Improved estimation of aerosol optical depth from MODIS imagery over land surfaces
Improved estimation of aerosol optical depth from MODIS imagery over land surfaces
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DOI：
10.1016/j.rse.2006.05.016
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发表时间：
2006-10
影响因子：
13.5
通讯作者：
S. Liang;B. Zhong;H. Fang
中科院分区：
文献类型：
--
作者：
S. Liang;B. Zhong;H. Fang
气溶胶负荷的估算对全球气候变化研究具有重要意义。目前的陆地上的中分辨率成像光谱仪（MODIS）气溶胶估计算法是基于“暗物体”方法，这种方法只适用于植被密集的（“暗”）表面。在这项研究中，我们开发了一种新的气溶胶估计算法，该算法使用来自陆地表面，特别是“明亮”表面的一系列MODIS图像的时间特征。通过气溶胶机器人网络（AERONET）的测量验证了估计的气溶胶光学深度。实例研究表明，该算法可以较好地从7个站点的冬季MODIS图像中检索气溶胶光学深度：美国大华盛顿地区的4个站点；中国北京市；Banizoumbou，尼日尔，非洲；和加拿大的布拉茨湖。然而，陆地上的MODIS气溶胶估计算法（MOD04）在这些非植被表面上表现不佳。这种新算法有可能用于具有类似时间分辨率的其他卫星图像。
Estimation of aerosol loadings is of great importance to the studies on global climate changes. The current Moderate-Resolution Imaging Spectroradiometer (MODIS) aerosol estimation algorithm over land is based on the “dark-object” approach, which works only over densely vegetated (“dark”) surfaces. In this study, we develop a new aerosol estimation algorithm that uses the temporal signatures from a sequence of MODIS imagery over land surfaces, particularly “bright” surfaces. The estimated aerosol optical depth is validated by Aerosol Robotic Network (AERONET) measurements. Case studies indicate that this algorithm can retrieve aerosol optical depths reasonably well from the winter MODIS imagery at seven sites: four sites in the greater Washington, DC area, USA; Beijing City, China; Banizoumbou, Niger, Africa; and Bratts Lake, Canada. The MODIS aerosol estimation algorithm over land (MOD04), however, does not perform well over these non-vegetated surfaces. This new algorithm has the potential to be used for other satellite images that have similar temporal resolutions.