HR: 08:00h
AN: A21E-01    [Abstracts]
TI: Climate Change Science Program Synthesis and Assessment Reports: Aerosol Properties and Their Impacts on Climate
AU: * DeCola, P
EM: pdecola@nasa.gov
AF: National Aeronautics and Space Administration, Science Mission Directorate, Washington, DC 20546 United States
AU: Moss, R
EM: Richard.Moss@pnl.gov
AF: Climate Change Science Program, 1717 Pennsylvania Avenue NW, Suite 250, Washington, DC 20006 United States
AB: The Climate Change Science Program (CCSP) is developing and extending its research activities to support policymaking and adaptive management. The program includes a set of "Synthesis and Assessment Products," active participation in international assessments such as those of the Intergovernmental Panel on Climate Change, improvements in modeling and other resources to facilitate comparison of response options, and development, with users, of tools to support adaptive management and planning. These efforts are building on substantial ongoing efforts of agencies and departments participating in the CCSP. One of the products focuses on aerosol properties and their impact on climate. The very complex mixture of aerosol types and their spatial distributions provide diverse warming and cooling influences on climate, and impact the formation of both water droplets and ice crystals in clouds. Our poor understanding of aerosol properties and distributions results in large uncertainties about the net impact of aerosols on climate and impairs our ability to project climate changes. The product will be produced in two phases: Phase-I aims for a few explicit and focused scientific "review nuggets" in the near term that would be not only stand alone as CCSP-facilitated products, but that would also be useful input to community-wide activities like the IPCC and Phase-II that would connect and focus the new (2006/7) level of community-wide understanding of climate change (and aerosol-climate inclusively) to explicit decision-support information and tools. In this light, we have embarked on Phase I of a synthesis product entitled, "Aerosol properties and their impacts on climate," which addresses Goal 2, "Improve quantification of the forces bringing about changes in the Earth's climate and related systems," under the Strategic Plan of the CCSP. We present here the status of this first phase of work, which is focused on new assessment and synthesis information stimulated by the CCSP. Three topics have been selected as foci and will be reported on here: (1) dependence of radiative forcing by tropospheric aerosols on aerosol composition in the North Atlantic, North Pacific, and North Indian Ocean based on in-situ observations, (2) a review of measurement-based understanding of aerosol radiative forcing and aerosol sources derived from the analysis of remote-sensing observations, and (3) a model intercomparison study to quantify the uncertainties associated with indirect aerosol forcing. This work will feed in to the next IPCC assessment and serve as an input to Phase II of the product, which will focus on issues of special concern to North America.
DE: 6620 Science policy
DE: 0305 Aerosols and particles (0345, 4801)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting