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http://dx.doi.org/10.5467/JKESS.2020.41.5.469

Validation of Satellite SMAP Sea Surface Salinity using Ieodo Ocean Research Station Data  

Park, Jae-Jin (Department of Science Education, Seoul National University)
Park, Kyung-Ae (Department of Earth Science Education/Research Institute of Oceanography, Seoul National University)
Kim, Hee-Young (Department of Science Education, Seoul National University)
Lee, Eunil (Ocean Research Division, Korea Hydrographic and Oceanographic Agency)
Byun, Do-Seong (Ocean Research Division, Korea Hydrographic and Oceanographic Agency)
Jeong, Kwang-Yeong (Ocean Research Division, Korea Hydrographic and Oceanographic Agency)
Publication Information
Journal of the Korean earth science society / v.41, no.5, 2020 , pp. 469-477 More about this Journal
Abstract
Salinity is not only an important variable that determines the density of the ocean but also one of the main parameters representing the global water cycle. Ocean salinity observations have been mainly conducted using ships, Argo floats, and buoys. Since the first satellite salinity was launched in 2009, it is also possible to observe sea surface salinity in the global ocean using satellite salinity data. However, the satellite salinity data contain various errors, it is necessary to validate its accuracy before applying it as research data. In this study, the salinity accuracy between the Soil Moisture Active Passive (SMAP) satellite salinity data and the in-situ salinity data provided by the Ieodo ocean research station was evaluated, and the error characteristics were analyzed from April 2015 to August 2020. As a result, a total of 314 match-up points were produced, and the root mean square error (RMSE) and mean bias of salinity were 1.79 and 0.91 psu, respectively. Overall, the satellite salinity was overestimated compare to the in-situ salinity. Satellite salinity is dependent on various marine environmental factors such as season, sea surface temperature (SST), and wind speed. In summer, the difference between the satellite salinity and the in-situ salinity was less than 0.18 psu. This means that the accuracy of satellite salinity increases at high SST rather than at low SST. This accuracy was affected by the sensitivity of the sensor. Likewise, the error was reduced at wind speeds greater than 5 m s-1. This study suggests that satellite-derived salinity data should be used in coastal areas for limited use by checking if they are suitable for specific research purposes.
Keywords
sea surface salinity; SMAP; satellite salinity; Ieodo ocean research station; accuracy;
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Times Cited By KSCI : 6  (Citation Analysis)
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1 Abe, H., and Ebuchi, N., 2014, Evaluation of seasurface salinity observed by Aquarius. Journal of Geophysical Research: Oceans, 119(11), 8109-8121.   DOI
2 Bao, S., Wang, H., Zhang, R., Yan, H., and Chen, J., 2019, Comparison of satellitederived sea surface salinity products from SMOS, Aquarius, and SMAP. Journal of Geophysical Research: Oceans, 124(3), 1932-1944.   DOI
3 Barré, H. M., Duesmann, B., and Kerr, Y. H., 2008, SMOS: The mission and the system. IEEE Transactions on Geoscience and Remote Sensing, 46(3), 587-593.   DOI
4 Beardsley, R. C., Limeburner, R., Yu, H., and Cannon, G. A., 1985, Discharge of the Changjiang (Yangtze river) into the East China Sea. Continental Shelf Research, 4(1-2), 57-76.   DOI
5 Chang, P. H. and Isobe, A., 2003, A numerical study on the Changjiang diluted water in the Yellow and East China seas. Journal of Geophysical Research: Oceans, 108(C9) 3229.   DOI
6 Choi, D. Y., Woo, H. J., Park, K., Byun, D. S., and Lee, E., 2018, Validation of sea surface wind speeds from satellite altimeters and relation to sea state bias-focus on wind measurements at Ieodo, Marado, Oeyeondo Stations. Journal of the Korean Earth Science Society, 39(2), 139-153.   DOI
7 Delcroix, T., and Murtugudde, R., 2002, Sea surface salinity changes in the East China Sea during 1997-2001: Influence of the Yangtze River. Journal of Geophysical Research: Oceans, 107(C12), SRF-9.
8 Grodsky, S. A., Reul, N., Bentamy, A., Vandemark, D., and Guimbard, S., 2019, Eastern Mediterranean salinification observed in satellite salinity from SMAP mission. Journal of Marine Systems, 198, 103190.   DOI
9 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: Oceans, 119(7), 4626-4637.   DOI
10 Fournier, S., Lee, T., Tang, W., Steele, M., and Olmedo, E., 2019, Evaluation and intercomparison of SMOS, Aquarius, and SMAP sea surface salinity products in the Arctic Ocean. Remote Sensing, 11(24), 3043.   DOI
11 Helm, K. P., Bindoff, N. L., and Church, J. A., 2010, Changes in the global hydrologicalcycle inferred from ocean salinity. Geophysical Research Letters, 37(18), L18701.   DOI
12 Hwang, K., and Jung, S., 2012, Decadal changes in fish assemblages in waters near the Ieodo ocean research station (East China Sea) in relation to climate change from 1984 to 2010. Ocean Science Journal, 47(2), 83-94.   DOI
13 Kim, K., Rho, H. K., and Lee, S. H., 1991, Water masses and circulation around Cheju-do in summer. Journal of the Oceanological Society of Korea, 26, 262-277.
14 Moon, I. J., Shim, J. S., Lee, D. Y., Lee, J. H., Min, I. K., and Lim, K. C., 2010, Typhoon researches using the Ieodo Ocean Research Station: Part I. Importance and present status of typhoon observation. Atmosphere, 20(3), 247-260.
15 Kim, S. B., Lee, J. H., de Matthaeis, P., Yueh, S., Hong, C. S., Lee, J. H., and Lagerloef, G., 2014, Sea surface salinity variability in the East China Sea observed by the Aquarius instrument. Journal of Geophysical Research: Oceans, 119(10), 7016-7028.   DOI
16 Kim, S. S., Go, W. J., Jo, Y. J., Lee, P. Y., and Jeon, K. A., 1998, Low salinity anomaly and nutrient distribution at surface waters of the South Sea of Korea during 1996 summer. Journal of the Korean Society of Oceanography, 3, 165-169.
17 Lagerloef, G., Colomb, F. R., Le Vine, D., Wentz, F., Yueh, S., Ruf, C., and Feldman, G., 2008, The Aquarius/SAC-D mission: Designed to meet the salinity remote-sensing challenge. Oceanography, 21(1), 68-81.   DOI
18 Lie, H.-J., Cho, C.-H., Lee, J.-H., and Lee, S., 2003, Structure and eastward extension of the Changjiang River plume in the East China Sea. Journal of Geophysical Research, 108(C3), 3077.   DOI
19 Lie, H.-J., 1986, Summertime hydrographic features in the south eastern Hwanghae. Progress in Oceanography, 17, 229-242.   DOI
20 O'Carroll, A. G., Eyre, J. R., and Saunders, R. W., 2008, Three-way error analysis between AATSR, AMSR-E, and in situ sea surface temperature observations. Journal of Atmospheric and Oceanic Technology, 25(7), 1197-1207.   DOI
21 Wang W., 1988, Yangtze brackish water plume-circulation and diffusion. Progress in Oceanography, 21, 373-385.   DOI
22 Oh, H. M., and Ha, K. J., 2005, Analysis of marine meteorological characteristics at Ieodo ocean research station from 2003 to 2004. Atmosphere, 41(5), 671-680.
23 Reul, N., Fournier, S., Boutin, J., Hernandez, O., Maes, C., Chapron, B., and Kerr, Y., 2014, Sea surface salinity observations from space with the SMOS satellite: A new means to monitor the marine branch of the water cycle. Surveys in Geophysics, 35(3), 681-722.   DOI
24 Tang, W., Fore, A., Yueh, S., Lee, T., Hayashi, A., Sanchez-Franks, A., and Baranowski, D., 2017, Validating SMAP SSS with in situ measurements. Remote Sensing of Environment, 200, 326-340.   DOI
25 Woo, H. J., Park, K. A., Byun, D. S., Lee, J., and Lee, E., 2018, Characteristics of the differences between significant wave height at Ieodo Ocean Research Station and satellite altimeter-measured data over a decade (2004-2016). The Sea, 23(1), 1-19.   DOI
26 Woo, H. J., Park, K. A., Choi, D. Y., Byun, D. S., Jeong, K. Y., and Lee, E. I., 2019, Comparison of multi-satellite sea surface temperatures and in-situ temperatures from Ieodo Ocean Research Station. Journal of the Korean Earth Science Society, 40(6), 613-623.   DOI