{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T23:17:41Z","timestamp":1769728661944,"version":"3.49.0"},"reference-count":29,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2024,2,23]],"date-time":"2024-02-23T00:00:00Z","timestamp":1708646400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City","award":["2021CXLH0019"],"award-info":[{"award-number":["2021CXLH0019"]}]},{"name":"Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City","award":["2021-YB-03"],"award-info":[{"award-number":["2021-YB-03"]}]},{"name":"Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City","award":["42006008"],"award-info":[{"award-number":["42006008"]}]},{"name":"Key Laboratory of Marine Science and Numerical Modeling, Ministry of Natural Resources","award":["2021CXLH0019"],"award-info":[{"award-number":["2021CXLH0019"]}]},{"name":"Key Laboratory of Marine Science and Numerical Modeling, Ministry of Natural Resources","award":["2021-YB-03"],"award-info":[{"award-number":["2021-YB-03"]}]},{"name":"Key Laboratory of Marine Science and Numerical Modeling, Ministry of Natural Resources","award":["42006008"],"award-info":[{"award-number":["42006008"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2021CXLH0019"],"award-info":[{"award-number":["2021CXLH0019"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2021-YB-03"],"award-info":[{"award-number":["2021-YB-03"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["42006008"],"award-info":[{"award-number":["42006008"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This paper presents an innovative approach to enhance the assimilation of high-resolution simulated observations, specifically targeting Surface Water Ocean Topography (SWOT) Ka-band Radar Interferometer Sea Surface Height (SSH) products, within the Regional Ocean Modeling System (ROMS). Responding to the demand for improved assimilation techniques, we developed a multi-scale Four-Dimensional Variational Data Assimilation (4DVAR) system, building upon validated fine-scale correction capabilities from prior studies. The multi-scale strategy was extended to the ROMS-4DVAR system, providing a comprehensive solution for assimilating high-resolution observations. Leveraging the Observing System Simulation Experiment (OSSE) framework, we conducted a twin experiment comprising a nature run and a free run case. Subsequently, synthetic SWOT SSH measurements were decomposed, considering the model configuration resolution. These components, derived from dense SSH observations, were integrated into a two-step 4DVAR assimilation scheme. The first cycle targets large-scale features for model field correction, and the updated analysis serves as the background for the second assimilation step, addressing fine-scale observation components. Comparisons with the primitive ROMS-4DVAR using a single-scale scheme highlight the superiority of the multi-scale strategy in reducing gaps between the model and the SSH observations. The Root Mean Squared Error (RMSE) is halved, and the Mean Absolute Percentage Error (MAPE) decreases from 2.237% to 0.93%. The two-step assimilation procedure ensures comprehensive multi-scale updates in the SSH field simulation, enhancing fine-scale features in the analysis fields. The quantification of three-dimensional-model dynamic fields further validates the efficiency and superiority of the multi-scale 4DVAR approach, offering a robust methodology for assimilating high-resolution observations within the ROMS.<\/jats:p>","DOI":"10.3390\/rs16050778","type":"journal-article","created":{"date-parts":[[2024,2,23]],"date-time":"2024-02-23T06:07:39Z","timestamp":1708668459000},"page":"778","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Enhancing the Assimilation of SWOT Simulated Observations Using a Multi-Scale 4DVAR Method in Regional Ocean Modeling System"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1916-012X","authenticated-orcid":false,"given":"Chaojie","family":"Zhou","sequence":"first","affiliation":[{"name":"Hainan Institute of Zhejiang University, Sanya 572024, China"},{"name":"Key Laboratory of Marine Science and Numerical Modeling, Ministry of Natural Resources, Qingdao 266061, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0456-9002","authenticated-orcid":false,"given":"Wei","family":"Cui","sequence":"additional","affiliation":[{"name":"First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China"}]},{"given":"Ruili","family":"Sun","sequence":"additional","affiliation":[{"name":"Hainan Institute of Zhejiang University, Sanya 572024, China"}]},{"given":"Ying","family":"Huang","sequence":"additional","affiliation":[{"name":"Hainan Institute of Zhejiang University, Sanya 572024, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4265-5964","authenticated-orcid":false,"given":"Zhanpeng","family":"Zhuang","sequence":"additional","affiliation":[{"name":"First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China"}]}],"member":"1968","published-online":{"date-parts":[[2024,2,23]]},"reference":[{"key":"ref_1","first-page":"20160117","article-title":"Submesoscale currents in the ocean","volume":"472","author":"McWilliams","year":"2016","journal-title":"Proc. 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