HR: 15:25h
AN: A13G-08    [Abstracts]
TI: The Pacific Dust Experiment (PaCDEX) Field Campaign: A summary of accomplishments during the field campaign and examples of early results.
AU: * Stith, J
EM: stith@ucar.edu
AF: National Center for Atmospheric Research, Box 3000, Boulder, CO 80307, United States
AU: Ramanathan, V
AF: Center for Atmospheric Sciences (CAS) Center for Clouds, Chemistry and Climate (C4) Scripps Institution of Oceanography (SIO) University of California, San Diego (UCSD), 9500 Gilman Drive, MC 0221, La Jolla, CA 92093, United States
AB: The Pacific Dust Experiment (PACDEX) is a pilot study utilizing quasi-Lagrangian sampling of the Asian dust and pollution plumes as they travel across the Pacific Ocean and interact with clouds and maritime weather systems. The NSF/NCAR G-V aircraft was used, guided by daily chemical forecasts, to follow dust events at various Pacific locations during the eastbound transit towards North America. Objectives of PACDEX include identification of the principal cloud-active and black carbon aerosols in the Asian plume, documenting changes in cloud hydrometeors in regions affected by the plumes, documenting the solar changes in the plume vertical structure in clear and cloudy regions, and examining differences in these variables among Western and Eastern Pacific plumes. Fourteen research flights were conducted in April and May 2007. Asian dust events were followed across much of the Pacific Ocean at altitudes from 11 km to near the surface. Cross-frontal sampling in several extratropical storms was conducted at multiple altitudes in regions where the plumes were found. Ice forming nuclei (IN) activation spectra (at various supersaturations and temperatures) were obtained in several dust regions, polluted regions, and in background air. Early results from the field project suggest that Asian dust serves as an important source of IN to maritime clouds, and that anthropogenic Asian emissions, particularly CO and black carbon, are effectively incorporated into the upper regions of extratropical storm clouds.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0321 Cloud/radiation interaction
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting