PROGRAM TITLE:  	Earth Probes/Total Ozone Mapping Spectrometer (TOMS)
ACTIVITY STREAMS:	Observations & Data Management
SCIENCE ELEMENT:	Climate and Hydrologic Systems
				Solar Influences  
				Global Observing Systems

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

SCIENTIFIC MERIT:  The TOMS Earth Probe missions (planned for 
1994, 1996 and 1998) will continue the high-resolution global 
mapping of total stratospheric ozone which began in 1978 with the 
TOMS instrument on Nimbus-7 and followed in 1991 with the TOMS 
instrument on the Soviet Meteor-3 weather satellite.  TOMS 
measurements are vital to the continuing effort to monitor and 
understand the dynamics of stratospheric ozone depletion.  The 
continuation of ozone measurements is important for the separation 
of the effects of the 11-year solar cycle from steady or linear trends 
due to CFC's and other trace gases. Theory predicts that the solar-
cycle effects at middle and low latitudes is comparable over the 
period of one solar cycle.  However, differentiating the causes of the 
variations will require data extending as far into the next solar cycle 
as possible.  Although the TOMS data will be used primarily to study 
these processes, the information gained will contribute to the 
achievement of other science objectives.  The total ozone pattern 
measured by TOMS can be used in studies of severe storms to infer 
the circulation patterns of the jet stream near the tropopause level.  
TOMS ozone data can also be use for atmospheric correction of ocean 
color measurements of pigment concentrations, studies of the UV 
reflectivity of the Earth's surface, and development of cloud 
climatology.  Because the amount of ozone can be affected by 
volcanic eruptions, which generate sulfur dioxide in the Earth's 
atmosphere, TOMS is designed to perform global mapping of this 
transient gas.  Sulfur dioxide is rapidly transformed into sulfate 
aerosols which may persist in the stratosphere for months to years.  
Its effects in the stratosphere may be associated with climate change.  
TOMS data on volcanic eruptions will make valuable contributions to 
studies in several disciplines, including volcanology, meteorology, 
and atmospheric chemistry. 

STAKEHOLDERS: The TOMS program is coordinated with the UN 
Environmental Program (UNEP) and through the World Meteorology 
Organization (WMO) with participation by NOAA, NASA and EPA for 
global ozone change monitoring in accordance with the Montreal 
Protocol.  Also, the  FAA is interested in TOMS data to assist in air 
traffic routing (viz., for jet stream location and tracking volcanic ash 
clouds).

POLICY RELEVANCE:	
Primary	- Stratospheric Ozone and UV-B Radiation
				
Secondary	- Climate Change and Global Warming

PROGRAM CONTACT:	
Lenwood G. Clark			
Dr. Jack Kaye
Office of Mission to Planet Earth  Code YS
NASA Headquarters, Code YF		358-0757
tel: 202-358-0786
fax: 202-358-2769
E-Mail: L.CLARK.NASA/omnet