NCAR

Space weather warnings could arrive earlier with NCAR coronagraph

March 22, 2017 | A research instrument atop the Mauna Loa volcano in Hawaii could be used to provide earlier warnings to astronauts when dangerous high-energy particles are blasted out of the Sun's corona. The K-Coronagraph (K-Cor), owned and operated by the National Center for Atmospheric Research (NCAR), could flag these space weather events nearly 20 minutes faster than coronagraphs based in space, according to a new, NASA-led study. Coronagraphs use a disk to block the blinding light of the Sun's face in order to create an artificial solar eclipse, enabling scientists to study the very dim solar atmosphere known as the corona.The K-Cor instrument installed at the Mauna Loa Solar Observatory.  (©UCAR. Courtesy of the High Altitude Observatory. This image is freely available for media & nonprofit use.)"While there are lots of advantages to having a coronagraph in space — above the clouds and the distortion of Earth's atmosphere — there are also important advantages to having a coronagraph on the ground," said Joan Burkepile, a co-author of the study and a scientist at NCAR's High Altitude Observatory.Ground-based instrumentation costs a fraction of space-based hardware, and images can be acquired more frequently (seconds compared to minutes) and then distributed in near real time. K-Cor is also the only coronagraph that is observing the low corona in white light. This allows it to detect the very early stages of the solar activity that drives space weather.Elements of a space weather warning There are several types of space weather events originating on the Sun that can produce impacts on Earth. The new paper, published in the journal Space Weather, examines solar energetic particles (SEPs), which are accelerated into space by fast-moving explosive events known as coronal mass ejections (CMEs). The fastest SEPs can reach Earth in less than a half hour after leaving the Sun.Unlike the CMEs themselves, SEPs do not cause the geomagnetic storms that can disrupt power grids and GPS systems on Earth. But they can harm astronauts and spacecraft, and they can block high latitude communications and increase radiation over the Earth’s poles, forcing airlines to reroute flights from shorter polar paths to longer lower latitude routes.The potential of SEPs to cause damage is associated with their energy and the amount of particles produced. CMEs that are fast and produce a particular type of radio emission tend to generate more dangerous SEPs. Therefore the ability to measure the early speed of a CME — and, later, to determine if there was an accompanying radio burst — can allow scientists to provide a warning that damaging space weather is on the way.A coronagraph can be used to measure the speed and acceleration of a CME, but only if it can capture multiple images closely spaced in time. Even then, those images would have to be provided quickly to space weather forecasters on Earth to be part of a useful warning system.Existing space-based coronagraphs, like those onboard the SOlar and Heliospheric Observatory (SOHO) and the Solar TErrestrial RElations Observatory (STEREO), take too few images and send those images back to Earth too infrequently to be used for this type of an operational warning system.But K-Cor, which has been operating at NCAR's Mauna Loa Solar Observatory (MLSO) since 2013, can deliver on both counts. The coronagraph can take a new image every 15 seconds, and those images are processed and available on the internet less than 15 minutes later. With the installation of a new, faster computer at MLSO — a project that is currently underway — the lag until the images are widely available could shrink to just a few minutes.Scientists at NASA Goddard Space Flight Center also are working to develop software that could automatically identify the formation of a CME in the data and flag it, a necessary step toward actually using K-Cor in an operational capacity.A successful test caseIn the new study, the researchers used an SEP event that occurred on Jan. 1, 2016, as a test case to see if K-Cor could be used to provide early warnings for these kinds of events. They found that K-Cor could have provided a warning 19 minutes earlier than any other instrument. But K-Cor has drawbacks, too."You can only see the Sun so many hours in a day from one ground-based site," Burkepile said. "On a good day, we get 10 hours of data, but you're at the mercy of the weather and the sky conditions."To address this, NASA or other agencies would need to deploy a half-dozen ground-based coronagraphs spaced longitudinally around the globe. Alternatively, agencies could deploy a single space-based coronagraph — if it could be engineered, like K-Cor, with the ability to measure white light, take frequent pictures, and communicate quickly with Earth.Either way, scientists would also need to prevent warnings that are false positives. While K-Cor can see the formation of a CME quite early, it takes many more minutes before other instruments can detect whether or not there will be an accompanying radio burst, which increases the likelihood that a damaging SEP event will occur."The first sign of a fast-moving CME event is really much more like a storm watch issued here on Earth," Burkepile said. "We have to wait until we have evidence of a radio burst to upgrade the watch to a storm warning."In the top row, an eruption from the Sun on Jan. 1, 2016, is captured in composite by the Solar Dynamics Observatory (in gold), the K-Coronagraph (in blue), and the Solar Helophysics Observatory (red). (Image courtesy of Joan Burkepile, NCAR.)  About the articleTitle: Solar energetic particle warnings from a coronagraphAuthors: O. C. St. Cyr, A. Posner, and J. T. BurkepileJournal: Space Weather, DOI: 10.1002/2016SW001545Writer/contact:Laura Snider, Senior Science Writer and Public Information Officer  

UCAR/NCAR statement on the passing of Matthew J. Parker

The National Center for Atmospheric Research (NCAR) and the University Corporation for Atmospheric Research (UCAR) join American Meteorological Society (AMS) colleagues and those in the broader meteorological community in mourning the passing of AMS President Matthew J. Parker, who died on March 15.This past January, Parker took over as AMS president during the society’s annual meeting in Seattle having been elected as president-elected in November 2015. He had spent much of his career, since 1989, at Savannah River National Laboratory in South Carolina. During that time, Parker rose through the ranks and was most recently senior fellow meteorologist in the Atmospheric Technologies Group.Matthew Parker (Photo courtesy of the American Meteorological Society.)“Matt was a true leader in the community who advocated for an analysis to show the value and return on investment in the weather enterprise,” said UCAR President Antonio J. Busalacchi. “Matt was a strong supporter of a more diverse and inclusive weather enterprise and while at the Department of Energy, worked to integrate all parts of the community, including the public, private, and academic sectors. This loss will be deeply felt.”NCAR Director James W. Hurrell expressed a similar sentiment, noting that Parker’s passing “is an enormous loss for the entire scientific community. Matt was a tremendous leader who was deeply committed to our field, and to AMS in particular. He will be sorely missed.”  William Mahoney, interim director of NCAR’s Research Applications Laboratory and Commissioner of AMS’s Commission on the Weather, Water, and Climate Enterprise, added: “Matt understood that creating collaboration among government, private, and academic sectors could be a powerful and effective strategy for advancing our scientific and operational capabilities. We will miss Matt’s leadership but the Commission will continue to work on implementing his vision.”See AMS’s statement here.

New estimate of ocean heat finds more warming

March 10, 2017 | The oceans may be storing 13 percent more heat than previously estimated, according to a new study co-authored by scientists at the National Center for Atmospheric Research (NCAR).The finding, published in the journal Science Advances, is based on a new analysis of how ocean temperatures have changed since 1960. The research team, led by Lijing Cheng of the Chinese Academy of Sciences, compared their results to estimates published in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change in 2013."In other words, the planet is warming quite a lot more than we thought," said NCAR scientist Kevin Trenberth, a study co-author.The vast majority of excess heat trapped on Earth by greenhouse gas emissions — about 90 percent — is stored in the oceans, but measuring how the heat content of the oceans has changed over time has been a challenge due to sparse observations.The deployment of an Argo float off a research vessel. Data collected from Argo floats were used to validate a new estimate of ocean heat content. (Image courtesy of the Australian Commonwealth Scientific and Industrial Research Organization.)Historically, the temperature of ocean waters was measured by a variety of ships, but this limited observations to areas where ships traveled. In more recent decades, measurements of ocean heat have increased, thanks to new observational techniques. In 2000, scientists began deploying a network of thousands of floats called Argo to profile conditions in the top layer of the ocean extending down 2,000 meters (6,562 feet). Argo achieved near global coverage in 2005, though some remote regions are still not sampled.To fill the large gaps in the historical ocean temperature record, the research team used a combination of statistical techniques and model output to determine how useful a single observation can be for inferring information about the surrounding area, as well as how the temperatures in different parts of the world's oceans relate to one another. They found that, in most regions, a single ocean observation could provide valuable information about conditions as far as 2,000 kilometers (1,243 miles) away.To check if they were correct, they used Argo observations. At first, they chose data from only a small number of floats in the network to mimic the scarcity of observations that would have been available in the mid-20th century. Then they used their new technique to create an entire ocean temperature map based on those few observations. When they checked their map against the full complement of Argo observations, they found that their reconstruction tracked closely with reality. "The results were remarkable," Trenberth said. "They give us much more confidence about what the ocean heat content was, stretching back to the late 1950s."The results allowed the team to estimate the total warming between 1960 and 2005 to be 337 zettajoules (a measure of energy). They also found that changes were small until 1980, when the amount of heat stored in the oceans began to steadily increase. Since 1990, significant amounts of heat have begun to seep deeper into the ocean layers. NCAR scientist and co-author John Fasullo said the study also highlights the impact of improved observations and models, which are giving scientists important insights into what the world once looked like."Science not only looks toward the future, but is also continually trying to make sense of the past," he said. "This work is an example of how advances in technology have enabled an improved understanding of past changes in the ocean, where variability has always been a bit of an enigma due to its vastness and depth. The insights associated with this work change not only our understanding of past climate but also how future changes might unfold."The other co-authors are Tim Boyer, of the National Oceanic and Atmospheric Administration; John Abraham, of the University of St. Thomas; and Jiang Zhu, of the Chinese Academy of Sciences.About the articleTitle: Improved estimates of ocean heat content from 1960 to 2015Authors: Lijing Cheng, Kevin Trenberth, John Fasullo, Tim Boyer, John Abraham, and Jiang ZhuJournal: Science Advances, DOI: 10.1126/sciadv.1601545Writer/contactLaura Snider, Senior Science Writer and Public Information Officer FundersChinese Academy of SciencesNational Science Foundation of ChinaU.S. Department of EnergyNational Science FoundationNASA CollaboratorsChinese Academy of SciencesNational Oceanic and Atmospheric AdministrationUniversity of St. Thomas

Opening doors to a career in geoscience

March 8, 2017 | Michael Bell, recently honored as one of America's outstanding early-career scientists, took an unconventional path to becoming a top tropical cyclone researcher.Bell said he always had an interest in meteorology but the University of Florida, where he first attended, didn't have that major. "I started as a physics major, but I realized that high energy particle physics wasn't for me." So, because he had enjoyed his comparative religion classes, he wound up as a religion major.But since he already had taken many math and physics courses, it was relatively straightforward to go back to school and pursue a second bachelor's in mathematics and meteorology at Metropolitan State College (now Metropolitan State University) in Denver. There he had a professor, Anthony Rockwood, who had worked at the National Center for Atmospheric Research and encouraged Bell to apply for a student assistantship.Michael Montgomery, Michael Bell, and Wen-Chau Lee (left to right) during the THORPEX Pacific Asian Regional Campaign in Guam in 2008. Lee was Bell's mentor at NCAR and Montgomery, of the Naval Postgraduate School, was Bell's Ph.D. adviser. (Photo courtesy Wen-Chau Lee, NCAR.)The cliché is that the rest is history, and it fits in this case. Bell was so successful as a student assistant that he would spend another decade at NCAR before leaving for academia. In December 2016, President Obama honored Bell as one of America's outstanding early-career scientists. The Office of Naval Research nominated Bell for the award in recognition of his hurricane and typhoon research, much of which was done for the Navy."This is a career highlight for me, " Bell, wrote in an email to his mentor Wen-Chau Lee, an NCAR senior scientist, shortly after being notified of the honor. "I owe you a debt of gratitude for all of the opportunities you have provided me over the years.""NCAR taught me to think critically about data quality and the assumptions that go into data," Bell, now an associate professor at Colorado State University, said in a recent interview. "The field projects (which included flying close to hurricanes) taught me the importance of careful planning and execution, so when the weather you want to study occurs, you're ready to take advantage of it."Bell's enthusiasm and desire to learn impressed the NCAR hiring team, Lee recalled. "He said, 'I want this, I think I can do it.'""I have to invest a lot of time to train a student assistant," Lee said, "so I wasn't looking for a candidate with a ton of programming experiences who would stay a year and leave. I was looking for someone who could assist me over the relatively long term, and I had a feeling that Michael could do it."During his stint at NCAR, Bell was part of at least a half-dozen field campaigns, including RAINEX (Hurricane Rainband and Intensity Change Experiment) in 2005, and T-PARC (THORPEX Pacific Asian Regional Campaign) in 2008. He served as a principal investigator for PREDICT (Pre-Depression Investigation of Cloud Systems in the Tropics), which examined hurricane formation.Lee, Bell, and Paul Harasti of the Naval Research Laboratory also co-developed a tool called VORTRAC (Vortex Objective Radar Tracking and Circulation) that enabled hurricane specialists for the first time to continually monitor central pressure as a fast-changing storm nears land.A rich tradition of mentoringThe National Center for Atmospheric Research and the University Corporation for Atmospheric Research have a tradition of helping develop the next generation of scientists.In fiscal 2016 alone, there were more than 400 examples of NCAR and UCAR scientists and engineers working with student-scientists on activities such as mentoring, advising, thesis review, and teaching."There's no shortage of channels available to get great students from prestigious organizations, but the kind of informal programs like student assistantships show how NCAR opens the door for people who otherwise wouldn't get the opportunity," said Senior Scientist Wen-Chau Lee of NCAR's Earth Observing Laboratory.There are also several formal examples, including SOARS (Significant Opportunities in Atmospheric Research & Science), a UCAR program begun more than two decades ago to broaden participation in atmospheric sciences. In fiscal year 2016, about 65 student protégés either participated in SOARS internships or were supported through webinars and career advising.With mentoring opportunities from undergraduate internships through postdoctoral fellowships, NCAR|UCAR student-scientists have gone on to successful careers in government labs, academia, and the private sector, and many have taken on leadership roles. In the SOARS program alone, more than 100 students have earned a master's degree in science or engineering to date, and three dozen have gone on to get their Ph.D.s.While working at NCAR, Bell earned a master's degree in atmospheric science from Colorado State University and a Ph.D. in meteorology from the Naval Postgraduate School. The Education Assistance program of the University Corporation for Atmospheric Research paid tuition for his master's degree. (UCAR manages NCAR with sponsorship by the National Science Foundation.)"Michael always took advantage of the opportunities provided to him," Lee said. "There's an old saying of Confucius that to be a mentor or teacher is like being a big bell. The harder a student hits the bell, the greater the sound. If a student is eager to learn, I will put forward more from my end to challenge them."Graduate students at the University of Hawaii received radar training from Wen-Chau Lee (NCAR, far left) and Michael Bell (University of Hawaii, back row, second from left) in 2013 during an educational deployment of a Doppler on Wheels radar system that was sponsored by the National Science Foundation. Lee's participation was supported by the UCAR UVisit program. (Photo courtesy Wen-Chau Lee, NCAR.)Recalling Bell's early years, NCAR scientist Bob Rilling said: "Michael had a real curiosity and an analytical approach to problems. You could see his wheels turning. He wanted to make things work."The relationship between NCAR and Bell continued long after he moved on in his career.For example, in 2013, Bell invited Lee to the University of Hawaii as part of a UVisit program administered by UCAR. Lee gave lectures to Bell's radar class and helped Bell train graduate students during a Doppler on Wheels educational deployment as part of the Hawaiian Educational Radar Opportunity, a program sponsored by the National Science Foundation.Lee in turn asked Bell to become the principal investigator on a new project called the Lidar Radar Open Software Environment, or LROSE.LROSE aims to develop a unified open source software tool to handle the copious quantities of atmospheric data produced by radars and lidars. The collaboration won a competitive grant from the National Science Foundation Software Infrastructure for Sustained Innovation program, and a community workshop is planned for April at NCAR.Summing up NCAR's role in his professional life, Bell said, "I worked with a lot of good people, like Wen-Chau, and they really helped launch me into my current career."Writer/ContactJeff Smith, Science Writer and Public Information Officer  

From GOES-16 to the world

March 6, 2017 | As atmospheric scientists around the world look forward to seeing extraordinarily detailed images from the new GOES-16 satellite, the University Corporation for Atmospheric Research (UCAR) and National Center for Atmospheric Research (NCAR) are preparing for central roles in disseminating the satellite's data.The first of a series of next-generation National Oceanic and Atmospheric Administration (NOAA) satellites, GOES-16 was launched in November and is expected to become fully operational late this year. It will immediately improve weather forecasts with its rapid, high-resolution views of hurricanes, thunderstorms, and other severe events, as well as provide a breakthrough lightning mapping system and more detailed monitoring of geomagnetic disturbances caused by the Sun."Scientists are rightfully excited because this is a revolutionary system," said Mohan Ramamurthy, director of UCAR's Unidata Program. "It's going to truly transform weather forecasting and research."GOES-16 captured this view of the mid-Atlantic and New England states on Jan. 15. (Image by National Oceanic and Atmospheric Administration.) Data from GOES-16 will be transmitted to a new downlink facility at the NCAR Mesa Lab. Unidata, which provides data, software tools, and support to enhance Earth system science education and research, will then make that data widely available.  As the only open-access and free source of GOES data in real time, Unidata's services have become indispensable to scientists as well as to operational forecasters in regions that lack their own downlink facilities, such as parts of Latin America.In addition, NCAR's Earth Observing Laboratory (EOL) will produce customized data products from GOES-16 to support field campaigns. EOL currently uses observations from GOES satellites and other sources to help scientists make critical decisions as they're taking measurements in the field.More data than everFor years, NCAR and UCAR have provided real-time data from a series of NOAA satellites known as GOES (Geostationary Operational Environmental Satellite). These satellites, which provide views of the Americas and adjoining ocean regions, are part of a global network of satellites whose observations are shared by forecasters and researchers worldwide.But the advantages of GOES-16 also create new challenges. The satellite has three times as many spectral channels as its predecessors, each with four times more resolution. It can scan the entire Western Hemisphere every 15 minutes and simultaneously generate images of severe weather every 30-60 seconds. All this data will amount to about 1 terabyte per day, more than 100 times the amount of data produced by an existing GOES satellite. And even more data can be expected when NOAA launches additional advanced GOES satellites in coming years.Thanks to a NOAA grant, UCAR and NCAR have installed a direct broadcast receiving station to receive the data, as well as the computers and electronics needed to process and transmit it. In addition to Unidata and EOL, NCAR's Research Applications Laboratory helps operate the downlink facilities for existing GOES satellites and relies on satellite data for the development of specialized forecasting products.The volume of information means that Unidata will continue to move toward making data available in the cloud. It will store GOES-16 data for about 10 days and is in discussions with Amazon over long-term storage options.EOL will customize GOES-16 observations for worldwide field projects, which advance understanding of Earth system science, including weather, climate, and air quality. Such projects deploy teams of scientists with aircraft, ships, ground-based instruments, and other tools. They rely on detailed forecasts and real-time updates about evolving atmospheric conditions."The data from GOES 16 will provide invaluable information for flight planning and decision making during field projects," said EOL director Vanda Grubišić. "This will enable scientists to gather additional observations, further advancing our understanding of the atmosphere and related aspects of the Earth system."EOL will also include the GOES data in their field catalog, along with measurements from field campaigns and other observations. This catalog is widely used by scientists when analyzing results from past campaigns or planning new ones.Other scientists say they are looking forward to the new capabilities that GOES-16 offers."The observations collected by the Geostationary Lightning Mapper on GOES-16 have the potential to help advance our understanding of hurricanes and their intensity changes," said Kristen Corboseiero, a professor in the Department of Atmospheric and Environmental Sciences at the University of Albany-SUNY. "Being able to access this data through Unidata will streamline and expedite our research."In Costa Rica, agencies are planning to use the GOES-16 data from Unidata for weather forecasting and research. In addition, the data will help with monitoring water levels for hydropower to avoid possible power cuts during the dry season, as well as for observing volcanic ash that can affect aviation and farming near San Jose."Several institutions will be using the new GOES-16 data in ways that will help safeguard society from potential natural disasters as well as avoiding energy shortages," said Marcial Garbanzo Salas, an atmospheric sciences professor at the Universidad de Costa Rica (University of Costa Rica). "This is extremely important to us, and we're very pleased that Unidata will be making it available."Writer/contact:David Hosansky, Media Relations ManagerFunder:National Oceanic and Atmospheric Administration

Slower snowmelt in a warming world

BOULDER, Colo. — As the world warms, mountain snowpack will not only melt earlier, it will also melt more slowly, according to a new study by scientists at the National Center for Atmospheric Research (NCAR).The counterintuitive finding, published today in the journal Nature Climate Change, could have widespread implications for water supplies, ecosystem health, and flood risk."When snowmelt shifts earlier in the year, the snow is no longer melting under the high sun angles of late spring and early summer," said NCAR postdoctoral researcher Keith Musselman, lead author of the paper. "The Sun just isn't providing enough energy at that time of year to drive high snowmelt rates."Snowpack in the Colorado Rockies as seen from the NSF/NCAR C-130 research aircraft. (©UCAR. Photo by Carlye Calvin. This image is freely available for media & nonprofit use.)The study was funded by the National Science Foundation, NCAR's sponsor.The findings could explain recent research that suggests the average streamflow in watersheds encompassing snowy mountains may decline as the climate warms — even if the total amount of precipitation in the watershed remains unchanged. That's because the snowmelt rate can directly affect streamflow. When snowpack melts more slowly, the resulting water lingers in the soil, giving plants more opportunity to take up the moisture. Water absorbed by plants is water that doesn't make it into the stream, potentially reducing flows.Musselman first became interested in how snowmelt rates might change in the future when he was doing research in the Sierra Nevada. He noticed that shallower, lower-elevation snowpack melted earlier and more slowly than thicker, higher-elevation snowpack. The snow at cooler, higher elevations tended to stick around until early summer — when the Sun was relatively high in the sky and the days had grown longer — so when it finally started to melt, the melt was rapid.Musselman wondered if the same phenomenon would unfold in a future climate, when warmer temperatures are expected to transform higher-elevation snowpack into something that looks much more like today's lower-elevation snowpack. If so, the result would be more snow melting slowly and less snow melting quickly. To investigate the question, Musselman first confirmed what he'd noticed in the Sierra by analyzing a decade's worth of snowpack observations from 979 stations in the United States and Canada. He and his co-authors — NCAR scientists Martyn Clark, Changhai Liu, Kyoko Ikeda, and Roy Rasmussen — then simulated snowpack over the same decade using the NCAR-based Weather Research and Forecasting (WRF) model.Once they determined that the output from WRF tracked with the observations, they used simulations from the model to investigate how snowmelt rates might change in North America around the end of the century if climate change continues unabated."We found a decrease in the total volume of meltwater — which makes sense given that we expect there to be less snow overall in the future," Musselman said. "But even with this decrease, we found an increase in the amount of water produced at low melt rates and, on the flip side, a decrease in the amount of water produced at high melt rates."While the study did not investigate the range of implications that could come from the findings, Musselman said the impacts could be far-reaching. For example, a reduction in high melt rates could mean fewer spring floods, which could lower the risk of infrastructure damage but also negatively affect riparian ecosystems. Changes in the timing and amount of snowmelt runoff could also cause warmer stream temperatures, which would affect trout and other fish species, and the expected decrease in streamflow could cause shortages in urban water supplies."We hope this study motivates scientists from many other disciplines to dig into our research so we can better understand the vast implications of this projected shift in hydrologic patterns," Musselman said.About the articleTitle: Slower snowmelt in a warmer worldAuthors: Keith N. Musselman, Martyn P. Clark, Changhai Liu, Kyoko Ikeda, and Roy RasmussenJournal: Nature Climate Change, DOI: 10.1038/nclimate3225WriterLaura Snider, Senior Science Writer and Public Information OfficerFunderNational Science Foundation

High-resolution regional modeling (no supercomputer needed)

Annual precipitation over Colorado as modeled by the low-resolution, global Community Earth System Model (top) compared to the high-resolution, regional Weather Research and Forecasting model (below). (Images courtesy Ethan Gutmann, NCAR.) February 13, 2017 | In global climate models, the hulking, jagged Rocky Mountains are often reduced to smooth, blurry bumps. It's a practical reality that these models, which depict the entire planet, typically need to be run at a relatively low resolution due to constraints on supercomputing resources. But the result, a virtual morphing of peaks into hills, affects the ability of climate models to accurately project how precipitation in mountainous regions may change in the future — information that is critically important to water managers.To address the problem, hydrologists have typically relied on two methods to "downscale" climate model data to make them more useful. The first, which uses statistical techniques, is fast and doesn't require a supercomputer, but it makes many unrealistic assumptions. The second, which uses a high-resolution weather model like the Weather Research and Forecasting model (WRF), is much more realistic but requires vast amounts of computing resources.Now hydrologists at the National Center for Atmospheric Research (NCAR) are developing an in-between option: The Intermediate Complexity Atmospheric Research Model (ICAR) gives researchers increased accuracy using only a tiny fraction of the computing resources."ICAR is about 80 percent as accurate as WRF in the mountainous areas we studied," said NCAR scientist Ethan Gutmann, who is leading the development of ICAR. "But it only uses 1 percent of the computing resources. I can run it on my laptop."Drier mountains, wetter plainsHow much precipitation falls in the mountains — and when — is vitally important for communities in the American West and elsewhere that rely on snowpack to act as a frozen reservoir of sorts. Water managers in these areas are extremely interested in how a changing climate might affect snowfall and temperature, and therefore snowpack, in these regions.But since global climate models with low resolution are not able to accurately represent the complex topography of mountain ranges, they are unsuited for answering these questions.For example, as air flows into Colorado from the west, the Rocky Mountains force that air to rise, cooling it and causing moisture to condense and fall to the ground as snow or rain. Once these air masses clear the mountains, they are drier than they otherwise would have been, so there is less moisture available to fall across Colorado's eastern plains.Low-resolution climate models are not able to capture this mechanism — the lifting of air over the mountains — and so in Colorado, for example, they often simulate mountains that are drier than they should be and plains that are wetter. For a regional water manger, these small shifts could mean the difference between full reservoirs and water shortages."Climate models are useful for predicting large-scale circulation patterns around the whole globe, not for predicting precipitation in the mountains or in your backyard," Gutmann said.Precipitation in millimeters over Colorado between Oct. 1 and May 1 as simulated by the Weather Research and Forecasting model (WRF), the Intermediate Complexity Atmospheric Research model (ICAR), and the observation-based Parameter-Elevation Regressions on Independent Slopes Model. (Images courtesy Ethan Gutmann.)A modeling middle groundA simple statistical fix for these known problems may include adjusting precipitation data to dry out areas known to be too wet and moisten areas known to be too dry. The problem is that these statistical downscaling adjustments don't capture the physical mechanisms responsible for the errors. This means that any impact of a warming climate on the mechanisms themselves would not be accurately portrayed using a statistical technique.That's why using a model like WRF to dynamically downscale the climate data produces more reliable results — the model is actually solving the complex mathematical equations that describe the dynamics of the atmosphere. But all those incredibly detailed calculations also take an incredible amount of computing.A few years ago, Gutmann began to wonder if there was a middle ground. Could he make a model that would solve the equations for just a small portion of the atmospheric dynamics that are important to hydrologists — in this case, the lifting of air masses over the mountains — but not others that are less relevant?"I was studying statistical downscaling techniques, which are widely used in hydrology, and I thought, 'We should be able to do better than this,'" he said. "'We know what happens when you lift air up over a mountain range, so why don’t we just do that?'"Gutmann wrote the original code for the model that would become ICAR in just a few months, but he spent the next four years refining it, a process that's still ongoing.100 times as fastLast year, Gutmann and his colleagues — Martyn Clark and Roy Rasmussen, also of NCAR; Idar Barstad, of Uni Research Computing in Bergen, Norway; and Jeffrey Arnold, of the U.S. Army Corps of Engineers — published a study comparing simulations of Colorado created by ICAR and WRF against observations.The authors found that ICAR and WRF results were generally in good agreement with the observations, especially in the mountains and during the winter. One of ICAR's weaknesses, however, is in simulating storms that build over the plains in the summertime. Unlike WRF, which actually allows storms to form and build in the model, ICAR estimates the number of storms likely to form, given the atmospheric conditions, a method called parameterization.Even so, ICAR, which is freely available to anyone who wants to use it, is already being run by teams in Norway, Austria, France, Chile, and New Zealand."ICAR is not perfect; it's a simple model," Gutmann said. "But in the mountains, ICAR can get you 80 to 90 percent of the way there at 100 times the speed of WRF. And if you choose to simplify some of the physics in ICAR, you can get it close to 1,000 times faster."About the articleTitle: The Intermediate Complexity Atmospheric Research Model (ICAR)Authors: Ethan Gutmann, Idar Barstad, Martyn Clark, Jeffrey Arnold, and Roy RasmussenJournal: Journal of Hydrometeorology, DOI: 10.1175/JHM-D-15-0155.1Funders:U.S. Army Corps of EngineersU.S. Bureau of ReclamationCollaborators:Uni Research Computing in NorwayU.S. Army Corps of EngineersWriter/contact: Laura Snider, Senior Science Writer

Scientists take to the skies to test cloud seeding

February 7, 2017 | Does cloud seeding successfully increase snowfall? This winter, scientists with the National Center for Atmospheric Research (NCAR) are taking part in a field project in Idaho that will help answer the question.The project, called SNOWIE (Seeded and Natural Orographic Wintertime Clouds — the Idaho Experiment), is taking place from Jan. 7 to March 17 in the Payette Basin region north of Boise. A public-private partnership, SNOWIE is led by scientists at the University of Wyoming and other universities in collaboration with NCAR, with funding from the National Science Foundation (which is NCAR's sponsor) and the Idaho Power Company.The research team is using airborne and ground-based radars, high-resolution snow gauges, and computer modeling to gain insights into what happens after clouds are seeded with silver iodide. Snow from winter storms develops when ice crystals form on dust and other particles known as "ice nuclei." In cloud seeding, silver iodide is used to make artificial nuclei to encourage snowflakes to form.Silver iodide is released during the SNOWIE field project in such a way that it disperses downwind to the east, with its highest concentrations forming a zigzag pattern (shown in red). This allows scientists to fly a research aircraft from west to east through both seeded and unseeded regions and compare differences in ice crystal formation. (Image by Lulin Xue, ©UCAR. This image is freely available for media & nonprofit use.)NCAR scientists are focusing much of their work on observations taken by a University of Wyoming King Air plane that is flying though plumes of silver iodide released by a seeding aircraft. The silver iodide disperses downwind in a zigzag pattern, enabling the King Air to intercept it multiple times. The scientists will compare the formation of ice crystals in regions of clouds that are seeded with those that are not.The results can also be used to improve the NCAR-based Weather Research and Forecasting model (WRF), especially its simulation of cloud microphysics related to cloud seeding.Although scientists think that cloud seeding and other types of weather modification can increase precipitation in certain circumstances, the effects are difficult to quantify."NCAR's role in these weather modification experiments is to provide an unbiased viewpoint," said NCAR scientist Sarah Tessendorf, a principal investigator on SNOWIE. "The project uses observations and computer models to determine what is happening during a cloud seeding program and whether it is effective as a water augmentation tool."For more about the project, see the NSF news release.Writer/contactDavid Hosansky, Manager of Media RelationsFundersNational Science FoundationIdaho Power CompanyPartnersUniversity of WyomingIdaho Power CompanyUniversity of Colorado BoulderUniversity of Illinois at Urbana-ChampaignBoise State UniversityCenter for Severe Weather ResearchWeather Modification, Inc.

New apps set atmospheric data spinning in 3D

Feburary 6, 2017 | Students of microbiology can grow bacteria in petri dishes to better understand their subject. Paleontology students have fossils, and chemistry students have beakers bubbling with reactions. But students of the atmospheric and related sciences are often left with something much less tangible: data, and lots of it.The Meteo AR app uses augmented-reality techniquest to make atmospheric science data more accessible to the public. (©UCAR. This animation is freely available for media & nonprofit use.)Datasets in the atmospheric sciences cover everything from observations made by weather balloons to satellite measurements of cloud cover to output from climate model runs.Now the National Center for Atmospheric Research (NCAR) is helping make those data less abstract and more concrete  — a little closer to a rock sample and a little further from a computer file. The result is two apps: one using virtual-reality and one using augmented-reality techniques to create 3D visualizations of datasets on a globe that students can move around and view from different perspectives. Meteo VR (Virtual Reality) and Meteo AR (Augmented Reality) are available for use on iPhone, iPad, and Android devices. They were developed by NCAR's Computational and Information Systems Lab (CISL)."The goal is to make our data more accessible to the public, especially to students," said Tim Scheitlin, a senior software engineer at CISL's Visualization Lab. "We think it's a fun way to start a dialogue about atmospheric science. If people can get excited about using the app, then maybe they'll start asking questions that will lead to a deeper understanding."The 'wow' factor and beyondThe Meteo AR app takes advantage of the camera on a personal device. When the camera's pointed at an image from a visualization — of sea surface temperature anomalies during an El Niño, or of the inner workings of a hurricane, for example — the visualization pops up onto a 3D globe that can be spun around with a finger.The Meteo VR app requires a virtual reality headset, such as Google Cardboard, and allows the user to "fly around" the globe to look at the projected dataset from any angle.Development of the two apps was led by Nihanth Cherukuru, a doctoral student at Arizona State University. He came to NCAR last summer as part of CISL's Summer Internships in Parallel Computational Science (SIParCS) program, which strives "to make a long-term, positive impact on the quality and diversity of the workforce needed to use and operate 21st century supercomputers."Cherukuru said one of the challenges of the project was to wrestle the vast amounts of data into a format that wouldn’t crash a handheld device. "Mobile phones are tiny devices and the atmospheric data can be really huge," Cherukuru said. "We needed to take that data and trim it down. We created a single image for each timestamp and then we made animations to reduce the computational burden on the phones."While Cherukuru has returned to Arizona State after his SIParCS internship, he is still working with the Visualization Lab. The goal is to expand the apps' capabilities, perhaps, for example, by having users click on parts of the data to get more information."There's kind of a 'wow' factor you get when you first use the app," Scheitlin said. "Our goal is to get past that and make it as educational as we can." Download the appsMeteo AR:For iPhone or iPadFor AndroidMeteo VR:For iPhone or iPadFor Android Writer/contact:Laura Snider, senior science writer

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