Michael Braukus
Headquarters, Washington, D.C.
(Phone:  202/358-1547)                                                
September 23, 1992

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

RELEASE:  92-155

SCIENCE EXPEDITION TARGETS NEW ATMOSPHERIC OZONE POLLUTION 

   More than 200 scientists from 13 countries are participating 
in a science expedition, spearheaded by NASA, to investigate 
newly discovered concentrations of harmful ozone over large 
regions of southern Africa and Brazil.

   Believed linked to massive biomass burning on the two 
continents, the pool of ozone pollution was recently uncovered 
by satellite analysis.  Biomass burning is the consumption by 
fire of forests or fields.  Unlike stratospheric ozone, which is 
a critical shield against harmful ultraviolet radiation, ozone 
in the lower atmosphere is a pollutant.

   Investigation of the new phenomenon will employ a variety of 
high-tech instrumentation including observations from 
satellites, aircraft and ground platforms.  The field campaign, 
which began in mid-September, will extend through most of 
October.

   In addition to satellite surveillance, NASA's DC-8 "flying 
laboratory" from the Ames Research Center, Mountain View, 
Calif., will participate.  The Space Shuttle Endeavour, on its 
September mission, photographed African and South American smoke 
palls to provide new visual perspective on the nature of the 
emissions.

   The South American iinvestigation is a joint effort between 
the space agencies of the United States and Brazil.  Satellites, 
specially instrumented Brazilian aircraft, the NASA DC-8 and 
balloon-borne sampling platforms will be used to address the 
source areas in central Brazil and track the long-range 
distribution of gases as they move into the southern tropical 
Atlantic.


                            - more -
                             - 2 -


   The African portion of the experiment is a collaboration of 
European, African and North American scientists to investigate 
fires in savanna (grassland containing scattered trees and 
undergrowth) in southern Africa, movement of fires across that 
continent and the relationship between fires, savanna ecology 
and atmospheric chemistry.  Measurements from ground, tower, 
balloon and airborne platforms will be integrated with data from 
the Brazilian investigation and with satellite observations.

   Scientists in both projects acknowledge that the movements 
and chemical mechanisms of this ozone anomaly are extremely 
complex and that explanations up to this point have been 
speculative.  These new investigations will be the first to 
provide concrete insights on the global impact of tropical 
biomass burning.

   Some scientists believe the effects of emissions from the 
biomass burning on the atmosphere's chemistry are comparable to 
those from fossil fuels in the northern latitudes.  The 
emissions from the burning undoubtedly have some effect on the 
Earth's climatic balance, but whether this could lead to net 
warming or cooling is still open to speculation.  

   Scientists should get a better understanding of the processes 
involved in these mechanisms when the data are analyzed and 
interpreted.

                            - end -