摘要
海冰密集度是描述海冰特征的重要参数,准确获取海冰密集度对研究全球气候变化具有重要意义。针对北极夏季海冰密集度反演精度较低的问题,本文通过对微波辐射传输模型中的海冰发射率和初始海冰密集度进行优化估算,改善了微波辐射传输模型对夏季观测亮温的大气校正效果,从而优化被动微波海冰密集度的反演结果,本研究采用2019年6—9月的FY-3D/MWRI亮温数据,分别利用优化前和优化后的ASI2算法(ASI2和ASI2E),结合固定系点(FTP)与动态系点(DTP),分别获得了4套夏季北极海冰密集度数据(ASI2-FTP、ASI2-DTP、ASI2E-FTP、ASI2E-DTP),并利用14景MODIS影像对结果进行了精度验证。研究结果表明,本研究提出的优化方法可有效提高北极夏季海冰密集度的反演精度,其中该优化方法对基于固定系点的反演改进尤为明显,其优化后的均方根误差(root mean square error,ERMSE)由21.9%减小到15.43%,偏差(bias,|B_(bias)|)由-12.40%下降到-6.01%。4种反演方法中,基于动态系点的算法优化后(ASI2E-DTP)表现尤为明显,其E_(RMSE)和B_(bias)分别为14.33%和-4.53%。
Sea ice concentration is an important parameter to describe the characteristics of sea ice.It is of great significance to obtain accurate sea ice concentration for the study of global climate change.In this study,we improves the atmospheric correction effect of summer observed brightness temperature by optimizing the estimation of sea ice emissivity and initial sea ice concentration in the microwave radiative transfer model,thereby optimizing the retrieval results of sea ice concentration using passive microwaves.Based on the FY-3D/MWRI brightness temperature data from June to September 2019,four sets of Arctic sea ice concen-tration data(ASI2-FTP,ASI2-DTP,ASI2E-FTP,ASI2E-DTP)were obtained by using the original and en-hanced ASI2 algorithm(ASI2 and ASI2E)combined with fixed tie points and dynamic tie points(FTP and DTP).The results were evaluated by 14 MODIS images.The enhanced method can effectively improve the Arctic sea ice concentration retrieval in summer,which is particularly effective for the method based on fixed tie points.After enhancement,the root mean square error decreased from 21.9% to 15.43%,and the bias reduced from -12.40% to -6.01%.Among the four methods,the enhanced algorithm based on dynamic tie points(ASI2E-DTP)performs best,with a root mean square error of 14.33% and a bias of -4.53%.
作者
夏常伟
王鑫
叶玉芳
陈卓奇
XIA Changwei;WANG Xin;YE Yufang;CHEN Zhuoqi(School of Geospatial Engineering and Science,Sun Yat-sen University,Zhuhai 519082,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082,China;Key Laboratory of Comprehensive Observation of Polar Environment(Sun Yat-sen University),Ministry of Education,Zhuhai 519082,China;461175 Troops of PLA,Nanjing 210049,China)
出处
《极地研究》
北大核心
2025年第3期437-452,共16页
Chinese Journal of Polar Research
基金
广东省自然科学基金面上项目(2022A1515011545)
南方海洋科学与工程广东省实验室(珠海)创新团队建设项目(311021008)
风云卫星应用先行计划项目(FY-APP-2022.0201)资助。
作者简介
夏常伟,男,1997年生。硕士研究生,主要从事极地遥感、海冰密集度反演优化研究。E-mail:xiachw3@mail2.sysu.edu.cn;通信作者:叶玉芳,E-mail:yeyf8@mail.sysu.edu.cn。
