Contact: Lynn Chandler
NASA/Goddard Space Flight Center–EOS Project Science Office

Rob Gutro/ Harvey Leifert
American Geophysical Union Press Room

New Earth science insights by scientists at NASAís Goddard Space Flight Center (Greenbelt, Md.) will be reported at the Fall 2000 American Geophysical Union meeting in San Francisco this week. Listed below are some of the discussions that are open to the news media. All presentations will be held at the Moscone Convention Center.

Lower Dust Absorption of Sunlight —
The ability of dust to absorb solar radiation and heat the atmosphere is one of the main uncertainties in climate modeling and the prediction of climate change. Dust absorption is not well known due to limitations of in situ measurements. Two new independent remote sensing techniques are discussed that assess the impact of dust on climate. Yoram Kaufman will present the results of his findings on Friday, December 15 at 1:30 p.m. in Room MC 123.

What Controls the Arctic Lower Stratosphere Temperature? —
Stratospheric temperature determines springtime ozone loss. This talk demonstrates for the first time how lower atmospheric weather and climate can change the temperature of the polar stratospheric regions. Paul Newman will present the results of his findings on Saturday, December 16 at 4:20 p.m. in Room MC 125.

Measurements and Predictions of Atmospheric Influences from the Very Large July 14-16, 2000, Solar Proton Event —
A large solar flare with an associated coronal mass ejection occurred in mid-July and caused a very large solar proton event at the earth between July 14-16, 2000. So far this is the largest solar storm of solar cycle 23. The solar proton fluxes were measured by instruments aboard the GOES-10 satellite and used in our proton energy deposition model to help quantify the energy input to the middle atmosphere during this large solar event. The measured and modeled impacts of this solar event will be compared and discussed in this paper. Charles Jackman will present the results of his findings on Monday, December 18 at 4:15 p.m. in Room MC 135.

Results from Terra, NASA’s Earth Observing System —
NASAís Terra spacecraft, launched on December 18, 1999, marked a new phase in climate and global change research. Terra is the flagship observatory for the NASA’s Earth Observing System and has scientific instruments to gain information about the Earth’s land, oceans and atmospheres and their relation to climate change with unprecedented accuracy. John Ranson will present biospheric results at 8:30 a.m. Tuesday, December 19 in Room MC 301 and Yoram Kaufman will present the atmospheric results on the same day at 1:30 p.m. in Room MC 131.

What Causes the Break Up of Antarctic Ice Shelves? —
The dramatic disintegration of sections of the Antarctic ice shelves in recent years has been attributed to a rise in mean annual temperatures over the past half century, although no specific mechanism has been found linking the two. New findings identify the culprit: summertime surface meltwater fills small crevasses and drives them open, weakening the ice shelf and making it vulnerable to breakup by winds and tides. Christina Hulbe will present the new findings on Friday, December 15 at 11:05 a.m. in Room MC 104.