HR: 17:30h
AN: A14B-07 [Abstracts]
TI: Cloud Properties Derived from Visible and Near-infrared Reflectance in the Presence of
Aerosols
AU: * Pilewskie, P
EM: Peter.Pilewskie@lasp.colorado.edu
AF: University of Colorado - Boulder
University of Colorado-Boulder, Laboratory for Atmospheric and Space Physics
Program in Atmospheric and Oceanic Science
Campus Box 311
, Boulder, CO 80309-0392
United States
AU: Hofmann, O
EM: odele.hofmann@lasp.colorado.edu
AF: University of Colorado - Boulder
University of Colorado-Boulder, Laboratory for Atmospheric and Space Physics
Program in Atmospheric and Oceanic Science
Campus Box 311
, Boulder, CO 80309-0392
United States
AU: Kindel, B
EM: kindel@cires.colorado.edu
AF: University of Colorado - Boulder
University of Colorado-Boulder, Laboratory for Atmospheric and Space Physics
Program in Atmospheric and Oceanic Science
Campus Box 311
, Boulder, CO 80309-0392
United States
AU: Gore, W
EM: Warren.Gore@nasa.gov
AF: NASA Ames Research Center, MS 245-4, Moffet Field, CA 94035-1000
United States
AU: Russell, P
EM: Philip.B.Russell@nasa.gov
AF: NASA Ames Research Center, MS 245-4, Moffet Field, CA 94035-1000
United States
AU: Livingston, J
EM: jlivingston@mail.arc.nasa.gov
AF: SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025
United States
AU: Redemann, J
EM: jredemann@mail.arc.nasa.gov
AF: Bay Area Environmental Research Institute, 560 Third St. West, Sonoma, CA 95476
United States
AU: Bergstrom, R
EM: bergstrom@baeri.org
AF: Bay Area Environmental Research Institute, 560 Third St. West, Sonoma, CA 95476
United States
AU: Platnick, S
EM: Steven.Platnick@nasa.gov
AF: NASA Goddard Space Flight Center, Code 913, Greenbelt, MD 20771
United States
AU: Daniel, J
EM: john.s.daniel@noaa.gov
AF: NOAA Aeronomy Laboratory, 325 Broadway, Boulder, CO 80305
United States
AU: Garrett, T
EM: tgarrett@met.utah.edu
AF: University of Utah, 135 S 1460 E, Salt Lake City, UT 84112-0110
United States
AB:
The New England Air Quality Study - Intercontinental Transport and Chemical Transformation (NEAQS-ITCT) experiment conducted
in July-August 2004 included objectives on the effects of urban-industrial pollution aerosols on cloud radiative properties,
the so-called indirect effect. Measurements of spectral irradiance covering the near-ultraviolet to near-infrared were made
from two airborne platforms, the NOAA WP-3D and the Sky Research J-31, using identical Solar Spectral Flux Radiometers
(SSFR). The SSFR measured the upwelling and downwelling spectral irradiance between 380-1670 nm from which the spectral
albedo (ratio of upwelling to downwelling) and net (difference between downwelling and upwelling) irradiance were derived.
Cloud spectral albedo was used to retrieve cloud particle effective radius, optical depth, and liquid water path. The
robustness of the optical retrieval method will be examined by comparing the WP-3D SSFR retrievals to in situ
measurements made with an FSSP-100 and an OAP 2D-C and to an independent retrieval using Miniaturized Differential Absorption
Spectroscopy (MIDAS), also on board the WP-3D.
A sunphotometer was also deployed on the J-31, the14-channel NASA Ames Airborne Tracking Sunphotometer (AATS-14), providing
aerosol optical depths at thirteen discrete wavelengths between 354-2138 nm. J-31 flights on 15, 20, and 31 July were of
particular interest because AATS-14 data revealed the presence aerosol layers above clouds. Comparisons between SSFR-derived
cloud properties and MODIS cloud retrievals were in close agreement when aerosol optical depth was less than 0.1. Over
moderately thick clouds there is evidence that an enhanced aerosol layer, such as that encountered during the 20 July case,
may affect the retrieved cloud properties. Such an influence must be distinguished from a true "aerosol indirect effect" in
order to accurately quantify the amount by which aerosols modify cloud albedo.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0319 Cloud optics
DE: 0321 Cloud/radiation interaction
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005