patch of water in an airplane and dropped a temperature-measuring probe that detected warm water at the ice front. OMG is examining how oceans melt glaciers from below, even as air temperatures warm the ice from above. NASA’s Oceans Melting Greenland campaign flew over a region of open water at the calving front of Helheim Glacier on Aug. 15, 2019, dropping a temperature probe that detected warm water. The open water is visible in the 2019 Landsat image above. Credit: NASA /Josh Willis Unusually warm air temperatures this summer have caused record melt across Greenland. Approximately 90 percent of the surface of Greenland’s ice sheet melted at some point between July 30 and Aug. 2, during which time an estimated 55 billion tons of ice melted into the ocean, according to the National Snow and Ice Data Center. Shuman also tracked the unusually warm weather at the top of the Greenland Ice Sheet, 10,550 feet (3,216 meters) above sea level, where temperatures were above freezing for more than 16.5 hours total during July 30 and 31.
  • NASA's AIRS Maps Carbon Monoxide from Brazil Fires
    New data from NASA's Atmospheric Infrared Sounder (AIRS) instrument, onboard the Aqua satellite, show the movement high in the atmosphere of carbon monoxide associated with fires in the Amazon region of Brazil. This time series maps carbon monoxide at an altitude of 18,000 feet (5,500 meters) from Aug. 8 to 22, 2019. As the series progresses, the carbon monoxide plume grows in the northwest Amazon region then drifts in a more concentrated plume toward the southeastern part of the country. Each "day" in the series is made by averaging three days' worth of measurements, a technique used to eliminate data gaps. Green indicates concentrations of carbon monoxide at approximately 100 parts per billion by volume (ppbv); yellow, at about 120 ppbv; and dark red, at about 160 ppbv. Local values can be significantly higher. A pollutant that can travel large distances, carbon monoxide can persist in the atmosphere for about a month. At the high altitude mapped in these images, the gas has little effect on the air we breathe; however, strong winds can carry it downward to where it can significantly impact air quality. Carbon monoxide plays a role in both air pollution and climate change. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), senses emitted infrared and microwave radiation from Earth to provide a three-dimensional look at Earth's weather and climate. With more than 2,000 channels sensing different regions of the atmosphere, the instruments create a global, three-dimensional map of atmospheric temperature and humidity, cloud amounts and heights, greenhouse gas concentrations and many other atmospheric phenomena. The AIRS and AMSU instruments are managed by NASA's Jet Propulsion Laboratory in Pasadena, California, under contract to NASA. JPL is a division of Caltech. More information about AIRS can be found at: https://airs.jpl.nasa.gov News Media Contact Esprit Smith Jet Propulsion Laboratory, Pasadena, Calif. 818-354-4269 esprit.smith@jpl.nasa.gov
  • Boreal Forest Fires Could Release Deep Soil Carbon
    Increasingly frequent and severe forest fires could burn generations-old carbon stored in the soils of boreal forests, according to results from the Arctic-Boreal Vulnerability Experiment (ABoVE) funded by NASA’s Earth Science Division. Releasing this previously buried carbon into the atmosphere could change these forests’ balance of carbon gain and loss, potentially accelerating warming. As Arctic summers get warmer and drier, boreal forest fires are becoming more intense, meaning they burn deeper into the soil. Researcher Xanthe Walker and her team investigated whether the 2014 fires in Canada’s Northwest Territories burned deep enough to release older carbon that is normally stored and protected in the soil. Credit: NASA / Jefferson Beck Canada’s Northwest Territories were scorched by record-breaking wildfires in 2014. The team of researchers from the United States and Canada took soil samples from more than 200 locations in the region. They found that for old forests (more than 70 years old) and forests in wet locations, a thick layer of organic matter in the soil protected the oldest carbon, called “legacy carbon,” that was not burned in previous cycles of burn and regrowth. However, in younger, drier forests, the shallower soil organic matter layer allowed fires to reach the legacy carbon, releasing it into the atmosphere. As Earth’s northern regions grow warmer and drier due to climate change, fire seasons are getting longer and fires are becoming more severe. Boreal forests have long been thought to absorb more carbon from the atmosphere than they release into it, making them carbon “sinks.” But if bigger and more frequent fires start burning legacy carbon, these forests could start releasing more carbon than they store. Carbon dioxide is a greenhouse gas, so releasing more of it into the atmosphere could affect the balance of the global carbon cycle and contribute to climate change. Boreal forests are located in the northernmost regions of North America, Europe and Canada, and contain spruce, fir, pine, larch, aspen and birch trees. These forests store 30 percent to 40 percent of all land-based carbon in the world, and most of that carbon is found in the soils. Soil-based carbon includes soil microbes; plant material made up of dead leaves, branches and stems; and both living and dead roots, as well as burned material from previous fires. During intense fires, the organic material that contains the soil carbon can burn along with trees and plants. Older carbon deeper in the soil does not always burn in a fire, but can stay protected in the soil. The researchers called this “legacy carbon.” After observing the intensity of the 2014 fires, the team wondered if these pools of legacy carbon were at risk. “Carbon accumulates in these soils like tree rings, with the newest carbon at the surface and the oldest carbon at the bottom,” said senior author Michelle Mack, a professor at Northern Arizona University’s Center for Ecosystem Science and Society. “We thought we could use this layering to see how far back in time, in the history of the forest, fires were burning.” The team measured the age of the trees, how deep in the soil the fire burned, how moist the sampled area was, and the depth of the topmost soil organic layer, composed of plant and animal matter. They also used radiocarbon dating of the soils to determine if the legacy carbon pools burned in the fire. The team found that wetter forests and those less than 60 years old were more likely to contain legacy carbon than older, drier forests. But the ones most likely to lose that legacy carbon were the young forests in drier areas. These forests were less likely to have accumulated enough organic matter to protect the older carbon between previous fires and the 2014 fire. Almost half of the plots under 60 years old lost legacy carbon, while just one older plot did. In total, about 12 percent of the forests that burned in the 2014 fires met the criteria for being vulnerable to legacy carbon loss. The researchers estimate that these forests released about 8.8 million tons of carbon as they burned, compared to the nearly 104 million tons released by all the fires. The team said their results show that in order to understand the effects of future fires on Canada’s boreal forests and the global carbon cycle, researchers must account for legacy carbon loss. “By defining and analyzing ‘legacy carbon,’ this paper offers a new way to think about long-sequestered carbon stocks in boreal forests and how vulnerable they are to being burned during increasingly frequent and severe wildfires,” said Brendan Rogers, a scientist at Woods Hole Research Center who co-authored the Nature study. “This tool helps us understand when burning goes ‘outside the norm’ from a historical perspective and begins to combust carbon stocks that survived past fires.” If wildfires do become more frequent, they could increase the number of young forests vulnerable to burning and legacy carbon loss, they added. The research team sampled more than 200 plots in the forests of Canada’s Northwest Territories to see whether “legacy” carbon left over from previous fire cycles was threatened by the intense 2014 fires. They found that forests less than 60 years old and located in drier climates had a higher risk of losing legacy carbon in the fires than older, wetter forests. Credit: NASA / Xanthe Walker, Center for Ecosystem Science and Society at Northern Arizona University “In older stands that burn, legacy carbon is protected by thick organic soils,” said Xanthe Walker, lead author and postdoctoral researcher at the Center for Ecosystem Science and Society at Northern Arizona University. “But in younger stands that burn, the soil does not have time to re-accumulate after the previous fire, making legacy carbon vulnerable to burning. This pattern could shift boreal forests into a new domain of carbon cycling, where they become a carbon source instead of a sink.” NASA’s ABoVE campaign supports research using remote sensing, airborne measurements and field investigations to understand climate change’s impacts on Alaska and northern Canada. The Arctic is changing faster than anywhere else on Earth, and ABoVE studies track shifting coastlines, changing plant growth patterns and greenhouse gas emissions from thawing permafrost and boreal forest fires. To learn more about the Arctic Boreal Vulnerability Experiment, visit https://above.nasa.gov/.

Copyright © 2019 Gail Chord Schuler. All Rights Reserved.