Evaluating the Signal Contribution of the DTU21MSS on Coastal Mean Dynamic Topography and Geostrophic Current Modeling: A Case Study in the African–European Region
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...
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2024-12-01
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| author | Hongkai Shi Xiufeng He Ole Baltazar Andersen |
| author_facet | Hongkai Shi Xiufeng He Ole Baltazar Andersen |
| author_sort | Hongkai Shi |
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| description | 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 10–20%. 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. |
| format | Article |
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| institution | DOAJ |
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| language | English |
| publishDate | 2024-12-01 |
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| series | Remote Sensing |
| spelling | doaj-art-bdfa225856b24d9fad7b7d034a9bfcaf2025-08-20T02:57:04ZengMDPI AGRemote Sensing2072-42922024-12-011624471410.3390/rs16244714Evaluating the Signal Contribution of the DTU21MSS on Coastal Mean Dynamic Topography and Geostrophic Current Modeling: A Case Study in the African–European RegionHongkai Shi0Xiufeng He1Ole Baltazar Andersen2School of Earth Sciences and Engineering, Hohai University, Nanjing 211100, ChinaSchool of Earth Sciences and Engineering, Hohai University, Nanjing 211100, ChinaDTU Space, Technical University of Denmark, 2800 Lyngby, DenmarkWith 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 10–20%. 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.https://www.mdpi.com/2072-4292/16/24/4714SAR altimetrymean sea surfacemean dynamic topographyvalidationdata fusion |
| spellingShingle | Hongkai Shi Xiufeng He Ole Baltazar Andersen Evaluating the Signal Contribution of the DTU21MSS on Coastal Mean Dynamic Topography and Geostrophic Current Modeling: A Case Study in the African–European Region Remote Sensing SAR altimetry mean sea surface mean dynamic topography validation data fusion |
| title | Evaluating the Signal Contribution of the DTU21MSS on Coastal Mean Dynamic Topography and Geostrophic Current Modeling: A Case Study in the African–European Region |
| title_full | Evaluating the Signal Contribution of the DTU21MSS on Coastal Mean Dynamic Topography and Geostrophic Current Modeling: A Case Study in the African–European Region |
| title_fullStr | Evaluating the Signal Contribution of the DTU21MSS on Coastal Mean Dynamic Topography and Geostrophic Current Modeling: A Case Study in the African–European Region |
| title_full_unstemmed | Evaluating the Signal Contribution of the DTU21MSS on Coastal Mean Dynamic Topography and Geostrophic Current Modeling: A Case Study in the African–European Region |
| title_short | Evaluating the Signal Contribution of the DTU21MSS on Coastal Mean Dynamic Topography and Geostrophic Current Modeling: A Case Study in the African–European Region |
| title_sort | evaluating the signal contribution of the dtu21mss on coastal mean dynamic topography and geostrophic current modeling a case study in the african european region |
| topic | SAR altimetry mean sea surface mean dynamic topography validation data fusion |
| url | https://www.mdpi.com/2072-4292/16/24/4714 |
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