Climate Change Researchers Glimpse the New Millenium

LONG BEACH, California, January 11, 2000 (ENS) - Weather scientists from around the country are presenting climate change research this week at the 80th Annual Meeting of the American Meteorological Society. Conference attendees are taking a close look at how new technologies and innovative models can provide a clearer picture of the effects of global warming in the new millennium.

The American Meteorological Society (AMS) chose as its theme, "Applying Environmental Science to Societal Needs in the New Millennium." Numerous talks are highlighting technological and theoretical breakthroughs that could bring the causes of global warming into focus, and suggest possible solutions.

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An artist's rendition of NASA's Tropical Rainfall Measuring Mission satellite (All photos courtesy NASA)
Three new Earth observing spacecraft from the National Aeronautic and Space Administration (NASA) will launch innovative "lidar" instruments into orbit beginning this fall. Lidars send pulses of light energy from a laser through the atmosphere and measure the speed and the amount of light that returns. The signal's roundtrip time is a direct measure of the distance to the object.

M. Pat McCormick, co-director of the Center for Atmospheric Sciences at Hampton University, is the Remote Sensing Lecturer for this year's meeting. His lecture, "Remote Sensing from Space Using Occultation and Lidar Techniques," will be presented on Wednesday.

"Most instruments that scientists use to observe the Earth from space cannot see through even thin clouds or their view is distorted by clouds," says McCormick. "Many surface features and important phenomena in the lower atmosphere are completely hidden. Lidar can pierce many types of clouds and its very small beam can pass between clouds."

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NASA's TRMM satellite system has shown that forest fires (red) inhibit rainfall (blue)
For the first time, scientists will be able to peer inside forests across the world, accurately measure changes in the amount of ice in the polar caps, and get a global look at how clouds and airborne dust particles affect global warming.

A researcher at Colorado State University believes that regional assessments of climate change in the U.S. and one prepared by a United Nations panel overlook factors that are critically important to the realism of models of global climate change.

Roger Pielke Sr., professor of atmospheric science, and colleagues have shown in their research that the effect of landscape and human caused land-use changes can have a profound effect on climate variability and change. This work calls into question the realism of the climate predictions used in the U.S. regional, national and international assessments because these factors have not been included in the model.

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This image of the U.S. east coast was taken by one of NASA's Polar Orbiting Operational Environmental Satellites
"If land-use change is as important on the climate system as our results suggest, there is a large uncertainty in the future climate, since there is no evidence that we can accurately predict the future landscape," Pielke said.

A new approach to modeling regional impacts of climate change produces accurate simulations of the 1993 U.S. floods and 1988 drought, says NASA scientist Michael Fox-Rabinovitz. He will present his findings Thursday in a talk titled "Regional Climate Simulation of the Anomalous U.S. Climate Events with a Variable Resolution Stretched Grid GCM."

NASA scientists have completed the first globally complete long term data set for use in understanding El Niño/La Niña events, which some scientists associate with global climate change. The data set, part of the Global Precipitation Climatology Project (GPCP), is a result of rainfall analysis that examines precipitation monthly around the globe over a 20 year period.

The GPCP Project Scientist, Dr. Robert Adler of NASA’s Goddard Space Flight Center, will present the analysis Wednesday.

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NASA's GOES satellite system produced this 1998 image of Hurricanes Madeline and Lester over Mexico
This data is a result of combining information from a number of polar orbiting satellites, geosynchronous satellites and rain gauge information to give the best analysis of global precipitation on a monthly time scale. The polar orbiting Defense Meteorological satellites carry the Special Sensor microwave/Images instrument designed to estimate precipitation. The geosynchronous satellites are the Geosynchronous Operational Environment Satellites (GOES) from the U.S., the Meteosat from Europe and the Geosynchronous Meteorological Satellites (GMS) from Japan. Data from NASA’s recently launched Tropical Rainfall Measuring Mission (TRMM) spacecraft also is used to validate the global analyses.

According to Adler, these globally averaged values and the regional and time-varying patterns are extremely important as validation for computer models of the global atmosphere.

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This image of the U.S. east coast was taken by one of NASA's Polar Orbiting Operational Environmental Satellites (Photo courtesy NASA)
"Before we can use these models to successfully predict El Niño's and other climate phenomena they must be able to reproduce these observations," stated Adler. " With this information, we can better understand these phenomena and the critical regional precipitation variations associated with them."

Just as the El Niño-Southern Oscillation affects broad areas of the globe, there are anomaly patterns based in mid-latitudes that change the weather in large areas of the Northern Hemisphere. NASA will present a poster on, "A Global Precipitation Perspective on Persistent Extratropical Flow Anomalies," highlighting research by NASA scientists Adler, George Huffman and David Bolvin. The poster shows how the accompanying changes in the storm tracks rearrange the precipitation patterns, using two cutting edge global precipitation data sets that the authors recently developed. This analysis has the advantage of relating the known precipitation effects over land to the total pattern over land and ocean.

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The 1997-98 El Niño/La Niña spawned the largest bloom of microscopic algae ever seen in the Pacific Ocean, visible in this false color image as a green swath (Photo courtesy NASA)
Although significant advances have been made on how land surfaces and plant cover influence local rainfall, more work is needed on global climate models before they can produce accurate simulations of land-atmosphere interactions, says NASA scientist Yogesh Sud. He will present his findings Wednesday in a talk titled, "Land-Atmosphere Interactions: Successes, Problems, and Prospects."

NASA will offer "Electronic Theater 2000: Visions of Earth and Space", at the symposium as well. The exhibit will display the latest animations of the La Niña hurricanes - Floyd, Georges, Mitch, Bonnie and others - from GOES and TRMM satellites and GOES 3-D stereo animations of Oklahoma City and Salt Lake City tornadic thunderstorms. The Theater will also show dust storms in Africa and huge smoke plumes from raging fires in Mexico. More information is available at: http://rsd.gsfc.nasa.gov/rsd/ETheater/