Radiative Flux Changes by Aerosols from North America, Europe, and Africa over the Atlantic Ocean: Measurements and Calculations from TARFOX and ACE-2
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Authors
Russell, P.B.
Hignett, P.
Livingston, J.M.
Schmid, B.
Chien, A.
Bergstrom, R.
Durkee, P.A.
Hobbs, P.V.
Bates, T.S.
Quinn, P.K.
Subjects
AEROSOLS
MARINE METEOROLOGY
OPTICAL THICKNESS
ATLANTIC OCEAN
RADIANCE
RESEARCH AIRCRAFT
TROPOSPHERE
CLIMATOLOGY
ATMOSPHERIC MODELS
MARINE METEOROLOGY
OPTICAL THICKNESS
ATLANTIC OCEAN
RADIANCE
RESEARCH AIRCRAFT
TROPOSPHERE
CLIMATOLOGY
ATMOSPHERIC MODELS
Advisors
Date of Issue
1998-09
Date
Sep 07, 1998
Publisher
Language
Abstract
Aerosol effects on atmospheric radiative fluxes provide a forcing function that is a major source of uncertainty in understanding the past climate and predicting climate change. To help reduce this uncertainty, the 1996 Tropospheric Aerosol Radiative Forcing Experiment (TARFOX) and the 1997 second Aerosol Characterization Experiment (ACE-2) measured the properties and radiative effects of American, European, and African aerosols over the Atlantic. In TARFOX, radiative fluxes and microphysics of the American aerosol were measured from the UK C-130 while optical depth spectra, aerosol composition, and other properties were measured by the University of Washington C-131A and the CIRPAS Pelican. Closure studies show that the measured flux changes agree with those derived from the aerosol measurements using several modelling approaches. The best-fit midvisible single-scatter albedos (approx. 0.89 to 0.93) obtained from the TARFOX flux comparisons are in accord with values derived by independent techniques. In ACE-2 we measured optical depth and extinction spectra for both European urban-marine aerosols and free-tropospheric African dust aerosols, using sunphotometers on the R/V Vodyanitskiy and the Pelican. Preliminary values for the radiative flux sensitivities (Delta Flux / Delta Optical depth) computed for ACE-2 aerosols (boundary layer and African dust) over ocean are similar to those found in TARFOX. Combining a satellite-derived optical depth climatology with the aerosol optical model validated for flux sensitivities in TARFOX provides first-cut estimates of aerosol-induced flux changes over the Atlantic Ocean.
Type
Preprint
Description
Fifth International Aerosol Conference; 14-18 Sep. 1998; Edinburgh, Scotland; United Kingdom
Series/Report No
Department
Organization
Ames Research Center
Identifiers
NPS Report Number
Sponsors
Funder
RTOP 622-44-10-10
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.