Organization: National Aeronautics and Space Administration (NASA)

Research Title: Atmospheric Chemistry Modeling and Analysis Program (ACMAP)

Funding Level (millions of dollars):

FY94 7.5
FY95 6.7
FY96 5.7

Committee on Environment and Natural Resources (CENR) Component:
(a) Subcommittee: Global Change Research Subcommittee (100%) Risk Assessment Group Task Group on Observations and Data Management
(b) Environmental Issue: Stratospheric ozone; Tropospheric ozone; Greenhouse gases; Surface Ultraviolet Radiation
(c) Research Activity: System structure and function: Understanding (60%); Prediction (30%); Integrated assessment (10%)

Organizational Component:
Atmospheric Science Branch
Office of Mission to Planet Earth
NASA Headquarters
Washington, DC 20546

Point of Contact:
Jack A. Kaye
Phone: 202-358-0757

Research Goals:
Develop coupled chemistry-transport models for the stratosphere and troposphere to simulate distribution of trace constituents in present and future atmosphere; analyze large data sets to improve understanding of atmospheric trace constituent distributions, including past evolution; reconcile changes in recent atmosphere using combination of data analysis and modeling

Research Description:
The two main areas of research in this program are data analysis and modeling. They are synergistically linked in that large global data sets can only be understood in the context of atmospheric models, while atmospheric models require global data sets for their evaluation and initialization.

Data analysis (40%): The program focuses on analysis of data on stratospheric dynamics and trace constituent composition as well as tropospheric trace constituent composition (tropospheric dynamics is covered by other programs within NASA's Office of Mission to Planet Earth). Data sets analyzed emphasize space-based remote sensing data and aircraft data, but also include rocket-, balloon-, and ground-based data. Space-based remote sensing data will be used to infer information about surface ultraviolet radiation.

Atmospheric modeling (60%): Stratospheric and tropospheric chemistry/transport model development, analysis, and evaluation is supported through this program. Models are used for both retrospective studies, in which changes in the atmosphere over the recent past are reconciled with results of models using assumed/known forcings, and for prognostic studies, in which scenarios for projected atmospheric forcing are used to drive models in the future. While in the past this program has focused mainly on stratospheric ozone as an end in itself, there is increasing emphasis on the role of ozone as a climate gas.

Program Interfaces:
The major interfaces of the ACMAP program are with other programs in the Office of Mission to Planet Earth at NASA, including the Upper Atmosphere Research Program, the Tropospheric Chemistry Program, and the Global Atmospheric Modeling and Assimilation Program, as well as the Mission Operations and Data Analysis and Earth Observing System Programs. ACMAP also interfaces closely with the Atmospheric Effects of Aviation Program supported by NASA's Office of Aeronautics. External interfaces include those with several components of NOAA (NMC, NESDIS, ERL, CMDL), DOE, EPA, and NSF. Linkage to the broader international scientific community is accomplished mainly through the Stratospheric Processes and their Role in Climate (SPARC) subgroup of the World Climate Research Program (WCRP) and the International Global Chemistry (IGAC) program of the International Global Biosphere Program (IGBP), as well as participation in externally-sponsored international assessments, such as the World Meteorological Organization/ United Nations Environment Programme (WMO/UNEP) ozone assessment and the Intergovernmental Panel on Climate Change (IPCC) climate assessment.

Program Milestones:
1994: Complete contributions to 1994 WMO/UNEP ozone assessment and IPCC interim assessment. 1995: Complete contributions to 1995 IPCC climate assessment. 1996 (tentative): Carry out follow-up NASA assessment on Concentrations, Lifetimes, and Trends of CFCs, Halons, and Related Molecules in the Atmosphere

Policy Payoffs:
(i) Better understanding of past atmospheric trace constituent change, including ozone distributions (total, stratospheric, and tropospheric) (ii) Improved models which can be used for assessments of future atmospheric response to trace gas forcing, including calculated effects on stratospheric and tropospheric ozone and aerosol distributions (iii) Development and application of scientific algorithms for inferring information on past and present distribution of surface ultraviolet radiation using space-based remote sensing data.