Recently, Researcher He Xianqiang from our laboratory and his collaborators published a paper entitled Geostationary ocean color satellite observations reveal the fine structure of mesoscale eddy dynamics in the top-tier remote sensing journal Remote Sensing of Environment. The first author is Postdoctoral Researcher Ding Xiaosong from the East China Sea Laboratory, and Researcher He Xianqiang serves as the corresponding author. Co-researchers include Researcher Bai Yan, Researcher Ma Wentao, Researcher Wang Difeng, Senior Engineer Gong Fang, Associate Researcher Li Teng and Dr. Ye Feng from our institute, as well as Associate Professor Yu Shujie from Jimei University, Associate Professor Hu Qiwei from Jiangsu Ocean University and Dr. Li Jiajia from Yunnan University.
Mesoscale eddies carry around 90% of global ocean kinetic energy, exerting crucial impacts on the transport of marine substances and energy, and directly regulate the distribution of oceanic heat, salinity, biogenic elements and other key marine parameters. Satellite altimeters are the mainstream means to monitor global marine mesoscale eddies. However, traditional satellite altimeter remote sensing products suffer from low spatiotemporal resolution, with a spatial resolution of approximately 25 kilometers and a temporal resolution of about one observation per day, which cannot satisfy the demand for refined dynamic monitoring of flow fields within mesoscale eddies.
Currently, geostationary ocean color satellite sensors (e.g. GOCI, GOCI-II) can provide all-day hourly observational data with meter-level spatial resolution (500 m for GOCI and 250 m for GOCI-II), which supplies valuable observational data for refined monitoring of sea surface flow field structures of mesoscale eddies.
Combining the Farnebäck optical flow algorithm and Diffeomorphic-PIV technology, the research team established a refined sea surface flow field remote sensing retrieval algorithm for mesoscale eddies based on geostationary ocean color satellite observations. In mesoscale eddy areas, sea surface flow fields retrieved by GOCI geostationary ocean color satellites are in good agreement with geostrophic flow fields derived from traditional satellite altimeters. Featuring higher spatiotemporal resolution (higher than 500 meters with hourly updates), the new method can effectively capture the fine dynamic and ecological structures of eddies.
The hourly refined sea surface flow field data obtained from geostationary ocean color satellites can accurately pinpoint the center and edge of eddies, effectively making up for the deficiency of traditional altimeter flow field products that fail to precisely locate eddy cores and boundaries due to low spatial resolution. In addition, the hourly flow field data can be further used to calculate the lateral transport flux of phytoplankton in the near-surface water of eddies and monitor the hourly variation of Eddy Kinetic Energy (EKE) of mesoscale eddies. The refined flow field information derived from geostationary ocean color satellites helps deepen the understanding of marine mesoscale eddy dynamics and material transport mechanisms.
This research is jointly supported by the National Key R&D Program of China, the National Natural Science Foundation of China, Zhejiang Provincial Pioneer Major Science and Technology Research Program and other research projects.
Fig.1 Comparison between sea surface flow fields extracted by GOCI and AVISO geostrophic currents. (a) GOCI-derived flow field; (b) AVISO-derived flow field. Arrows represent flow direction, and background color indicates flow velocity magnitude. (c) & (d) Comparison of flow velocity in U and V components.
Fig.2 Comparison of three sea surface flow field products of typical mesoscale eddies in the Sea of Japan. (a) OSCAR flow field product; (b) AVISO flow field product; (c) Flow field retrieved by GOCI.
Fig.3 Spatiotemporal variations of Eddy Kinetic Energy (EKE) (upper), chlorophyll-a flux (middle) and chlorophyll-a concentration (lower). Left: daily mean results; middle: hourly spatial distribution; right: hourly variation along designated transects. Transect I is 50 km away from the Y-axis, and Transect II is 80 km away from the X-axis.
Paper Citation
Ding, X., He, X.*, Bai, Y., Ma, W., Li, J., Ye, F., Yu, S., Hu, Q., Gong, F., Wang, D., & Li, T. (2025). Geostationary ocean color satellite observations reveal the fine structure of mesoscale eddy dynamics. Remote Sensing of Environment, 320: 114652. DOI: 10.1016/j.rse.2025.114652.
