Journal of the Korean earth science society (한국지구과학회지)

The Korean Earth Science Society (한국지구과학회)
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Accuracy and Error Characteristics of SMOS Sea Surface Salinity in the Seas around Korea

  • Park, Kyung-Ae (Department of Earth Science Education, Seoul National University) ;
  • Park, Jae-Jin (Department of Science Education, Seoul National University)
  • Received : 2020.08.08
  • Accepted : 2020.08.20
  • Published : 2020.08.31
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Abstract

The accuracy of satellite-observed sea surface salinity (SSS) was evaluated in comparison with in-situ salinity measurements from ARGO floats and buoys in the seas around the Korean Peninsula, the northwest Pacific, and the global ocean. Differences in satellite SSS and in-situ measurements (SSS errors) indicated characteristic dependences on geolocation, sea surface temperature (SST), and other oceanic and atmospheric conditions. Overall, the root-mean-square (rms) errors of non-averaged SMOS SSSs ranged from approximately 0.8-1.08 psu for each in-situ salinity dataset consisting of ARGO measurements and non-ARGO data from CTD and buoy measurements in both local seas and the ocean. All SMOS SSSs exhibited characteristic negative bias errors at a range of -0.50- -0.10 psu in the global ocean and the northwest Pacific, respectively. Both rms and bias errors increased to 1.07 psu and -0.17 psu, respectively, in the East Sea. An analysis of the SSS errors indicated dependence on the latitude, SST, and wind speed. The differences of SMOS-derived SSSs from in-situ salinity data tended to be amplified at high latitudes (40-60°N) and high sea water salinity. Wind speeds contributed to the underestimation of SMOS salinity with negative bias compared with in-situ salinity measurements. Continuous and extensive validation of satellite-observed salinity in the local seas around Korea should be further investigated for proper use.

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References

  1. Abe H. and Ebuchi H., 2014, Evaluation of Sea Surface Salinity observed by Aquarius. Journal of Geophysical Research, 119(11), 8109-8121. https://doi.org/10.1002/2014jc010094
  2. Bhaskar T. V. and Jayaram C., 2015, Evaluation of Aquarius Sea Surface Salinity with Argo Sea Surface Salinity in the Tropical Indian Ocean. IEEE Geoscience and Remote Sensing Letters, 12(6), 1292-1296. https://doi.org/10.1109/LGRS.2015.2393894
  3. Bingham F. M., Howden S. D., and Koblinsky C. J. 2002, Sea surface salinity measurements in the historical database. Journal of Geophysical Research, 107, C12, 8019.
  4. Boutin J., Martin N., Reverdin G., Yin X., and Gaillard F., 2013, Sea surface freshening inferred from SMOS and ARGO salinity: Impact of rain. Ocean Science, 9(1), 183-192. https://doi.org/10.5194/os-9-183-2013
  5. Conkright, M. E., Locarnini, R. A., Garcia, H. E., O'Brien, T. D., Boyer, T. P., Stephens, C., and Antonov, J. I., 2002, World Ocean Atlas 2001: Objective analyses, data statistics, and figures: CD-ROM documentation.
  6. Curry R., Dickson B., and Yashayaev I., Achange in the freshwater balance of the Atlantic Ocean over the past four decades. Nature, 426, 826-829. https://doi.org/10.1038/nature02206
  7. Drucker R. and Riser S. C., 2014, Validation of Aquarius sea surface salinity with Argo: Analysis of error due to depth of measurement and vertical salinity stratification. Journal of Geophysical Research, 119(7), 4626-4637. https://doi.org/10.1002/2014jc010045
  8. Font J., G. Lagerloef S. E., LeVine D. M., Camps A., and Zanife O. Z., 2004, The determination of surface salinity with the European SMOS space mission. IEEE Transactions on Geoscience and Remote Sensing, 42(10), 2196-2205. https://doi.org/10.1109/TGRS.2004.834649
  9. Jacob S. D. and Koblinsky C. J., 2007, Effect of Precipitation on the Upper-Ocean Response to a Hurricane. Monthly weather review. 135(6), 2207-2225. https://doi.org/10.1175/MWR3366.1
  10. Kim S. B., Lee J. H., Matthaeis P. de., Yueh S. H., Hong C. H., Lee J. H., and Lagerloef G. S. E., 2014, Sea surface salinity variability in the East China Sea observed by the Aquarius instrument. Journal of Geophysical Research, 119(1), 7016-7028.
  11. Klemas V., 2011, Remote sensing of sea surface salinity: An overview with case studies. Journal of Coastal Research, 27(5), 830-838. https://doi.org/10.2112/JCOASTRES-D-11-00060.1
  12. Lagerloef G. S. E., 2008, The Aquarius/SAC-D mission: Designed to meet the salinity remote-sensing challenge. Oceanography, 21(1), 68-81. https://doi.org/10.5670/oceanog.2008.68
  13. Lagerloef G. S. E., and Font J., 2010, SMOS and Aquarius/SAC-D missions: The era of spaceborne salinity measurements is about to begin. In oceanography from space (pp 35-58), Springer.
  14. Lagerloef G. S. E., Swift C. T., and LeVine D. M., 1995, Sea surface salinity: The next remote sensing challenge. Oceanography, 8, 44-50. https://doi.org/10.5670/oceanog.1995.17
  15. LeVine D. M., Lagerloef G. S. E., Colomb R., Yueh S. H., and Pellerano F., 2007, Aquarius: An instrument to monitor sea surface salinity from space. IEEE Transactions on Geoscience and Remote Sensing, 45(7), 2040-2050. https://doi.org/10.1109/TGRS.2007.898092
  16. Ratheesh S., Sharma R., and Sikhakolli R., Kumar R., and Basu S. 2013, Assessing Sea Surface Salinity Derived by Aquarius in the Indian Ocean. IEEE Geoscience and Remote Sensing Letters, 11(4), 719-722. https://doi.org/10.1109/LGRS.2013.2277391
  17. Reagan, J., Boyer, T., Antonov, J., and Zweng, M., 2014. Comparison analysis between Aquarius sea surface salinity and World Ocean Database in situ analyzed sea surface salinity. Journal of Geophysical Research: Oceans, 119(11), 8122-8140. https://doi.org/10.1002/2014JC009961
  18. Tang W., Yueh S. H., Fore A. G., and Hayashi A., 2014, Validation of Aquarius sea surface salinity with in situ measurement from Argo floats and moored buoys. Journal of Geophysical Research, 119(9), 6171-6189. https://doi.org/10.1002/2014jc010101
  19. Tranchant B., Testut C. E., Renault L., Ferry N., Birol F., and Brasseur P., 2008, Expected impact of the future SMOS and Aquarius Ocean surface salinity missions in the Mercator Ocean operational system: New perspectives to monitor the ocean circulation. Remote Sensing of Environment, 112(4), 1476-1487. https://doi.org/10.1016/j.rse.2007.06.023
  20. Wong A. P., Johnson G. C., and Owens W. B., 2003, Delayed-Mode Calibration of Autonomous CTD Profiling Float Salinity Data Θ-S climatology. Journal of Atmospheric and Oceanic Technology, 20(2), 30.
  21. Yueh, S. H., Tang, W., Fore, A. G., Neumann, G., Hayashi, A., Freedman, A., and Lagerloef, G. S., 2013, L-band passive and active microwave geophysical model functions of ocean surface winds and applications to Aquarius retrieval. IEEE Transactions on Geoscience and Remote Sensing, 51(9), 4619-4632. https://doi.org/10.1109/TGRS.2013.2266915
  22. Yueh, S. H., West, R., Wilson, W. J., Li, F. K., Njoku, E. G., and Rahmat-Samii, Y., 2001, Error sources and feasibility for microwave remote sensing of ocean surface salinity. IEEE Transactions on Geoscience and Remote Sensing, 39(5), 1049-1060. https://doi.org/10.1109/36.921423