Brian Dunbar
Headquarters, Washington, D.C.                                                
July 2, 1991
(Phone:  202/453-1547)

Jean W. Clough
Langley Research Center, Hampton, Va.
(Phone:  804/864-6122)


RELEASE:  91-103

NASA TO PROBE VOLCANO'S EFFECTS ON GLOBAL ATMOSPHERE


   The massive outpouring of volcanic material from Mount 
Pinatubo in the Philippines, believed by NASA scientists to be 
double that from any eruption in the last century, will draw a 
quick-response research team of NASA atmospheric scientists to 
the West Indian island of Barbados to gather information that 
should help evaluate the global atmospheric effects of this 
catastrophic event.

   Headed by Dr. M. Patrick McCormick of NASA's Langley 
Research Center, Hampton, Va., the special research team 
consists of other scientists from Langley; NASA's Ames 
Research Center, Mountain View, Calif.; the National Center 
for Atmospheric Research, Boulder, Colo.; and the Canadian 
Atmospheric Environment Service.  The mission also will be 
supplied with near real-time data from satellites and computer 
predictions of the volcano aerosol cloud locations.

   "Volcanic aerosols are climate 'forcers' so it is urgent we 
get an early characterization of the stratospheric plume," 
said McCormick.  "This effort will influence a number of 
future activities, including measurement scenarios for ground- 
and satellite-based sensors and development of chemical models 
of ozone depletion."

   Flying the NASA Lockheed Electra sampling platform, the 
group will take advantage of winds that are pushing giant 
pillars of smoke and gas toward the Caribbean.  NASA 
scientists will stage their operations out of Grantley Adams 
Airport, where a number of flights will probe the clouds with 
remote sensors aboard the Electra.

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   The team is scheduled to arrive on July 8.  Its primary 
focus will be to capture enough data about the composition, 
density and distribution of the volcanic clouds to form the 
basis for detailed analysis of potential global effects.  Data 
from the cloud also will be incorporated into studies to be 
conducted this fall by NASA and other groups during the second 
Arctic Airborne Stratospheric Experiment, which will study the 
processes of ozone depletion in the northern hemisphere.

   Instruments aboard the NASA Electra will measure plume 
base, thickness, particle shape, spatial distribution, total 
direct-diffuse radiation, optical depth and vertical columns 
of chemicals like sulfur dioxide and hydrogen chloride.
                             -end-