%0 Journal Article
%T Validation of Two MODIS Aerosols Algorithms with SKYNET and Prospects for Future Climate Satellites Such as the GCOM-C/SGLI
%A Jules R. Dim
%A Tamio Takamura
%A Akiko Higurashi
%A Pradeep Kathri
%A Nobuyuki Kikuchi
%A Takahashi Y. Nakajima
%J Advances in Meteorology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/508064
%X Potential improvements of aerosols algorithms for future climate-oriented satellites such as the coming Global Change Observation Mission Climate/Second generation Global Imager (GCOM-C/SGLI) are discussed based on a validation study of three years¡¯ (2008¨C2010) daily aerosols properties, that is, the aerosol optical thickness (AOT) and the £¿ngstr£¿m exponent (AE) retrieved from two MODIS algorithms. The ground-truth data used for this validation study are aerosols measurements from 3 SKYNET ground sites. The results obtained show a good agreement between the ground-truth data AOT and that of one of the satellites¡¯ algorithms, then a systematic overestimation (around 0.2) by the other satellites¡¯ algorithm. The examination of the AE shows a clear underestimation (by around 0.2¨C0.3) by both satellites¡¯ algorithms. The uncertainties explaining these ground-satellites¡¯ algorithms discrepancies are examined: the cloud contamination affects differently the aerosols properties (AOT and AE) of both satellites¡¯ algorithms due to the retrieval scale differences between these algorithms. The deviation of the real part of the refractive index values assumed by the satellites¡¯ algorithms from that of the ground tends to decrease the accuracy of the AOT of both satellites¡¯ algorithms. The asymmetry factor (AF) of the ground tends to increase the AE ground-satellites discrepancies as well. 1. Introduction The determination of the optical properties of aerosols and their size distribution around the globe has been a significant contemporary research effort of late [1]. Some of the major factors that have enabled this progress are the better spectral and spatial capacities of satellites and ground-based radiometers, the improvement of the aerosol signal filtering methods, the better knowledge of the aerosols particles¡¯ shapes, and so forth. The qualitative and quantitative importance of the data collected through the continuous monitoring of aerosols and their daily global coverage, by various satellites, has permitted a better characterization of the role of the aerosols in the climate dynamics and the understanding of their temporal and local variation. The most common aerosols optical and physical properties used for this characterization are the AOT, the AE, the particle size distribution, the single scattering albedo (SSA), the aerosol phase function, the asymmetry factor (AF), the refractive index (RI), and so forth. To obtain these aerosols characteristics from satellites¡¯ observations, a detailed model of the aerosols properties is required [2]. The increasing
%U http://www.hindawi.com/journals/amete/2013/508064/