HR: 13:40h
AN: A43E-01    [Abstracts]
TI: Particulate Organic Matter Downwind of the NE U.S. and its Role in Light Extinction and the Relative Humidity Dependence of Light Extinction during ICARTT
AU: * Quinn, P K
EM: patricia.k.quinn@noaa.gov
AF: NOAA PMEL, 7600 Sand Point Way NE, Seattle, WA 98115
AU: Bates, T S
EM: tim.bates@noaa.gov
AF: NOAA PMEL, 7600 Sand Point Way NE, Seattle, WA 98115
AU: Coffman, D J
EM: derek.coffman@noaa.gov
AF: NOAA PMEL, 7600 Sand Point Way NE, Seattle, WA 98115
AU: Onasch, T
EM: onasch@aerodyne.com
AF: Aerodyne Research, Inc., 45 Manning Rd., Billerica, MA 01821
AU: Baynard, T
EM: tbaynard@al.noaa.gov
AF: NOAA AL, 325 Broadway, Boulder, CO 80305
AU: Pettersson, A
EM: apettersson@al.noaa.gov
AF: NOAA AL, 325 Broadway, Boulder, CO 80305
AU: Osthoff, H
EM: Hans.Osthoff@noaa.gov
AF: NOAA AL, 325 Broadway, Boulder, CO 80305
AU: Ravishankara, A
EM: ravi@al.noaa.gov
AF: NOAA AL, 325 Broadway, Boulder, CO 80305
AU: Covert, D
EM: dcovert@u.washington.edu
AF: University of Washington, 4909 25th Ave NE, Seattle, WA 98105
AU: Sierau, B
EM: Bsierau@u.washington.edu
AF: NOAA AL, 325 Broadway, Boulder, CO 80305
AU: Wang, W
EM: weiwang@uiuc.edu
AF: University of Illinois, 205 N. Mathews, Urbana, IL 61801
AU: Rood, M
EM: mrood@uiuc.edu
AF: University of Illinois, 205 N. Mathews, Urbana, IL 61801
AB: Measurements during the Tropospheric Aerosol Radiative Forcing Experiment (TARFOX) and the New England Air Quality Study (NEAQS 2002) revealed large mass fractions (18 to 80 percent) of particulate organic matter (POM) in the submicron aerosol downwind of the northeastern United States. This same result was observed during ICARTT (International Consortium for Atmospheric Research on Transport and Transformation) which took place in the Gulf of Maine in July and August of 2004. A priority onboard the NOAA RV Ronald H. Brown during ICARTT was the characterization of the POM, its role in light extinction, and its effect on the relative humidity dependence of light extinction. Measurements were made of non-refractory organic matter (Aerodyne aerosol mass spectrometer), total organic carbon (TOC) (Sunset Labs thermo-optical carbon analyzer), water soluble organic carbon (WSOC) (Sievers Total Organic Carbon Analyzer), light scattering (nephelometer), absorption (particle soot absorption photometer), and extinction (Cavity Ring Down Extinction Cell), and the relative humidity dependence of light scattering and extinction, f(RH) (humidified nephelometer and CRD extinction cell). The ratio of WSOC to TOC covered a wide range from near 0 to near 1 with a mean value of 0.63 +/- 0.15. Based on a multiple linear regression, experiment-wide mass scattering efficiencies for non-sea salt sulfate and OC were 7.2 and 11 m2 g-1, respectively. In general, lower values of f(RH) were observed when organics dominated the submicron aerosol mass while higher values were observed when sulfate dominated the mass. These results will be discussed in the context of the prevailing meteorology and origin of the sampled air masses.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0345 Pollution--urban and regional (0305)
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting