Retrieve sea surface salinity in estuaries by visible light and microwave remote sensing
Time：2022-03-10 19:13:00 Views：Author：hyyg
Recently, JIN Xuchen, a doctoral student in our laboratory, published a paper "Enhancing Spatial Resolution of Sea Surface Salinity in Estuarine Regions by Combining Microwave and Ocean Color Satellite Data" in the international journal IEEE Geoscience and Remote Sensing Letters, exploring the use of combined visible light and microwave remote sensing data reflection. The feasibility of modeling sea surface salinity in nearshore estuary areas. The corresponding author is researcher HE Xianqiang in our laboratory.
Observation of global sea surface salinity using spaceborne L-band microwave radiometers is one of the most important sources of ocean salinity data. However, due to limited spatial resolution (~ 40 km), it is difficult for spaceborne L-band microwave radiometers to accurately retrieve sea surface salinity in nearshore estuary areas and cannot meet application requirements.
This article uses the strong correlation between the CDOM absorption coefficient and seawater salinity in the estuary area, and combines the correspondence between the L-band sea surface emissivity and seawater salinity to propose a resolution enhancement algorithm to improve the sea surface salinity in the estuary area. degree of spatial resolution, and the model accuracy was verified in the Yangtze River estuary area and the Mississippi River estuary area. The results show that the model established in this article can improve the spatial resolution and accuracy of SMAP products. Compared with the 40-km resolution SMAP sea surface salinity product, the enhanced 4-km resolution sea surface salinity value more accurately retrieves the actual spatial distribution of sea surface salinity in the estuary area (in the Yangtze River estuary area: 4 The RMSE for km and 40 km sea surface salinity is 1.55 psu and 2.58 psu respectively; at the mouth of the Mississippi: the RMSE for 4 km and 40 km sea surface salinity is 0.39 psu and 1.39 psu respectively)
Figure 1. (Left) Comparison between the Yangtze River Estuary regional model inversion results, 40-km resolution SMAP salinity data and measured values; (right) Mississippi Estuary regional model inversion results, 40-km resolution SMAP salinity data and Comparison between measured values.
Xuchen Jin, Xianqiang He, Yan Bai, Difeng Wang, Qiankun Zhu, Fang Gong and Delu Pan, "Enhancing Spatial Resolution of Sea Surface Salinity in Estuarine Regions by Combining Microwave and Ocean Color Satellite Data," in IEEE Geoscience and Remote Sensing Letters, doi: 10.1109/LGRS.2021.3126399
