Organization: National Aeronautics and Space Administration (NASA)

Research Title: Interdiciplinary Research and Analysis

Funding Level (millions of dollars):

FY94 5.0
FY95 13.1
FY96 35.2

Point of Contact:
Robert Curran
Phone: 202-358-1432
E-Mail: rcurran@hq.nasa.gov

Committee on Environment and Natural Resources (CENR) Component:
(a) Subcommittee: Global Change Subcommittee (100%) Task Group on Data and information Management
(b) Environmental Issue: Global change (80%); Air quality (20%)
(c) Research Activity: System structure and function: Observation (10%); Understanding (80%); Prediction (10%)

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

Research Goals:
To contribute to a comprehensive scientific assessment of the aerosol issue, including the sources of natural and anthropogenic aerosols, the transport and transformation processes, and the radiative and climatic effects. Interdisciplinary Research and Analysis Program

Research Description:
This program involves multiple disciplines ranging from analysis of aerosol sources, chemical transformations, satellite remote sensing, to modeling of global climatic effects. It has the following components:

Sources of natural and anthropogenic aerosols. A major issue to be resolved is the relative contribution of anthropogenically generated aerosols to regional and global backgrounds of natural aerosols in the troposphere. The relative contribution of anthropogenically-derived tropospheric aerosols to the natural background and variability on large regional to global scales are studied based on either process- oriented or modeling studies

Atmospheric transport and transformation processes. Research is conducted on the chemical composition and effects of tropospheric aerosols. This includes research on the chemical composition (elemental and isotopic) of tropospheric aerosols; nucleation and growth of aerosol particles; and chemical reactions occurring in or on the surface of the aerosol particles (including possible aerosol effects on the chemical composition of the atmosphere). Research is also conducted on the interrelationship of tropospheric meteorology, and the chemical, physical, and optical properties of the resulting aerosols.

Atmospheric radiation effects. The direct effect of aerosols in clear-sky conditions and the indirect effect on cloud formation processes and radiative properties are studied both observationally and theoretically. The studies include the interactions of aerosol composition, size, altitude, transport, and lifetime with their optical properties and effects on cloud optical properties.

Analyzing global aerosol distribution and evolution using satellite data. The focus of this effort is to quantify tropospheric aerosol loading and to measure its evolution, especially with respect to natural events such as volcano eruptions, dust clouds, cloud condensation nuclei production from sea-surface processes, as well as to assess the changes due to anthropogenic influences including pollution episodes and biomass burning.

Modeling the climatic consequences of aerosols. The sensitivity of the climate system to tropospheric aerosol forcing is studied with large scale numerical models. The experiments provide information to the observing community on the space-time sampling and types of measurements needed in order for the modelers to represent the actual aerosol climatic effects with reasonable fidelity.

Program Interfaces:
This program is part of the NASA's Mission to Planet Earth project to study the natural and anthropogenic impact on climate. Its interfaces with national and international programs include United States Global Change Research Program (USGCRP), World Climate Research Program (WCRP), and International Geosphere and Biosphere Program (IGBP).

Program Milestones:

Policy Payoffs:
(a) Enhanced understanding of the aerosol issue including the sources, the global distribution, and the chemical transformation. (b) Improved representation of aerosol radiative forcing for use in climate models. (c) Assessment of the potential aerosol climatic effect.