NASA last week that both the 91爆料 STRIVE team and the 91爆料-affiliated EDGE team were selected to lead satellite missions to better understand Earth and improve capabilities to foresee environmental events and mitigate disasters.

STRIVE and EDGE were among four finalists as part of the agency鈥檚 Earth System Explorers Program, which conducts principal investigator-led space science missions as recommended by the National Academies of Sciences, Engineering, and Medicine 2017 Decadal Survey for Earth Science and Applications from Space.

The total estimated cost of each mission, not including launch, will not exceed $355 million with a mission launch date of no earlier than 2030, stated NASA.

鈥淭his was fantastic news. We have been working on this concept for a few years now, and for many of us it is a dream come true. To be able to observe the atmosphere at this level of detail is a tremendous opportunity,鈥� said , a 91爆料 professor of atmospheric and climate science, who is leading the STRIVE mission.

Stratosphere-Troposphere Response using Infrared Vertically-resolved light Explorer

, which stands for Stratosphere-Troposphere Response using Infrared Vertically-resolved light Explorer, will examine the regions of the atmosphere where weather forms and the ozone layer sits, yielding new insights into temperature and trace gases in the atmosphere that affect aviation, long-range transport of volcanic smoke and air pollution.

The STRIVE instruments, compact enough to fit into the trunk of a midsize SUV, can make more than 400,000 observations each day. Instead of looking straight down at the Earth, like other missions, the STRIVE instruments angle sideways towards Earth鈥檚 surface to capture the atmosphere in greater detail.

鈥淲ith these observations, we won鈥檛 just get measurements of ozone but rather all the chemical species that affect ozone in the stratosphere,鈥� Jaegl茅 said.

The ozone layer, which absorbs ultraviolet radiation, after severe depletion in the early 2000s, but still requires careful monitoring.

STRIVE represents a technological and scientific quantum leap that will help researchers understand how air pollution circulates following a wildfire or volcanic eruption, for example. Importantly, STRIVE will also aid weather forecasting efforts beyond the typical 10-day window to give people time to prepare for extreme weather events.

鈥淚f we can see something propagating from high up 鈥� such as large shifts in winds 鈥斅爐hen we will know that several weeks later it will impact Earth鈥檚 surface. Our current weather models cannot predict this connection very well because we don鈥檛 really know what is going on at the interface of the stratosphere and troposphere,” Jaegl茅 added.

The national-scale team includes partners from academia, industry and federal science labs. at the University of Iowa is the deputy principal investigator of STRIVE, and at NASA鈥檚 Goddard Space Flight Center is the project scientist. Several NASA Goddard scientists are also involved. Other 91爆料 members of STRIVE are professor , assistant professor and affiliate faculty member , all in the 91爆料 Department of Atmospheric and Climate Science.

The Earth Dynamics Geodetic Explorer聽

, or Earth Dynamics Geodetic Explorer, uses lasers to observe the three dimensional structure of Earth鈥檚 surface 鈥� including forests, glaciers, ice sheets and sea ice 鈥� as it changes. , a senior principal physicist and , a senior research scientist both at the 91爆料 and , a 91爆料 associate professor of civil and environmental engineering, are part of the EDGE team, led by from Scripps Institution of Oceanography at the University of California San Diego.

EDGE will be the first global satellite imaging laser altimeter system, according to . The system captures surface detail in high resolution by firing laser pulses at the Earth and recording how long it takes for them to return, making over 150,000 measurements each second. It can also precisely track changes in surface elevation over time to capture how ice sheets and glaciers are responding to climate change over seasonal and longer-term timescales.

“What’s really exciting about EDGE is the level of detail it will measure. Older laser altimetry measurements sample a coarse grid of points on the ground, but with the EDGE data we will be able to see individual trees around Seattle, and small cracks in glaciers in Greenland and Antarctica. Often, it’s the fine-scale processes that drive how the large-scale system changes,” Smith said.

Although the effort will focus on polar regions, forests and coastlines, EDGE is an 鈥渆verything mission,鈥� Shean said.

鈥淭hese precise surface elevation change measurements are essential for so many pressing scientific and engineering applications,鈥� he added. 鈥淭he EDGE data will have implications for sea level rise, natural hazards monitoring, water resource and forest management, and wildfire response. This is also a major milestone for 91爆料, as it formalizes 91爆料 leadership and involvement on not one, but two NASA Earth Observation missions. I鈥檓 excited to bring students onto the EDGE team and train the next generation of 91爆料 researchers who will do amazing things with EDGE data in the coming decades.鈥�

For more information on STRIVE, contact Jaegl茅 at jaegle@uw.edu.

A project led by the 91爆料 to better understand our atmosphere鈥檚 complexity is a finalist for NASA鈥檚 next generation of Earth-observing satellites. The space agency this week the projects that will each receive $5 million to advance to the next stage and conduct a one-year concept study.

seeks to better understand the troposphere that we inhabit and the stratosphere above it, where the ozone layer is, as well as the interface where these two layers meet. That interface, about 6 miles (10 kilometers) above the surface, is where important atmospheric chemistry, circulation and climate processes occur.

In addition to STRIVE, two other teams among the finalists also include researchers from the 91爆料.

The four teams that reached the proof-of-concept stage will spend the next year refining their proposals. NASA will then review the concept study reports and select two for implementation. Projects that reach the final stage will have a budget of up to $310 million to build the instruments, which NASA will launch into orbit in 2030 or 2032. The satellites are expected to have an initial working life of two to three years.

, professor of atmospheric sciences at the 91爆料, is principal investigator of STRIVE, or 鈥淪tratosphere Troposphere Response using Infrared Vertically-Resolved Light Explorer.鈥� The national-scale team includes partners from academia, industry and federal science labs.

The two instruments aboard the STRIVE spacecraft would observe temperature, ozone, water vapor, methane, reactive gases, smoke and other aerosol particles. They will collect 400,000 sets of observations every day 鈥� hundreds to thousands of times more than what鈥檚 possible now. Instead of looking straight down at the Earth, the STRIVE instruments point at an angle to Earth鈥檚 surface, allowing them to capture the atmospheric layers in greater detail.

These observations could help to monitor how the UV-absorbing ozone layer is rebuilding or deteriorating in the atmosphere; how smoke particles from volcanoes, wildfires or human emissions travel through the atmosphere and influence air quality; and how water vapor, ozone, and high-elevation clouds influence the climate system.

The STRIVE system would also support longer-range weather forecasts.

鈥淏efore a major weather event at the surface, there can be precursor signs that happen in the stratosphere,鈥� Jaegl茅 said. 鈥淎nd we see those weeks ahead of time. Observing the stratosphere and how these signals propagate down will be key to getting better weather forecasts on subseasonal to seasonal scales, so two weeks to two months in advance.鈥�

As several NASA satellites of their working lifetimes, the agency is looking for future possibilities to continue their legacy of tracking Earth鈥檚 changes.

鈥淔or observing the Earth, before we’ve had these multibillion-dollar instruments and platforms that take much longer to design and to put in operation. I think the overall idea is to move to a nimbler, faster set of satellite missions that will be designed more quickly and cost less,鈥� Jaegl茅 said. 鈥淣ASA will still pursue the bigger missions, but these smaller missions are another tool that they鈥檙e moving forward with.鈥�

at the University of Iowa is the deputy principal investigator of STRIVE, and at NASA鈥檚 Goddard Space Flight Center is the project scientist. Several NASA Goddard scientists are also involved. Other 91爆料 members of STRIVE are professor , assistant professor and affiliate faculty member , all in the 91爆料 Department of Atmospheric Sciences.

Other institutions include the Pacific Northwest National Laboratory, the Lawrence Livermore National Laboratory, the National Center for Atmospheric Research, NorthWest Research Associates, Science Systems and Applications, NASA鈥檚 Goddard Institute for Space Studies, the University of Colorado-Boulder, the University of Toronto and Morgan State University.

The STRIVE team will spend the next year developing a report with an in-depth engineering, cost and technical analysis.

鈥淚t鈥檚 extremely exciting. This was a team effort, with many people involved,鈥� Jaegl茅 said. 鈥淎lso a bit daunting because the next year will be a very busy one, but very exciting for how to make these concepts become a reality.鈥�

Two other projects among the four finalists also involve 91爆料 scientists

The proposal, led by the University of California, San Diego, proposes a new laser instrument to measure the height of vegetation, glaciers and polar ice sheets.

鈥淭he current state-of-the-art for satellite laser altimetry, the satellites that measure surface height, is ICESat-2, which has six laser beams. GEDI, on the International Space Station, has eight beams. EDGE will have 40 laser beams, so the level of detail is just much, much higher,鈥� said , a research scientist at the 91爆料 Applied Physics Laboratory who鈥檚 a member of the ICESat-2 science team and is an investigator on the EDGE proposal.

The EDGE satellite would collect data for the world鈥檚 forests with the ability to resolve individual trees. Unlike existing satellites it would span all latitudes, from the boreal forests to the equator, surveying dense rainforests to sparser temperate woodlands. EDGE would also observe polar ice sheets and glaciers worldwide, including in the Western U.S., Alaska and the Himalayas, where populations rely on meltwater for hydropower, agriculture and household use.

鈥淚t’s very nimble, so it can be off-pointed to collect very dense 3D measurements over priority areas,鈥� said , a 91爆料 assistant professor of civil and environmental engineering who is also involved with EDGE. 鈥淪o for example, we could scan the entire Nisqually Glacier on Mount Rainier, and potentially many other Pacific Northwest glaciers, in a single pass.鈥�

STRIVE science team member Alex Turner is also a member of the proposal led by CalTech and NASA鈥檚 Jet Propulsion Laboratory. Carbon-I would sample carbon dioxide and methane gases, tracking both emissions and sinks in places like the Amazon rainforest. It would have a global resolution of 300 meters, or about the length of three football fields, and could zoom in to a resolution of just 100 feet (30 meters) to investigate particular sources.

鈥淲e suspect that for methane in particular there are 鈥榮uperemitters,鈥� or a small number of sources that emit massive amounts of methane,鈥� Turner said. 鈥淔rom a regulatory perspective, if you can find and fix those superemitters in a timely manner, you can cut your emissions by a pretty large amount.鈥�

The awards are part of NASA鈥檚 new Earth System Explorers Program. The other finalist proposal is , led by the University of California, San Diego.

鈥淎s we continue to confront our changing climate, and its impacts on humans and our environment, the need for data and scientific research could not be greater,鈥� said Nicky Fox, associate director at NASA headquarters. 鈥淭hese proposals will help us better prepare for the challenges we face today, and tomorrow.鈥�

For more information on STRIVE, contact Jaegl茅 at jaegle@uw.edu.

The air in the United States is much cleaner than even a decade ago. But those improvements have come mainly in summer, the season that used to be the poster child for haze-containing particles that cause asthma, lung cancer and other illnesses.

A led by the 91爆料 shows why winter air pollution levels have remained high, despite overall lower levels of harmful emissions from power plants and vehicles throughout the year.

“In the past 10 years or so, the summer air pollution levels have decreased rapidly, whereas the winter air pollution levels have not. Air quality in summer is now almost the same as in winter in the eastern U.S.,” said corresponding author , who did the work as part of his 91爆料 doctorate in atmospheric sciences. “We have pinpointed the chemical processes that explain the seasonal difference in response to emissions reductions.”

The study, published the week of July 23 in the Proceedings of the National Academy of Sciences, shows that the particles follow different pathways in the winter.

Results came from analyzing observations collected during the 2015 (WINTER) campaign. During that 91爆料-led effort, researchers spent six weeks in winter flying through pollution plumes over New York City, Baltimore, Cincinnati, Columbus, Pittsburgh, Washington, D.C., and along the coal-fired power plants of the Ohio River Valley.

The study was funded by the National Science Foundation, with in-kind support from NASA and the National Oceanic and Atmospheric Administration.

Particles that form smog come in different flavors. Two important ones are sulfates, from sulfur dioxide emitted mainly by coal-fired power plants, and nitrates, created from nitrogen oxides known collectively as NOx. Air-quality regulations have lowered sulfur dioxide in the U.S. by 68 percent between 2007 and 2015, and NOx by about a third during that time.

Summertime levels of particulates 鈥� when the two flavors of oxides clump up into watery packets of nitrates and sulfates that create beautiful sunsets but harm human health 鈥� have dropped in the eastern U.S. by about a third during that time. But the winter concentrations of particulates have decreased by only half as much, for reasons that had been unclear.

“The air quality models that we use to understand the origin of air pollution perform quite well in summer, but have some issues in the wintertime. Before this study, we could not reproduce the observed particulate composition in winter,” said , who was second author on the paper and co-principal investigator of the field campaign. “We now have a better tool to look at what is the best strategy to improve wintertime air quality on regional scales in the eastern U.S., and potentially other places, like Europe and Asia.”

In the summer, some of the emitted NOx and sulfur dioxide remains in the gas phase and gets zapped by sunlight or deposited on land, and the rest forms particulates in the form of nitrates and sulfates. As the primary ingredients drop, so do the levels of particulates.

But the new analysis shows that the chemistry of wintertime air follows a more complex path. With less sunlight and colder temperatures, more of the chemistry happens in the liquid phase, on the surfaces of existing particulates or liquid and ice clouds. In that phase, as the primary ingredients drop, the efficiency of converting sulfur dioxide to sulfate rises, because more oxidants are available. And as sulfate goes down, the particulates become less acidic, making NOx convert more easily to nitrates.

So, even though air quality regulations have reduced both types of primary emissions, the total amount of particulates that harm human health has dropped more slowly.

“It’s not that the reductions aren’t working. It’s just that the reductions have a cancelling effect, and the cancelling effect has a set strength,” said Shah, who is now a postdoctoral researcher at Harvard University. “We need to make further reductions. Once the reductions become larger than the cancelling effect, then winter will start behaving more like summer.”

The study predicts that unless emissions reductions outpace current forecasts, air quality in winter will continue to improve only gradually until at least 2023. At this rate it would be several years before emissions reach levels when wintertime pollution starts to drop more quickly.

“This paper shows that understanding the underlying atmospheric chemistry that converts primary pollutants into fine particulate matter is critical for calibrating our expectations about what emissions reductions will accomplish, and therefore for how to optimize future emissions reductions to continue getting the ‘biggest bang for the buck’ in terms of reducing fine particulate matter concentrations,” said third author , who was the principal investigator on the field campaign.

The findings suggest that more emissions reductions, of both sulfur and nitrogen oxides, will be needed to improve wintertime air quality in the Eastern U.S. and other cold climates.

“This research helps explain why emissions controls to reduce air pollution substances, such as sulfate and nitrate, have not been as successful as expected in the eastern U.S. in winter,” said Sylvia Edgerton, program director in the NSF’s Division of Atmospheric and Geospace Sciences, which funded the research. “The WINTER field campaign produced a unique set of winter observations. They demonstrate that chemical feedbacks during winter months counteract expected reductions in air pollution due to reduced emissions.”

Other co-authors are and at the 91爆料; Jason Schroder, Pedro Campuzano-Jost, and Jose Jimenez at the University of Colorado Boulder; Hongyu Guo and Rodney Weber at Georgia Institute of Technology; Amy Sullivan at Colorado State University; Jaime Green, Marc Fiddler and Solomon Bililign at North Carolina A&T State University; Teresa Campos, Meghan Stell, Andrew Weinheimer and Denise Montzka at the National Center for Atmospheric Research in Boulder; and Steven Brown at the National Oceanic and Atmospheric Administration in Boulder.

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For more information, contact Shah at 412-736-0062 聽or vshah@uw.edu, Jaegle at 206-685-2679 or jaegle@uw.edu and Thornton at 206-543-4010 or joelt@uw.edu.

NSF grants: AGS-1360745, AGS-1360834, AGS-1360730. NASA: NNX15AT96G

A 91爆料 atmospheric scientist is leading a scientific effort to study the evolution of air particles in the eastern U.S. in the winter. The six-week is sampling emissions through mid-March from their source to farther out in the environment, at all times of day and the long winter nights.

“We hope to better understand the fate of pollutants and their impact on the global atmosphere during wintertime,” said lead investigator , a 91爆料 professor of atmospheric sciences.

The project is measuring pollution from New York City south to Atlanta, over the coal-fired power plants of the Ohio River Valley, and in the more temperate southeastern U.S., and looking at what happens as those pollutants are blown offshore. Measurements are from a C-130 military transport plane owned by the National Science Foundation and operated for research by the National Center for Atmospheric Research.

The team is based out of a hangar at the NASA Langley Research Center in Hampton, Virginia, through March 15.

Observations include the amount and spatial pattern of the winter emissions, the timescale for them to be converted to other molecules such as ozone, or smog, as well as small particulates 鈥� the form of pollution most hazardous to health 鈥� and how those evolve over time.

The findings will be relevant for other densely populated places.

“This is directly applicable to emissions and transport of pollutants in any region that experiences shorter days, longer nights and colder temperatures during the winter,” Thornton said.

Running the flights during winter presents some challenges.

“In winter, pollution over land often stays close to the ground,” Thornton said. To sample these layers the group is conducting “missed approach” maneuvers in which an airport gives permission for the aircraft to come close to landing, about 100 feet from the ground, and then swoop back up while collecting measurements.

Low winter clouds are also an issue.

“If clouds extend too close to the water’s surface they prevent the pilots from flying visually,” Thornton said, “and we don’t have a way to know whether the clouds are too low until we fly out to look.”

The on the plane include a machine developed by Thornton’s group that takes precise chemical measurements several times a second. 91爆料 graduate student and postdoctoral fellow are operating the instrument during the flights. 91爆料 graduate student and 91爆料 meteorologist analyze atmospheric forecasts to determine the best conditions to fly.

Co-principal investigator , a 91爆料 professor of atmospheric sciences, helped with the flight plans in the first two weeks of February and participated in two of the surveys so far. The winter storms hitting the Northeast have postponed some of the research flights, she said, but the team has planned for some inevitable weather delays.

“The short daylight hours, cold temperatures and ground snow cover lead to different types of chemical reactions in the winter atmosphere compared with summer. In particular, nighttime chemistry plays a much more important role,” Jaegl茅 said.

“We don’t have that much information about what is going on in the winter,” she added. “This will bring a wealth of information in terms of the transformation of pollutants.”

The findings can be used to help regulate emissions and predict air quality during the winter months.

These measurements will complement a recent , in which 91爆料 and other scientists sampled the air over the same region in June and July of 2013.

The current campaign is funded by the National Science Foundation and the National Oceanic and Atmospheric Administration, and supported by the National Center for Atmospheric Research. Other are from NOAA, the University of Colorado the University of California, Berkeley, and Georgia Institute of Technology. Other partners are the University of New Hampshire, the University of Maryland, Baltimore County and the North Carolina Agricultural and Technical State University.

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聽For more information, contact Thornton at joelt@uw.edu and Jaegl茅 at 206-685-2679 or jaegle@uw.edu.

The six-week , through July 15, includes scientists from more than 30 different institutions. Together they are studying how pollutants combine with natural vegetation emissions to affect climate and air quality in the Southeastern U.S.

Despite some thunderstorms the campaign is going well, said , an atmospheric sciences professor at 91爆料 Bothell. He is coordinating air measurements aboard a C-130 military transport plane operated by the National Science Foundation and the National Center for Atmospheric Research.

“We’re getting some very exciting data,” Jaffe said.

Flights out of Smyrna, Tenn., have gone as far as eastern Texas and central Pennsylvania, and above the coal-fired power plants of the Ohio River Valley. This week flights will go to the Atlantic coast and down to the Gulf of Mexico.

Jaffe leads a group conducting the first airborne survey of mercury emissions from U.S. coal plants. The multi-institutional team is deploying new instruments that can measure different forms of mercury from the ground all the way up into the upper atmosphere. Researchers hope to learn how to model mercury levels and forecast the effects of regulations.

“There鈥檚 a lot of uncertainty in the sources of mercury 鈥� where it comes from and how it gets into the ecosystems,” Jaffe said. “If you don鈥檛 have a good handle on the sources of mercury in your tuna fish, it鈥檚 hard to get a handle on the regulations.”

At the research base outside Nashville, , a 91爆料 professor of atmospheric sciences, has been running weather and pollution forecasts to help the team decide a few days beforehand where and when to fly to sample different kinds of air. Depending on the day the team may be sampling pollution plumes above cities such as Houston or Birmingham, Ala., or clean sea air.

In recent years Jaegl茅 has developed theoretical models of how mercury moves from its source, reacts in the atmosphere and eventually ends up in the oceans and in the rain.

“But we have had very few observations,” Jaegl茅 said. “Now with these direct aircraft observations we can start questioning the theory and figure out what processes are missing, and what processes are correct.”

Meanwhile , a 91爆料 associate professor of atmospheric sciences, is studying the dark side of molecules that give boreal forests their distinctive pine scent. On hot, sunny days the nitrogen oxides from tailpipes and smoke stacks react with those pine-scented molecules to produce ground-level ozone, otherwise known as smog.

Plant emissions and pollution also can combine to form light-colored aerosols that reflect sunlight. Some people think this explains why the Southeast has experienced less warming in recent decades than the rest of the country.

A device developed in Thornton’s lab is flying on the P-3 “hurricane hunter” military aircraft operated by the National Oceanic and Atmospheric Administration. A second identical instrument sits at a forest field station in Centreville, Ala. Both capture precise measurements of vegetation particles, pollution, and combinations of the two.

Thousands of chemical reactions make particles appear or disappear, Thornton said. Understanding even one of those compounds requires a broad approach.

“The more variables that are measured simultaneously, the better,” Thornton said. “Large, collaborative field campaigns, where many meteorological and chemical variables are measured together, are the best way to make progress.”

Other research groups this summer are collecting measurements on the ground, taking simultaneous measurements with two smaller planes, and using a 150-foot-tall structure to sample within and above the forest canopy.

“I’m sure this will lead to many years of research, analyzing all these different measurements that we will have collected,” Jaegl茅 said.

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For more information, contact Jaffe at 425-352-5357 or djaffe@uw.edu, Jaegl茅 at 206-685-2679 or 箩补别驳濒茅蔼耻飞.别诲耻, and Thornton at 206-543-4010 or joelt@uw.edu.