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Sungwook Hong and Inchul Shin

is the small-scale roughness, is the wavelength, and θ is the view angle. 3. Data and methods a. Small-scale roughness retrieval In general, calculation of specular reflectivity at a given frequency and incidence angle using the Fresnel equation requires a priori information on the surface. In many cases, the dielectric property of the surface is not known because of the variety, heterogeneity, and complexity of the surface component and physical state. To use the observed polarization

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Allison McComiskey and Richard A. Ferrare

that it is a primarily light-scattering aerosol. Despite the recognition that there would be an attendant effect from absorbing aerosol, no estimate could be made for lack of knowledge of their mass, optical properties, and distribution. While containing substantial uncertainty, these estimates of cooling by aerosol are of a magnitude that could offset the warming caused by increases in greenhouse gases over the industrial period. The tenet of the ARM Program at the outset was to improve the

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S. A. Young, C. M. R. Platt, R. T. Austin, and G. R. Patterson

Introduction The effects of clouds on the earth’s radiation budget are still little known and understood only approximately. For example, Le Treut et al. (1994) show that two different cloud parameterizations for midlevel clouds give cloud solar and infrared radiative forcings that both differ by up to 20 W m −2 in some regions. In a survey of GCMs, Browning (1994) listed cloud cover and optical properties as among the highest stated priorities for GCM development. Basically, cloud

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Joanna Slawinska, Wojciech W. Grabowski, Hanna Pawlowska, and Andrzej A. Wyszogrodzki

concentration to the extremely inhomogeneous mixing leads to a decrease of PDF for small τ s and an increase for τ > 10. However, changes in the PDFs between PRISTINE and POLLUTED cases are smaller than in G06 , consistent with only the first indirect effect considered here (i.e., changes of r e alone), whereas both the first and the second indirect effects were considered in G06 (i.e., changes in both r e and LWP). To document the impact of various mixing scenarios on mean optical properties of

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J. Li and Qilong Min

1. Introduction In recent years, atmospheric aerosols have been considered important for climate change because their direct forcing and indirect forcing are appreciable to alter the radiative balance. Among all aerosols, sulfate aerosols have been paid most attention, since sulfate aerosols over land are mostly an anthropogenic product and since the optical properties and size distributions of sulfate aerosols could be reasonably well known. Most of studies on atmospheric aerosol are focused

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Alberto Adriani, Francesco Cairo, Maurizio Viterbini, Stefania Mandolini, Lucio Pulvirenti, and Guido Di Donfrancesco

of a better understanding of PSC properties, during the last few years joint lidar and optical particle counters (OPC) measurements were carried out in Antarctica ( Deshler et al. 1991 ; Adriani et al. 1992 ). While the OPC was able to assess particle concentrations and sizing, the lidar could give a contemporary measurement of the aerosol volume cross section for backscattered signals and information on the depolarizing properties of the particles, hence their thermodynamical phase. In the

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Graeme L. Stephens and John C. Scott

148 JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY VOLUME2A High Speed Spectra!!y Scanning Radiometer (SPERAD) for Airborne Measurements of Cloud Optical Properties GRAEME L. STEPHENS AND JOHN C. SCOTTCSIRO Division of Atmospheric Research, Aspendale, Victoria, Australia. 3195(Manuscript received 28 December 1983~ in final form 7 September 1984) The overall design of a radiometer and data

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Philip B. Russell and Gerald W. Grams

SF. PTEm~l;.~1975 PHILIP B. RUSSELl. AND GERAI. D W. GRAMS 1037Application of Soil Dust Optical Properties in Analytical Models of Climate Change PHILIP B. RUSSELL Stanford Research Institute, Menlo Park, Cahf. 94025 GER^Ln W. GRA~4SNational Cenler for A tmospherlc Research? J~oulder, Colo. 80303(Manuscript received 19 August 1974, in revised form 3 February 1975

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Y. Knyazikhin, R. B. Myneni, A. Marshak, W. J. Wiscombe, M. L. Larsen, and J. V. Martonchik

) How can information on small-scale drop variability be incorporated into the radiative transfer equation? 3) What is the effect of ignoring small-scale variability on cloud optical properties? The objective of this paper is to address these questions. This paper is organized as follows. In sections 2 and 3 , aircraft data on liquid water drop sizes measured by the Forward Scattering Spectrometer Probe (FSSP) during the First International Satellite Cloud Climatology Project (ISCCP) Regional

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Mikhail D. Alexandrov, Alexander Marshak, Brian Cairns, Andrew A. Lacis, and Barbara E. Carlson

reported method ( Alexandrov et al. 2002b ). The retrieval products include daily time series of the aerosol optical thickness in all spectral channels and at a reference wavelength of 550 nm, column mean aerosol particle size, and NO 2 and ozone column amounts. As part of the data processing, a spectrally self-consistent instrument calibration is determined from the data. In this paper we describe scaling properties of the aerosol optical thickness (AOT) at the 550-nm wavelength. This (derived

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