A guide to 2005
Most of the research performed under the auspices of the Space Science and Engineering Center, chiefly in its Cooperative Institute for Meteorological Satellite Studies, focuses on different aspects of Earth’s atmosphere. Over the past year, SSEC affiliates made several advances that positively affect the general public and open doors for further development.
Weather in the palm of your hand—Russ Dengel created the PDA Animated Weather online service, or PAW, that permits PDA users to obtain weather products on demand. What started as a tool for Dengel and a few co-workers now benefits a diverse community from long-haul truck drivers to firefighters in Puerto Rico to commuters trying to get to work safely on a snowy morning. The free service allows PDA users to access real-time radar and satellite weather images and forecasts whenever and wherever. The PAW received much attention in 2005 and continues to evolve to accommodate user requests.
WRF improves simulations—Using data from the Atlantic THORPEX Regional Campaign, the Weather Research Forecast (WRF) model produced a realistic simulation of an extratropical cyclone that occurred on December 5, 2003. The simulation is of a very high resolution—1070x1070 grid points with 50 vertical levels and two km horizontal resolution. The WRF model also produced a high resolution full-disk simulation. This simulation is 1570x1830 grid points with 50 vertical levels and eight km horizontal resolution. Running this simulation took approximately 60% of SSEC’s supercomputer’s memory resources. Obtained last year, the supercomputer has 24 processors and 192 GB of RAM. Next up for the WRF model is a 1200x1200 simulation with one km horizontal resolution.
Working on IDEA—Scott Lindstrom of SSEC’s Infusing satellite Data into Environmental Applications (IDEA) team adapted Tom Whittaker’s AniS Java animation technique to generate hourly air quality displays using MODIS data. The IDEA team made strong adaptations to a Langley Research Center process to create air quality forecasts with MODIS data. In 2005, the team also began work with NOAA to incorporate MODIS data in a new national air quality forecasting system. Besides team leader Tony Wimmers, the team is made up of Lindstrom, Scott Bachmeier, Kathy Strabala and Bill Bellon.
Improving GOES data —Besides simulating satellite instruments in the planning stages, CIMSS researchers continually work to make data products from current satellites better. In 2005, Jun Li and his team improved water vapor retrievals from the current GOES Sounder.
Working together toward better data—CIMSS researchers and the Advanced Satellite Products Branch, the NOAA group supporting SSEC’s CIMSS, simulate data that scientists hope will be produced by satellites that are currently under development. In the process, they use all resources available around the world. Scientists in other countries also use satellite data, and are eager to collaborate on future instruments and data products.
The EUropean organization for the exploitation of METeorological SATellites (EUMETSAT) is collaborating on definition of the GOES-R Sounder, planned for the next decade. China’s National Satellite Meteorological Center is working more closely with SSEC’s CIMSS to develop data applications for the GOES-R Imager using data from a current European instrument.
Brightest cloud feature—Lawrence Sromovsky (SSEC) and Patrick Fry (SSEC) discovered the brightest cloud feature ever observed on Uranus. It was detected in images obtained with the NIRC2 and adaptive optics of the Keck II telescope on August 14 and 15, 2005, but is large enough and bright enough to be observed without adaptive optics.
Assimilation into NCEP’s Global Forecasting System—Jim Jung and Tom Zapotocny participated in the successful assimilation of AIRS radiances and MODIS winds data into the National Centers for Environmental Prediction’s Global Forecasting System. Using the MODIS winds data, Jung and Zapotocny helped to resolve some logistical problems with data delivery and incorporate quality control procedures into the GFS. The data was tested over two seasons. After testing the AIRS dataset generated by NASA and NOAA and modifying selection criteria, approximately five percent more AIRS radiance data pass the GFS quality control checks.
Polar winds from MODIS data—CIMSS researchers are now generating winds with MODIS data received by the National Science Foundation’s direct broadcast system in McMurdo, Antarctica. All the processing is done in McMurdo, and only the wind data and plots are sent back to CIMSS. Our goals for this system are to reduce the time it takes to generate wind information so more can be assimilated by numerical weather prediction systems, and to provide forecasters in McMurdo with real-time products. We continue to generate winds for both poles using other data sources.
Quantifying cloud liquid water—Dave Turner is using SSEC’s Atmospheric Emitted Radiance Interferometer (AERI) to determine the cloud liquid water path (LWP), known to meteorologists as the vertical integral of cloud liquid in a column of atmosphere. LWP is a critical variable needed to understand clouds and their role in the Earth-Atmosphere system. Researchers typically use two-channel microwave radiometers to measure liquid water, but these instruments are less accurate when the amount of liquid water is low.
AERIs at the Dept. of Energy’s Atmospheric Radiation Measurement (ARM) sites are located near microwave radiometers (MWR) and Turner is using them to characterize, and hopefully improve, the LWP retrievals from the MWRs. By comparing retrievals from both instruments, we can more fully understand both the retrieval methods and the MWR absorption models used to invert the observed brightness temperatures into LWP and other measurements.
Clouds on Uranus—Larry Sromovsky and Pat Fry’s research on planetary atmospheres led to the development of a new model of methane absorption at low temperatures, giving way to a new interpretation of the cloud structure on Uranus. The results appeared in an edition of Icarus in early 2006 with the title “Near-IR methane absorption in outer planet atmospheres: Improved models of temperature dependence and implications for Uranus cloud structure.” The new model will be applied to Keck observations of Uranus and Neptune, and is also relevant to analysis of radiation transfer on Jupiter, Saturn, and Titan.
Uranus Dynamics—New ground-based observations with the Keck telescope made possible new measurements of cloud motions on Uranus. Larry Sromovsky and Pat Fry found that the zonal circulation on Uranus is asymmetric about the equator and variable; they also discovered an unusually long-lived (possibly two decades old) cloud feature in the southern hemisphere that slowly oscillates in latitude and longitude with a very long period that is roughly consistent with that of a Rossby wave. It also oscillates with a much more rapid period consistent with that of an inertial oscillation. The results appeared in the December 2005 edition of Icarus, the International Journal of Solar System Studies, accompanied by images of Uranus observed with the Keck II telescope in Hawaii. Those images, which appeared on the cover of Icarus, are generally acknowledged to be the most detailed ground-based images ever produced. Sromovsky and Fry produced the images and wrote the article, “Dynamics of cloud features on Uranus.”
AERIs and aerosols—Each year, SSEC scientists find new ways of using the complex interferometric instrument known as the AERI. In 2005, they found that observations in two parts of AERI’s measured spectrum, the 8-13 um window and the 3-4 um window, are sensitive to changes in amount of aerosols in the atmosphere. Atmospheric aerosols typically consist of both small and large particles, and the relative number of the small to large particles, as well as the total number of particles, is important for climate research and to investigate the health effects of these aerosols. SSEC researchers Dave Turner and Leslie Moy are working on a technique to retrieve the relative number of coarse (large) to fine (small) aerosols using AERI observations, which are sensitive to the larger particles, with observations from an instrument that is sensitive to aerosols of all sizes, the multi-filter rotating shadow-band radiometer (MFRSR). The technique has much promise under clear sky conditions.
Global Surface Emissivity Database—Eva Borbas and Suzanne Seeman expanded the global surface emissivity database to high spectral resolution. The database is based upon a principal component analysis of 313 laboratory-measured emissivity spectra of common terrestrial materials, together with input from the satellite-based MODIS MOD11 operational land surface emissivity product. Monthly land surface emissivity is derived at 0.05 degree spatial resolution for 413 wavelengths between 3.6 and 14.3 microns (approximate spectral resolution 5 wavenumbers). This expands upon the previous moderate spectral resolution version (pictured here for February 2003 for 4.3 and 8.3 microns) which included only 10 wavelengths between 3.6 and 14.3 microns.
UW Hybrid Model update—The UW Hybrid Isentropic Coordinate Modeling Group, led by Emeritus Professor Donald Johnson, has combined their model with a chemical model developed at NASA’s Langley Research Center. The new model, the Regional Air Quality Modeling System (RAQMS), focuses on ozone assimilation; the group found that including more sophisticated chemistry greatly reduces bias. This new global and regional chemical modeling and data assimilation system provided global meteorological and chemical forecasts to NASA for the Intercontinental Chemical Transport Experiment-North America, showing areas of pollution.
Using CRAS for past storms—On November 10, 1975, Lake Superior swallowed the cargo ship Edmund Fitzgerald, along with her 29 crewmembers and cargo of almost 26,000 tons of ore. The tale of the wreck evolved into a Midwestern legend. Thirty years later, Bob Aune recreated the storm using the latest forecast technology. Aune says these models normally require satellite data, so the biggest challenge was in building this model from other data sources. Besides validating the CIMSS Regional Assimilation System (CRAS), an experimental numerical weather prediction model, Aune’s case study will be used to teach fundamental winter storm dynamics in Professor Steve Ackerman’s basic meteorology course in Madison.
Polar winds in the news—MODIS Polar Winds work by Jeff Key and Chris Velden appeared in several news stories during 2005. NASA’s online newsletter Earth Observatory recently acknowledged the importance of CIMSS’s polar winds research in the improvement of weather forecasting. Useful for calculating the speed, height and direction of winds in the earth’s polar regions, satellite data fills in observational gaps and significantly extends a mid-range forecast’s scope of accuracy. NASA also uses the winds data, which made the cover story in the December 2004 issue of the Joint Center for Satellite Data Assimilation’s quarterly newsletter. Pat Pauley, a professor with the Navy’s post-graduate school, used the polar winds product in her research for the Navy. In an article posted on February 21, NASA’s Earth Observatory featured an article about the fifth anniversary of NASA’s Terra satellite. Included in the list of major advances achieved using Terra data, the article mentions the Cooperative Institute for Meteorological Satellite Studies’s (CIMSS) research on MODIS polar winds.
Stoughton tornadoes —While most individuals with an iota of sense heeded a barrage of warnings and headed for safety before the tornado outbreak on August 18, 2005, some of SSEC ’s self-proclaimed “weather weenies” did the opposite. As threatening clouds formed near SSEC’s home in the Atmospheric, Oceanic and Space Sciences building on the UW-Madison campus, Alex Harrington and a handful of intrepid weather lovers grabbed cameras and cell phones before hopping in their cars for a little storm chasing.
Courtesy of Bill Bellon (SSEC), Jason Brunner (CIMSS), and Wayne Feltz (CIMSS), anyone can relive the experience through an interactive case study of the remarkable southwestern Wisconsin weather event, which includes first-hand pictures and harrowing personal accounts from SSEC-employees-turned-storm-chasers (and others). Created as a learning tool for workshops hosted by CIMSS, the Web page also features animations derived from GOES satellite data that show clouds forming over southwestern Wisconsin and then moving on across the state.
Monitoring storms in Wisconsin—Using data from the tornado outbreak in southwestern Wisconsin on August 18, 2005, Kris Bedka demonstrated the stand-alone value of satellite-derived products to forecasters for thunderstorm growth prediction. These particular products constitute an element in an aviation safety system for thunderstorm avoidance being developed by the Federal Aviation Administration (FAA) and CIMSS researchers in the Advanced Satellite Aviation Weather Products (ASAP) program. Bedka applied the products to the data from August 18 and found that an individual forecaster relying solely on satellite information could have identified the precursors to predict the severe thunderstorms and tornados that eventually occurred. The case study demonstrated that ASAP satellite-derived thunderstorm monitoring and nowcast products can identify characteristics of pre-storm environmental flow, in addition to cumulus cloud typing, movement and growth indicators.
Volcanic ash—ASAP researchers have developed a technique to identify volcanic ash using GOES-12 imagery and new automated four-channel technology. The Four Channel Volcanic Ash Mask identified an eruption of the Santa Ana volcano in El Salvador. The imagery of the eruption also demonstrated that this product can distinguish volcanic clouds from neighboring thunderstorms, which look similar in visible and infrared bands. This technique looks for ice clouds significantly contaminated with aerosol. If used in operations, the method would have resulted in a more timely warning for the Santa Ana eruption.
Toward better weather information—CIMSS researchers used the mobile weather lab housed in the AERIbago to test the quality of measurements taken from the Tropospheric Airborne Meteorological Data Reporting (TAMDAR) instrument in February and March of 2005. The TAMDAR AERIbago Validation Experiment (TAVE) took place at the Memphis Tennessee Air National Guard facility, with Wayne Feltz (CIMSS) in charge of CIMSS’s TAVE operations.
A record season—Every year, the CIMSS Tropical Cyclones group provides many real-time products to the National Hurricane Center and other government organizations. In the record-breaking 2005 hurricane season, their efforts earned commendation from the National Hurricane Center. The group creates and improves technology that helps meteorologists use satellite data to better understand the characteristics of tropical cyclones. Their work results in more accurate forecasts and, consequently, more effective warnings for the public.
Providing valuable information—As Hurricane Rita intensified on September 21, 2005, the Tropical Cyclones team provided the National Hurricane Center with invaluable information. The reconnaissance plane scheduled to fly into the storm on the night of the 20th experienced technical difficulties and turned back. During this time, a computer procedure developed at CIMSS called the Advanced Objective Dvorak Technique indicated a rapid intensification. Chris Velden noticed this and notified the crew at the National Hurricane Center. His contribution appeared in the hurricane center’s online discussion: “Satellite images indicate that the cloud pattern is typical of an intense hurricane. ... T-numbers from ... the University of Wisconsin CIMSS are peaking near 7.0 on the Dvorak scale.” The technique uses digital infrared information to create a profile for a storm including its strength and probable path.
Popular montages—Based on a technique developed by NOAA’s Gary Wade stationed at SSEC, the Tropical Cyclones research team generates a “hurricane montage” product that displays the path of each tropical cyclone using snapshot images of the storm during its lifetime. As a storm traverses the ocean basin the montage procedure continually modifies the area of coverage to capture the lifecycle of the developing storms. The product is available on the CIMSS Tropical Cyclones Web site in real time with an archive of various montage images for selected storms.
Featured animation—The National Climate Data Center used an animation of Hurricane Katrina on their page devoted to hurricane climatology. Rick Kohrs of SSEC’s McIDAS development team produced the animation. The page also links to CIMSS’s Tropical Cyclones team’s Web page for Hurricane Katrina.