HR: 14:40h
AN: A43E-05    [Abstracts]
TI: In-Situ Measurements of Aerosol Optical Properties using new Cavity Ring-Down -- Results From Two Recent Field Missions
AU: * Hallar, A
EM: ahallar@mail.arc.nasa gov
AF: NASA Ames Research Center/ National Research Council, MS 245-4, Moffett Field, CA 94035 United States
AU: Strawa, A
EM: astrawa@mail.arc.nasa.gov
AF: NASA AMES Reasearch Center, MS 245-4, Moffett Field, CA 94035 United States
AU: Covert, D
EM: dcovert@u.washington.edu
AF: University of Washington, 4909 25th Ave NE, Seattle, WA 98105 United States
AU: Jonsson, H
EM: staff@cirpas.net
AF: Center for Interdisciplinary Remotely Piloted Aircraft Studies, 3200 Imjin Rd., Hangar #507 , Marina, CA 93933 United States
AU: Kirchstetter, T W
EM: twkirchstetter@lbl.gov
AF: Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, MS70-108B, Berkeley, CA 94720 United States
AU: Schmid, B
EM: bschmid@mail.arc.nasa.gov
AF: Bay Area Enviromental Research Institute, NASA AMES MS 245-5, Moffett Field, CA 94035 United States
AU: Luu, A P
EM: aluu@mail.arc.nasa.gov
AF: San Jose State University, NASA Ames MS 245-4, San Jose, CA 94035 United States
AU: Redemann, J
EM: jredemann@mail.arc.nasa.gov
AF: Bay Area Enviromental Research Institute, NASA AMES MS 245-5, Moffett Field, CA 94035 United States
AU: Bokarius, K
AF: San Jose State University, NASA Ames MS 245-4, San Jose, CA 94035 United States
AB: Carbonaceous species (BC and OC) are responsible for most of the absorption associated with aerosol particles. The amount of radiant energy an aerosol absorbs has profound effects on climate and air quality. It is ironic that aerosol absorption coefficient is one of the most difficult aerosol properties to measure. A new cavity ring-down (CRD) instrument, called Cadenza (NASA-ARC), measures the aerosol extinction coefficient for 675 nm and 1550 nm light, and simultaneously measures the scattering coefficient at 675 nm. Absorption coefficient is obtained from the difference of measured extinction and scattering within the instrument. A study was recently conducted in the Caldecott Tunnel, a heavily-used tunnel located north of San Francisco, CA. The aerosol sampled in this study was characterized by fresh automobile and diesel exhaust. Measurements from Cadenza and from an aethalometer are presented. The aethalometer is a filter-based photometer and the near infrared channel is calibrated to produce a measure of BC mass loading. Cadenza also measured during a recent airborne campaign EVE (Extended Wavelength Modis Validation), based in Marina, California. The timing of this experiment is chosen to coincide with the maximum transport of Asian dust to the US West coast. Results and comparisons of Cadenza with other types of instrumentation will be presented.
DE: 0305 Aerosols and particles (0345, 4801)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting