{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:40:24Z","timestamp":1760146824618,"version":"build-2065373602"},"reference-count":54,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2024,12,17]],"date-time":"2024-12-17T00:00:00Z","timestamp":1734393600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Jiangsu Funding Program for Excellent Postdoctoral Talent","award":["2024ZB632","B240201097","41974016","202006710169"],"award-info":[{"award-number":["2024ZB632","B240201097","41974016","202006710169"]}]},{"name":"the Fundamental Research Funds for the Central Universities","award":["2024ZB632","B240201097","41974016","202006710169"],"award-info":[{"award-number":["2024ZB632","B240201097","41974016","202006710169"]}]},{"name":"the National Natural Science Foundation of China","award":["2024ZB632","B240201097","41974016","202006710169"],"award-info":[{"award-number":["2024ZB632","B240201097","41974016","202006710169"]}]},{"name":"the State Scholarship Fund from Chinese Scholarship Council","award":["2024ZB632","B240201097","41974016","202006710169"],"award-info":[{"award-number":["2024ZB632","B240201097","41974016","202006710169"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>With the accumulation of synthetic aperture radar (SAR) altimetry data and advancements in retracking algorithms, the improved along-track spatial resolution and signal-to-noise ratio have significantly enhanced the availability and precision of sea surface height (SSH) measurements, particularly in challenging environments such as coastal areas, ocean currents, and polar regions. These improvements have refined the accuracy and reliability of mean sea surface (MSS) models, which in turn have enhanced the precision of mean dynamic topography (MDT) and geostrophic current models. However, in-depth research is required to quantify the specific contributions of SAR altimetry to these critical regions and their impacts on the MSS, MDT, and geostrophic currents. Given that DTU21MSS (Technical University of Denmark MSS 2021) incorporates a substantial amount of SAR altimetry data, this study utilized independent Sentinel-3A altimetric observations to evaluate the signal improvements of DTU21MSS compared with DTU15MSS, with a focus on its performance in polar, coastal, and current regions. In addition, a least-squares-based approach was employed to assess the impact of the improved MSS model on the deduced MDT and geostrophic current signals. The numerical results revealed that DTU21MSS achieved an accuracy improvement of ~8% within 20 km offshore compared with DTU15MSS. In the polar regions within 100 km offshore, DTU21MSS exhibited a maximum signal enhancement of ~0.1 m, with overall improvements of 10\u201320%. The DTU21MSS-derived MDT solution demonstrates better consistency with validation data, reducing the standard deviation of misfits from 0.058 m to 0.054 m. Signal enhancements of maximumly 0.1 m were observed in the polar regions and the Mediterranean\/Red Sea. Furthermore, improvements in the MSS and its error information could directly enhance the deduced MDT models, highlighting its foundational role in precise oceanographic modeling.<\/jats:p>","DOI":"10.3390\/rs16244714","type":"journal-article","created":{"date-parts":[[2024,12,17]],"date-time":"2024-12-17T10:54:02Z","timestamp":1734432842000},"page":"4714","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Evaluating the Signal Contribution of the DTU21MSS on Coastal Mean Dynamic Topography and Geostrophic Current Modeling: A Case Study in the African\u2013European Region"],"prefix":"10.3390","volume":"16","author":[{"given":"Hongkai","family":"Shi","sequence":"first","affiliation":[{"name":"School of Earth Sciences and Engineering, Hohai University, Nanjing 211100, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5262-1007","authenticated-orcid":false,"given":"Xiufeng","family":"He","sequence":"additional","affiliation":[{"name":"School of Earth Sciences and Engineering, Hohai University, Nanjing 211100, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6685-3415","authenticated-orcid":false,"given":"Ole Baltazar","family":"Andersen","sequence":"additional","affiliation":[{"name":"DTU Space, Technical University of Denmark, 2800 Lyngby, Denmark"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1808","DOI":"10.1175\/2008JTECHO568.1","article-title":"Calculating the Ocean\u2019s Mean Dynamic Topography from a Mean Sea Surface and a Geoid","volume":"25","author":"Bingham","year":"2008","journal-title":"J. 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