利用FY-3A/MERSI资料，结合MODIS C005算法的海上气溶胶模型，研究了中国渤海、黄海以及东海海域沙尘天气气溶胶光学厚度反演方法。通过MERSI反演的气溶胶光学厚度与MODIS C005气溶胶光学厚度产品（MOD04）对比，发现MERSI气溶胶光学厚度反演结果存在较大偏差。分析认为，这种偏差是由MODIS C005算法的海上气溶胶模型对MERSI气溶胶光学厚度反演不完全适用造成的。鉴于此，本文研究引进了一种沙尘气溶胶模型，并将其与MODIS C005算法的粗粒子气溶胶模型按照一定比例混合，形成了改进的气溶胶模型。利用改进气溶胶模型再次反演海上沙尘天气气溶胶光学厚度，反演结果与MOD04一致性较好，说明改进气溶胶模型能有效地提高MERSI定量反演沙尘气溶胶的能力。

The Aerosol Optical Depth (AOD) retrieval algorithm for sand-dust weather over ocean is investigated using FY-3A/Medium Resolution Spectral imager (MERSI) based on aerosol modes in the MODIS C005 over-ocean algorithm. The AOD (550 nm) retrieved from MERSI is evaluated with MODIS AOD product (MOD04). Results show a systematic bias in this algorithm. Further analyses reveal that this bias results from the MODIS-available aerosol modes. Therefore, a sand-dust aerosol mode is adopted to modify the MODIS aerosol modes by mixing them at an appropriate ratio. AOD is retrieved a second time based on the modified aerosol modes, and the corresponding results exhibit good consistency with MOD04, indicating that modified aerosol modes are more appropriate for the AOD retrieval from MERSI for sand-dust weather over ocean.