HR: 0800h
AN: A41A-0014    [Abstracts]
TI: In-Situ Measurements of Aerosol Optical Properties using new Cavity Ring-Down and Photoacoustic Instruments and Comparison with more Traditional Techniques
AU: * Strawa, A W
AF: NASA Ames Research Center, MS 245-4, Moffett Field, CA 94035 United States
AU: Hallar, A G
AF: NASA Ames Research Center, MS 245-4, Moffett Field, CA 94035 United States
AU: Covert, D
AF: University of Washington, 4909 25th Ave NE, Seattle, WA 98105 United States
AU: Elleman, R
AF: University of Washington, 4909 25th Ave NE, Seattle, WA 98105 United States
AU: Ferrare, R A
AF: NASA Langley Research Center, Mail Stop 401A , Hampton, VA 23681 United States
AU: Jonsson, H
AF: Center for Interdisciplinary Remotely Piloted Aircraft Studies, 3200 Imjin Rd., Hangar #507 , Marina, CA 93933 United States
AU: Luu, A P
AF: San Jose State, NASA Ames, Moffett Field, CA 94035 United States
AU: Ogren, J
AF: NOAA, 325 Broadway, Boulder, CO 80305 United States
AU: Ricci, K
AF: Los Gatos Research, 67 E. Evelyn Avenue, Suite 3, Mountain View, CA 94041 United States
AU: Schmid, B
AF: NASA Ames Research Center, MS 245-4, Moffett Field, CA 94035 United States
AU: Schmid, B
AF: Bay Area Research Institute, NASA AMES, Moffett Field, CA 94035 United States
AU: Arnott, P
AF: Desert Research Institute, 2215 Raggio Parkway , Reno, NV 89512 United States
AU: Castaneda, R
AF: NASA Ames Research Center, MS 245-4, Moffett Field, 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. Aerosol absorption coefficient is also measured by a photoacoustic (PA) instrument (DRI) that was operated on an aircraft for the first time during the DOE Aerosol Intensive Operating Period (IOP). This paper will report on measurements made with this new instrument and other in-situ instruments during two field recent field studies. The field study was an airborne campaign, the DOE Aerosol Intensive Operating Period (IOP) flown in May, 2003 over northern Oklahoma. One of the main purposes of the IOP was to assess our ability to measure extinction and absorption coefficient in situ. This paper compares measurements of these aerosol optical properties made by the CRD, PA, nephelometer, and Particle Soot Absorption Photometer (PSAP) aboard the CIRPAS Twin-Otter. During the IOP, several significant aerosol layers were sampled aloft. These layers are identified in the remote (AATS-14) as well as in situ measurements. Extinction profiles measured by Cadenza are compared to those derived from the Ames Airborne Tracking Sunphotometer (AATS-14, NASA-ARC). The regional radiative impact of these layers is assessed by using the measured aerosol optical properties in a radiative transfer model.
DE: 0305 Aerosols and particles (0345, 4801)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting