Applying the Dark Target Aerosol Algorithm to MERSI-Ⅱ:Retrieval and Validation of Aerosol Optical Depth over the Ocean  

作　　者：Xin PEI Leiku YANG Weiqian JI Shuang CHEN Xiaoqian CHENG Xiaofeng LU Hongtao WANG 

机构地区：[1]School of Surveying and Land Information Engineering,Henan Polytechnic University,Jiaozuo 454003,China

出　　处：《Advances in Atmospheric Sciences》2024年第12期2446-2463,共18页大气科学进展（英文版）

基　　金：supported in part by the National Natural Science Foundation of China(Grant Nos.42471424,41975036,and 42075132);the Fengyun Application Pioneering Project(Grant No.FY-APP024);the State Key Project of National Natural Science Foundation of China-Key projects of joint fund for regional innovation and development(Grant No.U22A20566);the Scientific and Technological Innovation Team of Universities in Henan Province(Grant No.22IRTSTHN008).

摘　　要：The Medium-Resolution Spectral Imager-Ⅱ(MERSI-Ⅱ)instrument aboard China’s Fengyun-3D satellite shares similarities with NASA’s Moderate Resolution Imaging Spectroradiometer(MODIS)sensor,enabling the retrieval of global aerosol optical depth(AOD).However,no officially released operational MERSI-Ⅱ aerosol products currently exist over the ocean.This study focuses on adapting the MODIS dark target(DT)ocean algorithm to the MERSI-Ⅱ sensor.A retrieval test is conducted on the 2019 MERSI-Ⅱ data over the global ocean,and the retrieved AODs are validated against ground-based measurements from the automatic Aerosol Robotic Network(AERONET)and the shipborne Maritime Aerosol Network(MAN).The operational MODIS DT aerosol products are also used for comparison purposes.The results show that MERSI-Ⅱ AOD granule retrievals are in good agreement with MODIS products,boasting high correlation coefficients(R)of up to 0.96 and consistent spatial distribution trends.Furthermore,the MERSI-Ⅱ retrievals perform well in comparison to AERONET and MAN measurements,with high R-values(>0.86).However,the low-value retrievals from MERSI-Ⅱ tend to be slightly overestimated compared to MODIS,despite both AODs displaying a positive bias.Notably,the monthly gridded AODs over the high latitudes of the northern and southern hemispheres suggest that MERSI-Ⅱ exhibits greater stability in space and time,effectively reducing unrealistically high-value noise in the MODIS products.These results illustrate that the MERSI-Ⅱ retrievals meet specific accuracy requirements by maintaining the algorithmic framework and most of the algorithmic assumptions,providing a crucial data supplement for aerosol studies and climate change.

关 键 词：aerosol optical depth MERSI-Ⅱ MODIS dark target 

分 类 号：P412[天文地球—大气科学及气象学] P732