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Measurement and Modeling of Vertically Resolved Aerosol Optical Properties and Radiative Fluxes Over the ARM SGP SiteIn order to meet one of its goals - to relate observations of radiative fluxes and radiances to the atmospheric composition - the Department of Energy's Atmospheric Radiation Measurement (ARM) program has pursued measurements and modeling activities that attempt to determine how aerosols impact atmospheric radiative transfer, both directly and indirectly. However, significant discrepancies between aerosol properties measured in situ or remotely remain. One of the objectives of the Aerosol Intensive Operational Period (TOP) conducted by ARM in May 2003 at the ARM Southern Great Plains (SGP) site in north central Oklahoma was to examine and hopefully reduce these differences. The IOP involved airborne measurements from two airplanes over the heavily instrumented SGP site. We give an overview of airborne results obtained aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft. The Twin Otter performed 16 research flights over the SGP site. The aircraft carried instrumentation to perform in-situ measurements of aerosol absorption, scattering, extinction and particle size. This included such novel techniques as the photoacoustic and cavity ring-down methods for in-situ absorption (675 nm) and extinction (675 and 1550 nm) and a new multiwavelength, filter-based absorption photometer (467, 530, 660 nm). A newly developed instrument measured cloud condensation nucleus concentration (CCN) concentrations at two supersaturation levels. Aerosol optical depth and extinction (354-2139 nm) were measured with the NASA Ames Airborne Tracking 14-channel sunphotometer. Furthermore, up-and downwelling solar (broadband and spectral) and infrared radiation were measured using seven individual radiometers. Three up-looking radiometers werer mounted on a newly developed stabilized platform, keeping the instruments level up to aircraft pitch and roll angles of approximately 10(exp 0). This resulted in unprecedented continuous vertical profiles of radiative fluxes, which we will compare to modeled fluxes using the aforementioned data as input.
Document ID
20040013508
Document Type
Preprint (Draft being sent to journal)
Authors
Schmid, B.
(Bay Area Environmental Research Inst. Sonoma , CA, United States)
Arnott, P.
(Desert Research Inst. Reno, NV, United States)
Bucholtz, A.
(Naval Research Lab. Monterey, CA, United States)
Colarco, P.
(Maryland Univ. Greenbelt, MD, United States)
Covert, D.
(Washington Univ. Seattle, WA, United States)
Eilers, J.
(NASA Ames Research Center Moffett Field, CA, United States)
Elleman, R.
(Washington Univ. Seattle, WA, United States)
Ferrare, R.
(NASA Langley Research Center Hampton, VA, United States)
Flagan, R.
(California Inst. of Tech. Pasadena, CA, United States)
Jonsson, H.
(Center for Interdisciplinary Remotely-Piloted Aircraft Studies Marina, CA, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Subject Category
Optics
Distribution Limits
Public
Copyright
Other
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