Accuracy assessments of cloud droplet size retrievals from polarized reflectance measurements by the research scanning polarimeter

REMOTE SENSING OF ENVIRONMENT

卷:125

Article

Alexandrov, Mikhail D.^1,2  Cairns, Brian²  Emde, Claudia³  Ackerman, Andrew S.²  van Diedenhoven, Bastiaan^2,4 

[1] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA

[2] NASA, Goddard Inst Space Studies, New York, NY 10025 USA

[3] Univ Munich, Inst Meteorol, D-80333 Munich, Germany

[4] Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA

关键词: Electromagnetic scattering;    Polarization;    Mie theory;    Rainbow;    Optical particle characterization;    Remote sensing;   

DOI  :  10.1016/j.rse.2012.07.012

来源: Elsevier

【 摘 要 】

We present an algorithm for the retrieval of cloud droplet size distribution parameters (effective radius and variance) from the Research Scanning Polarimeter (RSP) measurements. The RSP is an airborne prototype for the Aerosol Polarimetery Sensor (APS), which was on-board of the NASA Glory satellite. This instrument measures both polarized and total reflectance in 9 spectral channels with central wavelengths ranging from 410 to 2260 nm. The cloud droplet size retrievals use the polarized reflectance in the scattering angle range between 135 degrees and 165 degrees, where they exhibit the sharply defined structure known as the rain- or cloud-bow. The shape of the rainbow is determined mainly by the single scattering properties of cloud particles. This significantly simplifies both forward modeling and inversions, while also substantially reducing uncertainties caused by the aerosol loading and possible presence of undetected clouds nearby. In this study we present the accuracy evaluation of our algorithm based on the results of sensitivity tests performed using realistic simulated cloud radiation fields. (c) 2012 Elsevier Inc. All rights reserved.

【 授权许可】

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