HR: 14:40h
AN: A13E-05    [Abstracts]
TI: Aerosol Composition and Morphology during the 2005 Marine Stratus Radiation Aerosol and Drizzle Study
AU: * Berkowitz, C M
EM: Carl.Berkowitz@pnl.gov
AF: Pacific Northwest National Laboratory, Atmospheric Sciences and Global Change Division, MS K9-30 PO 999, Richland, WA 99352 United States
AU: Jobson, T
EM: Tom.Jobson@pnl.gov
AF: Pacific Northwest National Laboratory, Atmospheric Sciences and Global Change Division, MS K9-30 PO 999, Richland, WA 99352 United States
AU: Alexander, M L
EM: Michael.Alexander@pnl.go
AF: Pacific Northwest National Laboratory, Chemical Structure and Dynamics Group, MS K8-88 PO 999, Richland, WA 99352 United States
AU: Laskin, A
EM: Alexander.Laskin@pnl.gov
AF: Pacific Northwest National Laboratory, Chemistry and Physics of Complex Systems Group, MS K8-88 PO 999, Richland, WA 99352 United States
AU: Laulainen, N
EM: Nels.Laulainen@pnl.gov
AF: Pacific Northwest National Laboratory, Atmospheric Sciences and Global Change Division, MS K9-30 PO 999, Richland, WA 99352 United States
AB: The composition and morphology of aerosols activated within cloud droplets relative to the properties of aerosols not activated is of central importance to studies directed at improved parameterization of the treatment of aerosols in large scale models. These models have many applications, including evaluations of the impact of anthropogenic aerosols on climate. To further our understanding of these aerosol characteristics, scientists from the U.S. Department of Energy Atmospheric Sciences Program (ASP) joined forces with participants of the Atmospheric Radiation Measurement (ARM) program's `Marine Stratus Radiation Aerosol and Drizzle Study' field campaign at Pt. Reyes, CA. Observations between July 4 and July 29, 2005 from the ASP in situ aerosol instruments and from the ARM Mobile Facility will be combined in a first look at the measurements made during this period. High time resolution measurements of size-dependent particle bulk composition (sulfate, nitrate, NH4, organics, etc ) were made using a time-of-flight aerosol mass spectrometer (TOF-AMS, Aerodyne Research). Aerosols were simultaneously collected using a transient aerosol collector (TRAC, PNNL) for subsequent single particle analysis to determine elemental composition and morphology. Particle measurements and collections were made both from ambient, dried air and through a conterflow virtual impactor (CVI) to compare composition of nucleated vs., non-nucleated particles. A CCN counter was also deployed to measure the fraction of cloud droplet kernels activated as CCN over a range of super-saturations. Our presentation will partition measurements into periods of cloudy and cloud-free periods. Measurements will also be partitioned between periods associated with a) northerly back trajectories that arrived at the Pt. Reyes site after passing along the Washington-Oregon coast, b) westerly oceanic trajectories and c) a very limited number of periods when the air flow appeared to be associated with urban areas to the south and southeast.
DE: 0320 Cloud physics and chemistry
DE: 0321 Cloud/radiation interaction
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005