High Spectral Resolution Instruments Advance Science
by Terri Gregory, SSEC Public Information Coordinator
This issue of
News covers SSEC news and events mostly from June 2002. Also see Fire
News for July. Use images freely with credit to the Space Science
and Engineering Center, University of WisconsinMadison.
Aqua, the second of NASAs Earth observing research satellites, was launched on May 4 and is successfully sending data about Earths water cycle. The satellite follows Terra, launched in December 1999, which emphasizes the earths land and atmospheric features. The U.S. collaborated with Japan and Brazil to design and build Aqua. NASAs Goddard Space Flight Center, Jet Propulsion Laboratory and Langley Research Center each provided an instrument as did Japans and Brazils 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 Earths Radiant Energy System) team, SSEC director Henry Revercomb serves on the AIRS (Atmospheric Infrared Sounder) science team.
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, SSECs ground-based instrument noted for its high vertical resolution, akin to that of a radiosonde, which gives a profile of the Earths temperature, pressure and other elements.
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 Earths atmosphere. Liam Gumley, manager of SSECs
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
GIFTSCurrently 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 NASAs New Millennium Program. According to Tom Achtor, SSECs 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 NOAAs National Environmental Satellite, Data, and Information Service and National Weather Service. ABS-HESCIMSS scientists and Tim Schmit (NOAA, at SSEC) have devised an algorithm that properly converts 16-bit longwave hyperspectral radiance and brightness temperature data (heat that the earth emits to space) from original 32-bit data for compression studies of NOAAs proposed Hyperspectral Environmental Sensor (HES, formerly referred to as the Advanced Baseline Sounder). The HES is the proposed sounding instrument on the next-generation geostationary operational weather satellite. Hyperspectral refers to satellite instruments with 1000s of channels. Current instruments (GOES Sounder, MODIS) have tens of channels. Using simulated data computed by NOAA/ORA to represent the data from the AIRS instrument on the Aqua satellite, a quantization study was performed on the longwave data. The object was to convert the raw longwave radiances into brightness temperatures (K) and quantize these values into 16-bit integers while retaining an accuracy of 0.01 K. Researchers will use these data sets to investigate lossless data compression of hyperspectral infrared data.
PIFTSThe 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.
AntarcticaAntarctic projectsThe Antarctic Automatic Weather Station (AWS) and Antarctic Meteorological Research Center projects held their annual meeting on May 2122 in Madison. About 30 attendees included participants in NSFs research program and users of AWS data. Those users include forecasters, researchers and teachers. They represent a variety of organizations, including the U.S. Coast Guard, Raytheon Polar Services, Meteo France, Pennsylvania State University, University of Chicago, University of Alaskas Geophysical Institute, Lyndon State College, and Ohio State University.
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:
Glaciologist Douglas MacAyeal, University of Chicago, is a close colleague of the UWMadison 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.
Wendler, of the University of Alaskas Geophysical Institute
in Fairbanks, Alaska, studies Antarcticas 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.
May 10, Linda Keller (Department of Atmospheric and Oceanic Sciences),
working with SSECs 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
Data and ImageryMODISThe latest from NASAs Earth Observatory (06/4/2002), a weekly update of satellite-related news, reported or listed four different SSEC news events. They are all in this edition of In the News.
SnowThe Schwerdtfeger Library, SSECs 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 UWMadison Libraries, was made available in May to scientists and the general public.
VISITviewCIMSS computer scientist Thomas Whittaker has made available to researchers and weather forecasters around the world real-time satellite image collaborations that can be used on line with many sorts of weather satellite data including GOES (U.S.), GMS (Japan, for all Asia), Meteosat (Europe and Africa), and Derived Product images. According to Whittaker, a Java-enabled Web browser and a phone (or a voice-over-the-net connection like the voice chat on Yahoo! Messenger) enables scientists to share and discuss the latest imagery. The satellite image collaborations were set up for the VISIT Project, using the VISITview teletraining and collaboration software written for the NWS using weather satellite imagery already available on line.
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 Europes weather from Ft. Collins, CO. Weather forecasters
at the Australian Bureau of Meteorology discussed GMS (Asian) images.
Forty conference attendees checked out the worlds weather with VISITview.
Field ExperimentsIHOPLest you think field experiments are boondoggles to exotic places, review the pictures from the Homestead, OK AERIBAGO IHOP site where the Atmospheric Emitted Radiance Interferometer (AERI) was based during the International H2O Project (IHOP) 2002. Click on Homestead Site Pictures for a view of the landscapefairly featureless but full of exciting weather. SSECs Scanning High-resolution Interferometer Sounder (Scanning-HIS) was based in Oklahoma City with a companion instrument, the (National Polar Orbiter Environmental Satellite System Atmospheric Sounder Testbed-Interferometer (NAST-I), developed by NASAs Langley Research Center near Hampton, Virginia. The National Center for Atmospheric Research led this large thunderstorm investigation that covered the southern Great Plains from Texas to Kansas. The University of WisconsinMadisons SSEC participated with many other universities. The AERI was able to collect data at times when companion instruments, the NAST-I and the Scanning-HIS, flew overhead on research aircraft. Together they provided good data on atmospheric convective conditions, those that exist before thunderstorms.
CIMSS IHOP ScienceJim 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 NASAs 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 Feltzs hand), primarily writing about the National Severe Storms Laboratory. Reporter Diane Clay noted that many scientists worked in IHOP 2002.
ALEXI in SMEXUWMadison 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 landprimarily 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 its wet and where its not, making it a good remote sensing tool to test techniques that measure soil moisture and to guide field experiment activities.
Neutrino NewsCheck out the newly redesigned IceCube Web site, with links to IceCube news, its brochure (in PDF format), an expanded outreach section and other features.
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 CaliforniaBerkeley 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 SSECs 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 scienceImpact of polar cloud track winds from MODIS on ECMWF analyses and forecasts will be included in the forthcoming American Meteorological Societys 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 (NOAAs Office of Research and Applications, working at SSEC), and David Santek and Chris Velden (both with CIMSS).
CASPRJeff 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 711.
ModelingBob Aune (NOAA, at SSEC) is evaluating the use of
data from NASAs 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.
Pretty whorlsImagery 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.
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 stormJoe 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.
Summer weather expertsOn 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 GuysThe June 24 Weather Guys appearance on Larry Meillers 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 degreesEurope, 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, OutreachScholarsSix Wisconsin winners of the fifth annual Verner E. Suomi Scholarship Award for Outstanding Achievement in the Physical Sciences were announced in June. Seth Bruch of Arrowhead High School (Hartland, WI), Sean McLaughlin of Wauwatosa East High School, Kelly M. Sheahan of Neenah High School, Adam Varble of Franklin High School (Franklin, WI), Greta Videen of Rice Lake High School, and Nicholas Zachar of Hudson High School each received a $1000 scholarship. CIMSS and NOAA have offered the Suomi Scholarship since 1998 to honor Professor Verner E. Suomis lifelong commitment to the education of undergraduate students. This year more than 40 students applied for the prestigious award, which recognizes outstanding achievement in the physical sciences. To be eligible a student must be a graduating high school senior who plans to attend a University of WisconsinSystem undergraduate program in the physical sciences, especially meteorology, earth science, oceanography, physics, astronomy, science or math education, environmental science and engineering. Contact Leanne Avila for more information.
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.
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.
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.
SSECs Data Center supported Steve Fossetts 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.
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
NASAs DC-8, based at Dryden Flight Research Center, will appear at the Experimental Aviation Associations annual convention in Oshkosh, Wisconsin from July 23-29. SSECs Scanning-HIS is one of the science instruments that rides on the aircraft, and it is expected to be on board then.
This issues 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, MeteorologyUnderstanding the Atmosphere, by Steven A. Ackerman and John A. Knox, © 2002, ThomsonBrooks/Cole.