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Yoram J. Kaufman and Robert S. Fraser

1983, in final form 13 June 1983) ABSTRACY In order to utilize satellite measurements of optical thickness over land for estimating aerosol propertiesduring air pollution episodes, the optical thickness was measured from the surface and investi~ted. Aerosoloptical thicknesses have been derived from solar transmission measurements in eight spectral bands withinthe band X440-870 nm during the summers of 1980 and 1981 near Washington, DC. The optical thicknessesfor the eight

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L. A. Remer, Y. J. Kaufman, D. Tanré, S. Mattoo, D. A. Chu, J. V. Martins, R.-R. Li, C. Ichoku, R. C. Levy, R. G. Kleidman, T. F. Eck, E. Vermote, and B. N. Holben

diversity, MODIS has the unique ability to retrieve aerosol optical thickness with greater accuracy and to retrieve parameters characterizing aerosol size ( Tanré et al. 1996 ; Tanré et al. 1997 ). The results section of this paper shows that MODIS’s ability to separate aerosols by size can be used as a proxy for separating human-generated aerosol from natural sources, which aids substantially in estimating global human-induced aerosol forcing ( Kaufman et al. 2002 ). The first MODIS instrument was

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Takahiro Yabe, Robert Höller, Susumu Tohno, and Mikio Kasahara

) estimation of the aerosol radiative forcing at the surface, the top of the atmosphere, and in the atmosphere; 4) discussion of the columnar aerosol optical properties and the range of surface radiative forcing on the basis of the derived relationship between the aerosol optical thickness and the surface radiative forcing, together with comparison with radiative transfer calculations using model aerosols, and 5) comparison of the results of this study with observations of aerosol radiative forcing at

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Gottfried Hänel and Kurt Bullrich

particle numbers per cma at theearth's surface and at specific heights. Also compiledare the total optical thickness rD of the aerosol particles within the atmosphere, the percentage fractionsof rD coming from the different main layers, i.e.,lO0(rm/ro), lO0(r~m/r~) and lO0(rmn/rn), as wellas the percentage fraction of r~ coming from thelowest kilometer of the atmosphere, i.e.,to, for the standard case. For the inversion case, thepercentage fraction of r~ coming from the singlesublayer with the number K

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M. Griggs

APmL1979 M. GRIGGS 695Satellite Observations of Atmospheric Aerosols During the EOMET Cruise M. GRIGGS Science Applications, Inc., La Jolla, California 92038(Manuscript received 29 September 1978, in final form 18 December 1978) ABSTRACT Measurements of the atmospheric aerosol optical thickness were made during the 1977

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Toshihiko Takemura, Teruyuki Nakajima, Oleg Dubovik, Brent N. Holben, and Stefan Kinne

their direct and indirect effects on the climate system have recently been recognized as significant ( Jacobson 2000 ; Ackerman et al. 2000 ). These models were mainly compared with measurements of surface concentrations and several vertical profiles of each aerosol species. In recent years, on the other hand, global distributions of the aerosol optical thickness and Ångström exponent, 1 which are directly related to radiative transfer processes, have been retrieved from satellite- and ground

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J. L. Deuze, C. Devaux, M. Herman, R. Santer, and D. Tanre

- ~BSTRACT In July 1983, the summer transpo~ of $aharian aerosols across the Mediterranean Sea was observed. Thedust cloud was particularly dense and was clearly detected in A.V.H.R.R. and METEOSAT imageries. Optical~hlckne~ses and Angstr6m coet~cients have been derived from these pictures. Durin$ the same ~riod, groundbased observations--transmission, aureole and polarization measurements--were ~ormed at the Obr, e~valoiredc Haute Provence (southeast of France). Measumt aerosol optical thicknesses at

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Kazuhiko Masuda, Masayuki Sasaki, Tsutomu Takashima, and Hiroshi Ishida

1. Introduction Atmospheric aerosols play an important role in the earth radiation budget directly by scattering and absorbing solar and terrestrial radiation and indirectly by changing cloud properties. Accurate evaluation of the effects of the aerosols on the climate requires global information on aerosol properties such as optical thickness, size distribution, and refractive index. Ground-based measurements of the atmospheric aerosols by optical instruments such as sun photometers, aureole

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Alexander Smirnov, Brent N. Holben, Yoram J. Kaufman, Oleg Dubovik, Thomas F. Eck, Ilya Slutsker, Christophe Pietras, and Rangasayi N. Halthore

Aerosol Robotic Network (AERONET) in five island locations in the Pacific and Atlantic Oceans. The AERONET solar attenuation and sky brightness measurements are used to derive the spectral optical thickness and size distribution of the column ambient aerosol. In contrast to in situ measurements, AERONET remote measurements do not characterize the aerosol chemical composition, but measure the optical properties of the aerosol, unaffected by sampling and drying processes inherent in in situ methods. The

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K. M. Markowicz, P. J. Flatau, J. Remiszewska, M. Witek, E. A. Reid, J. S. Reid, A. Bucholtz, and B. Holben

columnar aerosol optical properties and aerosol size distribution. The annual cycle mostly is due to seasonal dust production and, therefore, aerosol optical thickness (AOT) is negatively correlated with the Ångström exponent. The maximum of AOT is observed during the summer and reaches 0.45 at 500 nm. Based on the Meteorological Satellite (Meteosat), observations in both the UV–visible and the infrared spectrum ( Deepshikha et al. 2005 ) derive the dust-absorbing efficiency over the north Indian Ocean

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