| 一种温度相关的HY-2A散射计地球物理模型函数 |
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| 引用本文： | 陈克海,解学通,张金兰,郑艳.一种温度相关的HY-2A散射计地球物理模型函数[J].热带海洋学报,2022,41(2):90-102. |
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| 作者姓名： | 陈克海 解学通 张金兰 郑艳 |
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| 作者单位： | 1. 广东工贸职业技术学院, 测绘遥感信息学院, 广东 广州 5105102. 广州大学, 地理科学与遥感学院, 广东 广州 510006 |
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| 基金项目： | 国家自然科学基金(41876204);国家自然科学基金(41476152);广东省科技创新战略专项资金(pdjh2020b0929);广东工贸职业技术学院科研课题(2021-ZK-10) |
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| 摘 要： | 利用散射计测量海面后向散射系数, 并通过地球物理模型函数(geophysical model function, GMF)反演得到海面风场。目前散射计风场反演所采用的GMF一般只考虑雷达极化方式、雷达入射角、风速和相对风向对海面后向散射系数的影响, 而相关研究表明海表温度(sea surface temperature, SST)对Ku波段散射计风场反演具有不可忽略的影响。文章利用海洋二号A卫星散射计(Haiyang-2A Scatterometer, HY2A-SCAT)后向散射系数观测值、欧洲中期天气预报中心(European Center for Medium-Range Weather Forecasts, ECMWF )再分析风矢量和SST数据, 采用人工神经网络方法, 建立起一种SST相关的GMF (TNGMF)。对TNGMF进行分析后发现, 海面后向散射系数随着SST的增加而增加, 并且其增加幅度与雷达极化方式、风速有关。为了对比, 文章使用相同数据集和相同方法建立了不包含SST的GMF (NGMF), 将美国国家航天航空局散射计-2 (National Aeronautics and Space Administration Scatterometer-2, NSCAT2) GMF、TNGMF和NGMF分别用于HY2A-SCAT风场反演实验。试验结果表明, 采用NSCAT2 GMF、NGMF反演得到的风速在低温时系统性偏小, 在高温时系统性偏大; 而TNGMF可较好地纠正SST对风速偏差均值的影响, 从而提高反演风场质量。
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| 关 键 词： | HY-2A散射计 海表温度 风场反演 地球物理模型函数 |
| 收稿时间： | 2021-03-30 |
| 修稿时间： | 2021-06-05 |
An SST dependent geophysical model function for HY-2A scatterometer |
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| CHEN Kehai,XIE Xuetong,ZHANG Jinlan,ZHENG Yan.An SST dependent geophysical model function for HY-2A scatterometer[J].Journal of Tropical Oceanography,2022,41(2):90-102. |
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| Authors: | CHEN Kehai XIE Xuetong ZHANG Jinlan ZHENG Yan |
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| Institution: | 1. School of Mapping and Remote Sensing, Guangdong Polytechnic of Industry and Commerce, Guangzhou 510510, China2. School of Geography and Remote Sensing, Guangzhou University, Guangzhou 510006, China |
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| Abstract: | Scatterometers measure the normalized radar cross-section (NRCS) from the sea surface, which is then used to retrieve the wind vector over the sea surface using the geophysical model function (GMF). The GMFs adopted by the wind retrieval of scatterometers generally consider the influence of the radar polarization, radar incident angle, wind speed, and relative direction, but research showed that sea-surface temperature (SST) has a non negligible impact on the wind retrieval of scatterometers in the Ku band. In this study, we use Haiyang-2A scatterometer (HY2A-SCAT) L2A data, European Center for Medium-Range Weather Forecasts (ECMWF) reanalysis wind and SST data to build an SST-dependent GMF (TNGMF) using the artificial neural network. Using the TNGMF, we find that the NRCS increases with SST, and its range affected by SST is related to radar polarization and wind speed. In contrast, we use the same dataset and the same method to build another GMF without considering SST (NGMF); we then use NSCAT2 (NASA scatterometer-2) GMF, NGMF and TNGMF in the wind retrieval of HY2A-SCAT and find that NSCAT2 and NGMF wind speeds are systemically lower at low SST, and systemically higher at high SST. However, the TNGMF can well adjust the wind speed deviation affected by SST to improve the quality of retrieved wind. |
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| Keywords: | HY-2A scatterometer sea-surface temperature wind retrieval geophysical model function |
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