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2008 News Releases

Longwood participates in international experiment on global warming

May 27, 2008

Longwood professor Walter Witschey and his son, Walter II, in front of the albedo patch they made to participate in an international experiment related to global warming. Longwood professor Walter Witschey and his son, Walter II, in front of the albedo patch they made to participate in an international experiment related to global warming.

Longwood University was one of 20 institutions around the world that participated recently in an experiment to raise awareness of global warming.

As part of the Albedo Experiment, the result of a partnership between NASA and the International Action on Global Warming (IGLO) project, Longwood joined with other science centers, museums and schools to create highly reflective – high albedo – areas for satellite observation. The experiment measured changes in the earth’s reflectance of sunlight and heat energy, called albedo, by creating mock polar ice caps out of available white material, aiming to show the ice caps’ importance in regulating earth’s temperature.

In Longwood’s project, an albedo patch consisting of 400 square meters of Tyvek was installed May 17 on Iler Field by Dr. Walter Witschey, professor of anthropology and science education, and his son, Walter II, a Ph.D. student in biophysics at the University of Pennsylvania. Two NASA satellites then passed over the campus in formation 30 minutes apart, taking digital images of the area.

“This area of Iler Field was transformed from one of low albedo to high albedo in 80 minutes,” the elder Witschey said. “Polar ice caps and cloud tops have a high albedo, green forest canopies a low albedo. Even with very small changes, for small patches of land, you can noticeably alter the albedo. We wanted to show that you can have a measurable effect on planetary values.”

Beginning about 10 that morning, the father-son team unfurled nine strips of Tyvek, a high-strength paper product made by Dupont to wrap houses, each strip of which was 100 feet long and five feet wide. The paper was unrolled onto the field and pinned in place with bricks and sod pins. The Landsat 7 satellite, used for land-use analysis, crop acreage measurements and other observations, passed over at 11:36 a.m., followed at 12:06 p.m. by the TERRA satellite, which has an instrument, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), that measures the heat coming off the earth.

“The satellites, which are 440 miles up, fly in formation, moving as though hooked together by a string,” Witschey said. “They circle the earth taking images of the earth as part of their mission. The Landsat 7 takes images of an area 115 miles wide. ASTER is a collaborative effort between NASA and Japan’s Ministry of  Economics, Trade and Industry.”

Results of the overflights are being compiled by NASA and the Association of Science-Technology Centers (ASTC), an international organization of science centers and museums dedicated to furthering the public understanding of science. Participants will be able to compare before and after images from space and analyze the results thanks to software provided by NASA.

Longwood’s involvement in the Albedo Experiment stemmed from Witschey’s affiliation with ASTC, of which he is a past president. IGLO, launched in March 2007, is a project of ASTC.

The experiment took place from May 15-24 at sites in 11 foreign countries and various locations throughout the United States. Some sites set up for as many as three satellites, other sites only one. “Other sites did different things, though each involved some sort of moderate white surface,” Witschey said.

Participating institutions included sites in Australia, Belgium, Finland, France, Israel, Italy, Japan, Norway, Singapore, Sweden and Wales. Longwood was one of only six sites in the U.S. One of the others was the Science Museum of Virginia, where Witschey was director for 15 years before coming to Longwood in 2007.