Significant overestimation of global aerosol optical thickness by MODIS over land
Significant overestimation of global aerosol optical thickness by MODIS over land
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DOI：
10.1007/s11434-006-2157-2
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发表时间：
2006-12
影响因子：
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通讯作者：
X. Xia
中科院分区：
文献类型：
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作者：
X. Xia
利用中分辨率成像光谱仪（MODIS）获得的全球陆地气溶胶光学厚度（AOT）数据与气溶胶机器人网络（AERONET）反演的AOT数据进行了对比分析。在一般情况下，MODIS高估AOT除了在非洲和东亚的一些AERONET网站。在470 nm和660 nm处，MODIS/AOTs平均比AERONET/AOTs分别大0.041和0.090。660 nm处的AOT偏差与2130 nm处的表面反射率显著相关。这两个事实表明，表面反射率的低估是在660 nm的这种偏差的主要原因。强烈建议使用470 nm的MODIS/AOT，因为它比660 nm的AOT可靠得多。
Global aerosol optical thickness (AOT) data over land obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) are evaluated through comparisons with AOT data retrieved by Aerosol Robotic Network (AERONET). In general, MODIS overestimates AOT except at a few AERONET sites in Africa and eastern Asia. MODIS/AOTs are, on average, larger than AERONET/AOTs by 0.041 and 0.090 at 470 nm and 660 nm, respectively. The AOT bias at 660 nm is significantly correlated to the surface reflectance at 2130 nm. Both facts suggest that the underestimation of the surface reflectance is the principal reason for this bias at 660 nm. To use the MODIS/AOT at 470 nm is strongly recommended because it is much more reliable than the AOT at 660 nm.