High Spectral Resolution Instruments Advance Science

Also In the News...

Antarctica

Data and Imagery

Field Experiments

Neutrino News

Polar Science

Weather Events

Weather Experts

Education, Honors, Outreach

News Errata

Et Cetera

In the Wings

Aqua, the second of NASA’s Earth observing research satellites, was launched on May 4 and is successfully sending data about Earth’s water cycle. The satellite follows Terra, launched in December 1999, which emphasizes the earth’s land and atmospheric features. The U.S. collaborated with Japan and Brazil to design and build Aqua. NASA’s Goddard Space Flight Center, Jet Propulsion Laboratory and Langley Research Center each provided an instrument as did Japan’s and Brazil’s national space agencies. Scientists from many institutions participated in science teams for each U.S. instrument. NOAA scientist W. Paul Menzel represents SSEC on the MODIS (Moderate Resolution Imaging Spectroradiometer) team, NASA scientist Bryan Baum also is stationed at SSEC and serves on the CERES (Clouds and the Earth’s Radiant Energy System) team, SSEC director Henry Revercomb serves on the AIRS (Atmospheric Infrared Sounder) science team.

Artist's conception of the Aqua satellite (NASA)

According to SSEC director Hank Revercomb, “our task now is to determine how to use and interpret the direct observations [from the satellite].” He notes that the AIRS has “improved vertical resolution by a factor of three,” or, provides three times the detail of current sounding instruments. Revercomb said that “AIRS is the first instrument that employs high resolution to give global coverage of temperature, water and ozone daily. It gives radically higher spectral resolution with greatly improved vertical information, like an AERI in space,” referring to the Atmospheric Emitted Radiance Interferometer, SSEC’s ground-based instrument noted for its high vertical resolution, akin to that of a radiosonde, which gives a profile of the Earth’s temperature, pressure and other elements.

MODIS images from the Aqua satellite will look much like this one from Terra. Click for a full-resolution image showing fires and smoke in Quebec, Canada on July 8, 2002.

Aqua carries both a high-spatial resolution imager, MODIS, that gives greater detail in the horizontal, and a high-spectral resolution sounder, AIRS, that gives greater detail in the vertical so that, according to Revercomb, “we can see smaller things and measure more layers, at the same time.”

Looking forward to future satellite developments, Revercomb said that, “Although Aqua represents a great leap forward, it is not an end, but a beginning. We need to continue improving our observations and our ability to turn them into better weather forecasts. People will always want more and better information about the weather and climate.”

SSEC will begin to receive and process raw data in near real time from the MODIS instrument onboard Aqua as soon as direct broadcast is routinely activated on the spacecraft. SSEC will also receive raw data from AIRS, AMSU (Advanced Microwave Sounding Unit), and HSB (Humidity Sounder for Brazil) instruments, and will work towards near real-time processing as soon as possible. According to NASA, the three instruments are “used together to determine vertical profiles of water vapor,” or how much and where water vapor lies in different levels of Earth’s atmosphere. Liam Gumley, manager of SSEC’s MODIS direct broadcast facility, explained that SSEC will work closely with the team at the NASA Jet Propulsion Laboratory that built the AIRS to create products that can be released to the scientific community. Gumley hopes to be creating usable products from Aqua instruments “routinely and automatically” by the end of this year. NASA headquarters is funding preparation of the processing software for release to the international direct broadcast community, the last step in releasing data to the scientific community.

Next Steps

GIFTS—Currently SSEC collaborates with NASA, the State University of Utah, the Navy and NOAA to develop GIFTS, the Geosynchronous Imaging Fourier Transform Spectrometer, a program that originated within NASA’s New Millennium Program. According to Tom Achtor, SSEC’s executive director for science, “we are designing a plan to receive the entire GIFTS raw data stream at the Center, process and archive all data, apply software algorithms to create meteorological products and participate in evaluation of the data with NOAA’s National Environmental Satellite, Data, and Information Service and National Weather Service.”

• SDL GIFTS
  

PIFTS—The Planetary Imaging Fourier Transform Spectrometer (PIFTS) is being designed to measure reflected sunlight and heat radiation of planets including the Earth. The design idea has achieved a milestone with production of a breadboard, or preliminary instrument. The PIFTS breadboard provides an opportunity to gain experience with real imaging FTS data that can help to evaluate instrument design trades, calibration procedures, and data handling algorithms that may be needed in future systems. As part of the report on breadboard development, principal investigator Lawrence Sromovsky compared PIFTS data with that from the AERI in clear-sky conditions. Excellent agreement was shown between an imaging Fourier Transform Spectrometer (FTS), the PIFTS, and a single detector FTS, the AERI.

Antarctica

AWS data has been supplied since 1980, when University of Wisconsin meteorology professor Charles Stearns put up his first weather station. The data was always supplied to researchers in Antarctica and in recent years has expanded to include anyone interested in the continent, including school children. Current users who attended this annual meeting include:

• Art Cayette and others of the U.S. Space and Naval Warfare group use AWS data for weather forecasting, especially for flights into and from Antarctica.
• Paul Pettre of Meteo France/CNRH uses AWS and AMRC data for climatology studies.
• David Reusch, Penn State, simulates AWS data using analyses from the European Centre for Medium-range Weather Forecasts and a Neural Network.
• Sean McPhilamy and others of the U.S. Coast Guard help with AWS deployment and maintenance and use the data to forecast their own flights and voyages.

Glaciologist Douglas MacAyeal, University of Chicago, is a close colleague of the UW–Madison group who uses AWS and AMRC data to observe tabular icebergs. He and Jonathan Thom installed equipment on icebergs to track their movements and has used the data to animate the movements of large iceberg B-15A. MacAyeal will correlate iceberg movements with seismic events. He noted that the iceberg did move during a Peruvian earthquake, but is not certain that the quake caused the movement.

Austin Hogan, professor emeritus at Lyndon State College has used AWS data for air chemistry forecasts for a field party at the South Pole during the late 1990s into 2000. He and Pam Grube-Hogan have begun to develop a forecast tree. Thay have found interesting characteristics in weather patterns, especially in the transition from winter to “summer” weather at the South Pole.

Gerd Wendler, of the University of Alaska’s Geophysical Institute in Fairbanks, Alaska, studies Antarctica’s katabatic winds, fiercer than anywhere else on earth. In 1992, four automatic weather stations were placed along the coast of Adélie Land, where the strongest winds blow. He and fellow researchers obtained three months of good data before a strong storm destroyed three of the four stations. With those few months, the group did show where the strongest winds blew and how hard. Interestingly, the areas of strongest winds were not necessarily the coldest. Wendler also studies the surface heat budget, which he measured in the summer sea-ice pack. Antarctica, because of its role as a heat sink, is important in climate studies.

Icebergs—On May 10, Linda Keller (Department of Atmospheric and Oceanic Sciences), working with SSEC’s Antarctic Meteorological Research Center, noticed that a crack in the Ross Ice Shelf had calved Iceberg C-19. According to University of Chicago glaciologist Douglas MacAyeal, it is “about the 5th to the 10th largest iceberg in the grand list of ‘largest icebergs ever.’”

Data and Imagery

Snow—The Schwerdtfeger Library, SSEC’s campus special library, has scanned and cataloged all collected photomicrographs of Wilson Alwyn Bentley, who took the first pictures of snow and ice crystals. The collection, made possible in part with a grant from the Friends of UW–Madison Libraries, was made available in May to scientists and the general public.

Ice crystal 0031 in the Bentley collection.

This particular application of VISITview technology was used for the first time on May 23 with a one-hour real-time global satellite data briefing at the Asia-Pacific Satellite Applications Training Seminar, a World Meteorological Organization conference in Melbourne, Australia. Tom Whittaker gave a PowerPoint overview of VISITview from home in Madison, WI; Mark DeMaria used GOES-W satellite imagery in a briefing from Boulder, CO; Tony Mostek (COMET) and Scott Bachmeier (CIMSS) and Bob Aune (NOAA) used Meteosat-5 in a discussion of eastern Europe’s weather from Ft. Collins, CO. Weather forecasters at the Australian Bureau of Meteorology discussed GMS (Asian) images. Forty conference attendees checked out the world’s weather with VISITview.

Field Experiments

CIMSS IHOP Science—Jim Nelson and Tony Schreiner (Cooperative Institute for Meteorological Satellite Studies, CIMSS) and Tim Schmit and Gary Wade (NOAA) supported IHOP with a variety of satellite-derived products. These included Cloud Top Pressure and Effective Cloud Amount measurements, retrieved from the Geostationary Operational Environmental Satellite (GOES)-11. The data were produced until GOES-11 was returned to storage mode on June 21, 2002.

Among the products prepared for IHOP researchers was a Java viewer to see the weather conditions and flight path on any day during the experiment.

Dryden Flight Research Center, home of NASA’s DC-8 research aircraft, included the Scanning-HIS in its IHOP2002 news release, along with the other research instruments flying on the plane.

The Daily Oklahoman newspaper used an image of hail (in researcher Wayne Feltz’s hand), primarily writing about the National Severe Storms Laboratory. Reporter Diane Clay noted that many scientists worked in IHOP 2002.

SMEX—SSEC participated with its Scanning-HIS in the 2002 Soil Moisture Field Experiment, a collaborative venture of NASA’s Earth Science Enterprise and the U.S. Department of Agriculture’s (USDA) Agricultural Research Service. The experiment, based in Iowa, studied land-atmosphere interactions while validating new instrument technologies including those on NASA’s new Aqua satellite. Early afternoon research flights were timed to coincide with the Aqua orbit, which passes over the equator at 1:30 p.m., local time, heading north. The S-HIS flew on NASA’s DC-8 to obtain high-resolution infrared radiance spectra. The experiment lasted from July 1 through July 8.

ALEXI in SMEX—UW–Madison scientists in CIMSS and Soil Science are working with William P. Kustus of the USDA to supplement moisture and vegetation measurements taken with instruments and satellites during SMEX. The UW group, George Diak and John Mecikalski (CIMSS) and John Norman (Soil Science), will use microwave measurements with their own physical measurements of vegetation to produce a data set for use in numerical models. From their observations taken on clear days they will find sensible and latent heat fluxes and surface moisture indexes that Kustus will use in large eddy simulation models. These fine-scale models try to predict fluxes at the surface of the land—primarily changes in temperature, moisture, and momentum. Scientists hope that their measurements will lead to better forecast models of fast growing and quickly changing thunderstorms.

According to team leader George Diak, while it is fairly easy to predict that thunderstorms will occur, it is extremely difficult to predict where and when. The USDA hopes that remote sensing will make that task easier. The ALEXI model is developed at CIMSS to evaluate flux measurements at a 5 kilometer scale. Researcher John Mecikalski says it “gives a snapshot of where it’s wet and where it’s not,” making it a good remote sensing tool to test techniques that measure soil moisture and to guide field experiment activities.

Neutrino News

AMANDA and IceCube are mentioned in Wired magazine in an article focusing on the new South Pole station. The contemporarily designed new buildings are being constructed now. Neutrino scientists are among researchers who stay in Antarctica during winter. The article ran in the July issue of Wired.

The National Research Council (Washington, D.C.) successfully reviewed IceCube on June 24th and 25th. According to Nature magazine (May 2, 2002), another review is in progress. The White House has “asked the National Academy of Sciences for a study of the respective merits” of IceCube and another neutrino project, the National Underground Science Laboratory. Scientists agree that the two projects are completely different in their goals. The NAS has been asked to discover "any possible scientific reduncancy" in the two. Francis Halzen, IceCube Principal Investigator, notes that IceCube and its predecessor AMANDA have been reviewed many times.

SpaceDaily.com reports on the possibility of using Antarctica as an “excellent place to develop a sterile drill” before drilling in Mars, according to P. Buford Price, professor of physics at University of California–Berkeley and an AMANDA collaborator. The article draws on a paper by Price and other researchers in the U.S. and Russia, including Bruce Koci of SSEC’s Ice Coring and Drilling Service. The paper appeared in the Proceedings of the National Academy of Sciences for June 11. Price is a cosmic-ray physicist and also is investigating the possibility of finding microbes in ice and permafrost cores. As part of the AMANDA project and IceCube, holes are drilled down to 2.3 kilometers (or 1.4 miles) beneath South Pole Station.

Polar Science

Polar science—“Impact of polar cloud track winds from MODIS on ECMWF analyses and forecasts” will be included in the forthcoming American Meteorological Society’s 15th Conference on Numerical Weather Prediction, to be held in August in San Antonio, Texas. The authors are N. Bormann (European Centre for Medium-range Weather Forecasts, ECMWF), J.-N. Thepaut (ECMWF), Jeff Key (NOAA’s Office of Research and Applications, working at SSEC), and David Santek and Chris Velden (both with CIMSS).

CASPR—Jeff Key, NOAA scientist who leads the polar winds program at SSEC, has released a new version of the Advanced Very High Resolution Radiometer (AVHRR) retrieval products of surface, cloud and radiation characteristics for the Surface Heat Budget of the Arctic (SHEBA) experiment. The data is being used for meteorological case studies and in numerical models in the Arctic Climate Model Intercomparison Project.

Key and Xuan Ji Wang (a graduate student in CIMSS) have quantified Arctic trends in 18 years of data from the AVHRR instrument on the NOAA polar-orbiting satellite. The satellite data shows an overall increase in annual temperature (at the surface). This agrees with reported warming trends, but the satellite data shows that the temperature decreases in the winter months and increases at other times of the year. The AVHRR data also shows decreased clouds in winter but an increase in spring and summer, canceling each other over a year. Seasonal trends in surface temperature, surface albedo (amount of light reflected), and cloud amount do not give rise to trends in the amount of heat trapped or reflected by clouds nor in the amount of change in heat radiated or reflected. It appears that the decrease in sea-ice extent and albedo that results from surface warming modulates the cooling effect of increasing cloud amount, resulting in little or no change in the surface radiation budget. That is, overall, the Arctic is neither heating nor cooling.

Wang and Key are presenting the paper, “The Arctic Climate and Its Change Revealed by Surface and Cloud Properties and Radiation Fluxes Based on the AVHRR Polar Pathfinder Data Set” at the SPIE International Symposium on Optical Science and Technology in Seattle, Washington, July 7–11.

Numerical Modeling—Bob Aune (NOAA, at SSEC) is evaluating the use of data from NASA’s MODerate resolution Imaging Spectroradiometer MODIS) in a polar version of the CIMSS Regional Assimilation System (PCRAS) numerical model over Antarctica. The data (retrievals of total precipitable water and cloud-top pressure) are being used to adjust mixing ratio and cloud water in the forecast model during a 24 hour period (to initialize the forecast). About 800,000 observations at 5 km resolution were taken from each satellite pass over the south pole. Difference fields of total precipitable water (with and without MODIS) at the end of the 24 hour initialization period indicate that the MODIS data tends to “dry” the forecast model and reduce cloudiness in the coastal regions surrounding Antarctica.

The effect of assimilating MODIS total precipitable water (TPW) on the moisture field around Antarctica, as simulated with the polar version of the CIMSS Regional Assimilation System (PCRAS). Differences in TPW are shown (observations with MODIS subtracting those without MODIS) at the end of the 24-hr initialization period on December 7, 2000. The MODIS data reduced the amount of water vapor in the coastal regions (blue areas).

Weather Events

This true-color image received on May 28 shows ice breaking up along Canada’s Newfoundland Coast. While whispy in the image, the moving strands of ice floes are dangerous to ships trying to steer through them.

Pretty whorls—Imagery taken every five minutes from GOES-11 revealed vortices of about 10 to 50 kilometers (a tenth to a degree of longitude) in marine stratus clouds off the coast of southern California on June 6, 2002. Images of fog and stratus showed initial vortex development right before dawn, while imagery from the satellite's visible channel showed greater detail in the vortex structure during the first few hours of daylight. The circulation of an offshore Catalina Eddy was acting to slow the erosion of fog and stratus along the coastline.

NASA’s Earth Observatory Web site used an SSEC MODIS image to illustrate air quality over the Mid-Atlantic U.S. The true-color image shows haze blowing over most of the eastern seaboard and into the Atlantic Ocean on June 11, when the U.S. Environmental Protection Agency issued a code red warning for air quality over much of the Mid-Atlantic region.

Ice storm—Joe Barnard, Oklahoma City, used MODIS images of the January 31, 2002 ice storm which blanketed midwestern states in a presentation showing its impact on the electric power delivery infrastructure. He compared that storm with the May 3, 1999 tornado for his local chapter of IEEE (Institute of Electrical and Electronic Engineers), PES (Power Engineering Society).

Several articles about the tornado outbreak of May 3, 1999 were published in a special issue of the journal, Weather and Forecasting (June 2002, Volume 17, Number 3). Wayne Feltz and John Mecikalski, CIMSS, published a paper on the atmospheric state during the outbreak as profiled by the AERI instrument. Their analysis showed that “convective indices formed from AERI retrievals … diminished” as the storms developed. The issue itself includes articles from many disciplines and, as noted by Feltz, “may be of interest to anyone interested in extreme tornadic events.”

Weather Experts

Summer weather experts—On June 19, in preparation for the onset of summer weather, University Communications tipped the media to weather experts in the Atmospheric, Oceanic and Space Sciences building, including some from SSEC. The tip was placed on the AScribe wire service for transmission to news organizations. Dale Forbis, Wisconsin Radio Network, talked about summer weather with Tom Achtor, SSEC executive director for science.

Weather Guys—The June 24 Weather Guys appearance on Larry Meiller’s WHA radio show found Jonathan Martin (professor, Department of Atmospheric and Oceanic Sciences) fielding questions alone. Guest David Travis, who studies contrails, as does Steve Ackerman, who was not on the program, appeared for part of the show. They answered a question about contrails, which are persistent in the sky because of air traffic, not a government mind-control experiment, as some books indicate. They also fielded questions on where to find the perfect climate (defined as between 0 and 70 degrees—Europe, Martin suggested), how we know what the weather will be tomorrow, global warming and its impact on local climates, greenhouse gases, and the heat index.

Education, Honors, Outreach

Matthew Lazzara spoke July 9 at UW Space Place, to about 30 people. Lazzara, who runs the Antarctic Meteorological Research Center, talked about his experiences in Antarctica and on “Observing the Forbidding Continent from Earth and Space.” The talk was announced in University Communications’ News Briefs for July 5.

Tony Schreiner, CIMSS, was featured in NOAA Report and on Access NOAA for June as Team Member of the Month. Schreiner, who has worked at SSEC for 24 years, noted, “It is an honor and privilege to be nominated by my NOAA NESDIS peers, here at the advanced satellite products team.” His contributions include many cloud measurement products using GOES.

News Errata

EOSDIS Frustration, Space News (May/June 2002)—Rich Isaacman is not a Space News reporter, as is incorrectly stated, but rather works for Integral Systems, a private company and competitor to EOSDIS.

Maryland Tornado (May/June 2002)—The National Weather Service rescinded the initial F5 damage rating for the tornado that touched down at La Plata, MD. Still devastating, the tornado was reclassified to an F4.

Et Cetera

SurfaceQuality.com, who provides operator interfaces and other automated controls, also maintains a long list of engineering Web sites. SSEC was added in May, as a leader in satellite technology.

SSEC’s Data Center supported Steve Fossett’s successful around-the-world hot-air balloon flight with special composite imagery that covered the whole world. Bob Aune, NOAA researcher stationed at SSEC, provided background on the challenges of forecasting such a flight to Madison-based WISC-TV.

Stephen Crow, Punta Gorda, Florida, gave Tim Olander this feedback on the Tropical Cyclones Web site: “The best site for tropical weather!! Good work. I depend on you for a ton of info.” He sent this on July 3, when no hurricanes were active in the Atlantic or Caribbean.

In the Wings

NASA’s DC-8, based at Dryden Flight Research Center, will appear at the Experimental Aviation Association’s annual convention in Oshkosh, Wisconsin from July 23-29. SSEC’s Scanning-HIS is one of the science instruments that rides on the aircraft, and it is expected to be on board then.

This issue’s top story on high-spectral resolution instrumentation was written by Hank Revercomb, Tom Achtor, Liam Gumley, Tim Schmit and Terri Gregory. All else was compiled or written by Terri Gregory from a variety of sources.

To define or explain some terms, I used the textbook, Meteorology—Understanding the Atmosphere, by Steven A. Ackerman and John A. Knox, © 2002, Thomson–Brooks/Cole.

7-11-02 TG