Capturing a detailed portrait of wind

April 28, 2017 | For two autumns in the early 1980s, researchers covered an isolated, gently sloping hill in Scotland with dozens of scientific instruments to measure the behavior of wind as it blew up and over from the nearby coast. More than three decades later, the resulting data set gathered on Askervein hill is still the benchmark for validating how well a computer model can simulate winds flowing over complex terrain.An image of the hill at Askervein. (Image courtesy of York University.)But that's about to change.The National Center for Atmospheric Research (NCAR) is partnering with colleagues in Europe and the United States on a field project in Portugal, called Perdigão, that will measure wind at an unprecedented resolution, both in time and space, as it moves through a more topographically diverse study area.The experiment aims to help scientists improve their understanding of the basic physics of wind in the boundary layer (the lowest few hundred feet of the atmosphere). The completed data set will also serve as a new, more detailed, and more complex benchmark for testing the accuracy of the next generation of wind models.Having accurate models of wind behavior in the boundary layer, where most weather occurs, is critical for a wide range of applications, from harvesting wind energy to predicting the spread of air pollution to piloting drones.'No easy feat'When scientists selected the Perdigão study area in central Portugal, they were looking for a place more complex than the single hill at Askervein but still relatively simple and easy to model.Perdigão has two nearly parallel ridgelines that stand just a couple of kilometers apart, and the wind typically hits these ridges at a perpendicular angle, either from the southwest or the northeast. Unlike the Askervein hill, which was covered largely in heather and small shrubs, the landscape at Perdigão includes both forested and agricultural lands. Such differences in terrain and land cover can have important influences on local winds.For the project, which begins its six-week "intensive operations period" on May 1, NCAR's Earth Observing Lab was tasked with outfitting 47 observational towers with instruments that will collect data on wind speed and direction, as well as temperature and humidity, from a variety of heights. The NCAR team is also in charge of networking all the instruments being used for the field campaign so they can talk to each other and to the researchers."This is the largest ground-based project we have ever taken on," said Alison Rockwell, who is managing the project for NCAR. "Networking that many towers with that many instruments — it's no easy feat."The Perdigão study area, with its nearly parallel ridges, as seen using Google Earth. (©UCAR. Courtesy NCAR Earth Observing Laboratory. This image is freely available for media & nonprofit use.) A unique look at the wind's mysteriesThe measurements taken by the instruments on the 47 towers outfitted by NCAR, along with those from five additional towers provided by project partners, will be supplemented by observations from a variety of other balloon-borne and ground-based instruments. Those include lidars, which can remotely measure the basic structure of the wind field using laser beams."One of the totally unique aspects of this experiment is the use of lidars to measure the main wind field," said NCAR scientist Steve Oncley, a contributing investigator on the project. "It frees up the instruments on the towers to measure the fine-scale turbulence close to the ground."This ability to measure the wind at multiple scales simultaneously is another reason that data gathered during Perdigão is expected to be a vast improvement over the 1980s data set. While a similar number of towers were deployed at the Askervein hill, the instruments primarily measured wind at only one height, leaving much of the structure of fine-scale turbulence occurring close to ground a mystery.One of the questions that Oncley hopes the experiment will answer in particular — which the 1980s data could not — is how wind behaves as it blows over the crest of the ridge: "When you have a strong wind, does it actually blow through the trees, down to the soil? Or does it just graze the tops of the trees as it flows over?"The answer matters for understanding how much momentum is extracted from the wind, as well as how much heat and carbon dioxide are transferred between wind and landscape.The Perdigão project is part of a larger effort to publish a digital New European Wind Atlas, supported by a European Union funding instrument called ERANET+. The Europeans are particularly interested in the detailed wind velocity data for use in wind energy development.U.S. principal investigators are Joe Fernando (University of Notre Dame), Julie Lundquist (University of Colorado, Boulder), Petra Klein (University of Oklahoma), Rebecca Barthelmie (Cornell University), Sara Pryor (Cornell University), Tina Katopodes Chow (University of California, Berkeley), Chris Hocust (U.S. Army Research Laboratory), and Laura Leo (University of Notre Dame).European Principal Investigators are Jakob Mann (Technical University of Denmark) and José Palma (University of Porto, Portugal).Data from a long-range wind scanner at the Perdigão site  Writer/contact:Laura Snider, Senior Science Writer and Public Information Officer

EOL Seminar: Marine Ice Nucleating Particles: Implications for High Latitude Aerosol-Cloud Interactions

Marine Ice Nucleating Particles: Implications for High Latitude Aerosol-Cloud Interactions

Christina S. McCluskey
Department of Atmospheric Science
Colorado State University

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

EOL Seminar: Climate Engineering: Benefits, Side-Effects, Risks, and Opportunities

Climate Engineering: Benefits, Side-Effects, Risks, and Opportunities

Dr. Simone Tilmes

Atmospheric Chemistry Observations & Division, NCAR


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