Intercomparison between multi-angle imaging spectroradiometer and sunphotometer aerosol optical thickness in dust source regions over China: implications for satellite aerosol retrievals and radiative forcing calculations
Intercomparison between multi-angle imaging spectroradiometer and sunphotometer aerosol optical thickness in dust source regions over China: implications for satellite aerosol retrievals and radiative forcing calculations
复制标题
DOI：
10.1111/j.1600-0889.2004.00120.x
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Jun Wang
中科院分区：
文献类型：
--
作者：
Jun Wang
对2000年3 - 11月敦煌（40.09°N, 94.41°E）多角度成像光谱辐射计（MISR）气溶胶光学厚度（AOT）产品（τ MISR）与太阳光度计AOT （τ SP）进行了比较。这项研究是独一无二的，因为地面上的AOT测量在尘源区域或附近通常是不可用的。τ MISR和τ SP高度相关，线性相关系数(R)在0.85至0.95之间，这取决于用于评估MISR检索的不同比较标准。除了一个例外，在尘埃锋通过期间τ MISR与τ SP相比显示出很大的差异（>0.3），所有其他并配的τ SP/τ MISR对与R > 0.9高度相关，在检索条件有利时，均方根误差为0.06。总体而言，τ MISR系统地高估了τ SP 0.05，但它们都在预测的不确定性范围内（τ SP的0.05或20%，以较大者为准）。由于AOT的日变化，MISR立交桥期间报告的日平均τ SP值与τ MISR之间的差异约为0.09。我们讨论了这些结果对卫星气溶胶反演和辐射强迫研究的意义。
The multi-angle imaging spectroradiometer (MISR) aerosol optical thickness (AOT) product (τ MISR) was compared with sunphotometer AOT (τ SP) at Dunhuang (40.09◦N, 94.41◦E), located near the Takalamakan and Gobi dust source regions in China, during March–November 2000. This study is unique because AOT measurements from the ground are not routinely available at or near dust source regions. The τ MISR and τ SP are highly correlated, with linear correlation coefficients (R) ranging from 0.85 to 0.95 depending on the different comparison criteria used to assess the MISR retrievals. With one exception where τ MISR shows large differences (>0.3) when compared with τ SP during the passage of a dust front, all other collocated τ SP/τ MISR pairs are highly correlated with R > 0.9 and with root-mean-square error of 0.06 when retrieval conditions are favourable. Overall, τ MISR systemically over-estimate τ SP by 0.05, but they all fall within the predicted uncertainties (0.05 or 20% of τ SP, whichever is larger). Due to diurnal change of AOT, the difference between daily averaged τ SP values and τ MISR reported during MISR overpass time is about 0.09. We discuss the implications of these results for satellite aerosol retrievals and radiative forcing studies.