Comparative Analysis between Sea Surface Salinity Derived from SMOS Satellite Retrievals and in Situ Measurements
Validating Sea Surface Salinity (SSS) data has become a key component of the Soil Moisture Ocean Salinity (SMOS) satellite mission. In this study, the gridded SMOS SSS products are compared with in situ SSS data from analyzed products, a ship-based thermosalinograph and a tropical moored buoy array....
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-10-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/14/21/5465 |
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| author | Haodi Wang Kaifeng Han Senliang Bao Wen Chen Kaijun Ren |
| author_facet | Haodi Wang Kaifeng Han Senliang Bao Wen Chen Kaijun Ren |
| author_sort | Haodi Wang |
| collection | DOAJ |
| description | Validating Sea Surface Salinity (SSS) data has become a key component of the Soil Moisture Ocean Salinity (SMOS) satellite mission. In this study, the gridded SMOS SSS products are compared with in situ SSS data from analyzed products, a ship-based thermosalinograph and a tropical moored buoy array. The comparison was conducted at different spatial and temporal scales. A regional comparison in the Baltic Sea shows that SMOS slightly underestimates the mean SSS values. The influence of river discharge overrides the temperature in the Baltic Sea, bringing larger biases near river mouths in warm seasons. The global comparison with two Optimal Interpolated (OI) gridded in situ products shows consistent large-scale structures. Excluding regions with large SSS biases, the mean ΔSSS between monthly gridded SMOS data and OI in situ data is −0.01 PSU in most open sea areas between 60°S and 60°N, with a mean Root Mean Square Deviation (RMSD) of 0.2 PSU and a mean correlation coefficient of 0.50. An interannual tendency of mean ΔSSS shifting from negative to positive between satellite SSS and in situ SSS has been identified in tropical to mid-latitude seas, especially across the tropical eastern Pacific Ocean. A comparison with collocated buoy salinity shows that on weekly and interannual scales, the SMOS Level 3 (L3) product well captures the SSS variations at the locations of tropical moored buoy arrays and shows similar performance with in situ gridded products. Excluding suspicious buoys, the synergetic analysis of SMOS, SMAP and gridded in situ products is capable of identifying the erroneous data, implying that satellite SSS has the potential to act as a real-time 27 Quality Control (QC) for buoy data. |
| first_indexed | 2024-03-09T18:41:43Z |
| format | Article |
| id | doaj.art-109ba9e874f34a7c86297f18636804c5 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-09T18:41:43Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-109ba9e874f34a7c86297f18636804c52023-11-24T06:39:28ZengMDPI AGRemote Sensing2072-42922022-10-011421546510.3390/rs14215465Comparative Analysis between Sea Surface Salinity Derived from SMOS Satellite Retrievals and in Situ MeasurementsHaodi Wang0Kaifeng Han1Senliang Bao2Wen Chen3Kaijun Ren4Institute of Numerical Meteorology and Oceanography, College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, ChinaInstitute of Numerical Meteorology and Oceanography, College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, ChinaInstitute of Numerical Meteorology and Oceanography, College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, ChinaInstitute of Numerical Meteorology and Oceanography, College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, ChinaInstitute of Numerical Meteorology and Oceanography, College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, ChinaValidating Sea Surface Salinity (SSS) data has become a key component of the Soil Moisture Ocean Salinity (SMOS) satellite mission. In this study, the gridded SMOS SSS products are compared with in situ SSS data from analyzed products, a ship-based thermosalinograph and a tropical moored buoy array. The comparison was conducted at different spatial and temporal scales. A regional comparison in the Baltic Sea shows that SMOS slightly underestimates the mean SSS values. The influence of river discharge overrides the temperature in the Baltic Sea, bringing larger biases near river mouths in warm seasons. The global comparison with two Optimal Interpolated (OI) gridded in situ products shows consistent large-scale structures. Excluding regions with large SSS biases, the mean ΔSSS between monthly gridded SMOS data and OI in situ data is −0.01 PSU in most open sea areas between 60°S and 60°N, with a mean Root Mean Square Deviation (RMSD) of 0.2 PSU and a mean correlation coefficient of 0.50. An interannual tendency of mean ΔSSS shifting from negative to positive between satellite SSS and in situ SSS has been identified in tropical to mid-latitude seas, especially across the tropical eastern Pacific Ocean. A comparison with collocated buoy salinity shows that on weekly and interannual scales, the SMOS Level 3 (L3) product well captures the SSS variations at the locations of tropical moored buoy arrays and shows similar performance with in situ gridded products. Excluding suspicious buoys, the synergetic analysis of SMOS, SMAP and gridded in situ products is capable of identifying the erroneous data, implying that satellite SSS has the potential to act as a real-time 27 Quality Control (QC) for buoy data.https://www.mdpi.com/2072-4292/14/21/5465sea surface salinitySMOSmoored buoyin situ measurements |
| spellingShingle | Haodi Wang Kaifeng Han Senliang Bao Wen Chen Kaijun Ren Comparative Analysis between Sea Surface Salinity Derived from SMOS Satellite Retrievals and in Situ Measurements Remote Sensing sea surface salinity SMOS moored buoy in situ measurements |
| title | Comparative Analysis between Sea Surface Salinity Derived from SMOS Satellite Retrievals and in Situ Measurements |
| title_full | Comparative Analysis between Sea Surface Salinity Derived from SMOS Satellite Retrievals and in Situ Measurements |
| title_fullStr | Comparative Analysis between Sea Surface Salinity Derived from SMOS Satellite Retrievals and in Situ Measurements |
| title_full_unstemmed | Comparative Analysis between Sea Surface Salinity Derived from SMOS Satellite Retrievals and in Situ Measurements |
| title_short | Comparative Analysis between Sea Surface Salinity Derived from SMOS Satellite Retrievals and in Situ Measurements |
| title_sort | comparative analysis between sea surface salinity derived from smos satellite retrievals and in situ measurements |
| topic | sea surface salinity SMOS moored buoy in situ measurements |
| url | https://www.mdpi.com/2072-4292/14/21/5465 |
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