Organization: National Science Foundation (NSF)

Research Title: Global Tropospheric Chemistry Program

Funding Level (millions of dollars):

FY94 12.4
FY95 12.8
FY96 12.4

Committee on Environment and Natural Resources (CENR) Component:
(a) Subcommittee: Global Change Research Subcommittee (100%) NSTC Committee on Fundamental Science
(b) Environmental Issue: Chemically Induced Changes (100%);
(c) Research Activity: System Structure and function: Understanding (80%); Prediction (20%)

Organizational Component:
Directorates for Geosciences and Mathematical and Physical Sciences
Division of Atmospheric Sciences
National Science Foundation
4201 Wilson Boulevard
Arlington, VA 22230

Point of Contact:
Jarvis Moyers
Phone: 703-306-1522

Research Goals:
To provide an improved understanding of how chemically and radiatively important substances of natural and anthropogenic origin enter the atmosphere, are physically and chemically transformed, and are ultimately removed.

Research Description:
The Global Tropospheric Chemistry Program is a focused atmospheric chemistry program designed to provide a better understanding of how substances of natural or anthropogenic origin enter the atmosphere, are physically and chemically transformed, and ultimately removed. The overall objective of this program is to measure, understand, and thereby predict changes in the chemistry of the global atmosphere with particular emphasis on changes affecting the radiative properties and oxidizing capacity of the atmosphere and the atmospheric component of biogeochemical cycles. This objective is to be accomplished through field and laboratory investigations as well as theory aided by appropriate statistical and mathematical modeling. Available funds will be used to permit NSF supported scientists at the Universities and the National Center for Atmospheric Research to participate in major international regional field experiments in FY 1995 through FY 1999 and to identify, analyze, and develop mathematical and statistical models of atmospheric chemistry that can be used for process understanding and climate prediction purposes. Laboratory investigations of the mechanisms and rates of atmospheric chemical reactions of climatic importance will also be supported under this program. A portion of the program's funds will be used to help offset the costs of development, procurement, and evaluation of advanced instrumentation required for future observational projects. Major GTCP activities, including aircraft and land-based field observations to investigate the atmospheric cycles of carbon, nitrogen, sulphur, and oxidant species, and the development of tropospheric chemistry models, have been and are currently being planned and scheduled for the period 1995-1999.

Program Interfaces:

Program Milestones:
GTCP participation in multi-agency and international field projects scheduled for 1995 and beyond include studies of surface exchange processes in the tropics; photochemistry experiments in the atmosphere over the Atlantic and Pacific oceans; and studies of the role of atmospheric sulfur compounds on the distribution of aerosols and on the physical properties of clouds.

Policy Payoffs:
In the short-term, field, laboratory, and theoretical tests will allow identification of greenhouse gas sources, sinks and lifetimes, the role of anthropogenic sulfate aerosols in offsetting trace-gas greenhouse warming, and an improved understanding of the factors which control the oxidizing capacity of the atmosphere. Incorporation of these and other chemical processes in global chemistry and climate models will improve predictions and assessments of future changes in atmospheric composition and the resulting impact such changes may have on climate forcing.