# Spatio-Temporal Variation of Cold Water Masses along the Eastern Coast of Korea in 2013 and 2014

• Han, In-Seong (Ocean Climate and Ecology Research Division, National Institute of Fisheries Science) ;
• Park, Myung-Hee (Ocean Climate and Ecology Research Division, National Institute of Fisheries Science) ;
• Min, Seung-Hwan (Ocean Climate and Ecology Research Division, National Institute of Fisheries Science) ;
• Kim, Ju-Yeon (Ocean Climate and Ecology Research Division, National Institute of Fisheries Science)
• Accepted : 2016.05.27
• Published : 2016.05.31
• 33 5

#### Abstract

With the results of observations in 2013 and 2014 including ocean buoys, in-situ investigations and wind data, we examined the spatio-temporal variation of cold water masses along the eastern coast of Korea. Usually, a cold water mass first appears along the northern part of the eastern coast from May to July, and then along the southern part of the eastern coast from late June to mid-August. Cold water masses appear 3~5 times a year and remain for 5~20 days in the southwestern part of the East Sea. A distinctive cold water mass appeared usually in mid-July in this area, the surface temperature of which was below $10^{\circ}C$ in some cases. During the appearance of a cold water mass in the southwestern part of the East Sea, the horizontal temperature gradient was large at the surface and a significant low water temperature below $8^{\circ}C$ appeared at the bottom level. This appearance of cold water masses clearly corresponded to southwesterly winds, which generated coastal upwelling.

#### Acknowledgement

Supported by : National Institute of Fisheries Science

#### References

1. An, H. S.(1974), On the cold water mass around the southeast coast of Korean Peninsula. J. Oceanol. Soc. Kor. Vol. 9, No. 1-2, pp. 10-18.
2. Byun, S. K.(1989), Sea surface cold water near the southeastern coast of Korea: Wind effect. J. Oceanogr. Soc. Kor. Vol. 24, No. 3, pp. 121-131.
3. Han, I. S., J. Lee, L. H. Jang, Y. S. Suh and K. T. Seong(2008), Evidence of vertical mixing caused by high frequency internal waves along the eastern coast of Korea. J. Fish. Sci. Tech. Vol. 11, No. 1, pp. 41-49.
4. Han, K. H., J. H. Kim and S. R. Baek(2002), Seasonal variation of species composition of fishes collected by set net in coastal waters of Ulsan, Korea. Kor. J. Ichthyol. Vol. 14, No. 1, pp. 61-69.
5. Hase, H., J. H. Yoon and W. Koterayama(1999), The current structure of the Tsushima Warm Current along the Japanese coast. J Oceanogr 55, pp. 217-235. https://doi.org/10.1023/A:1007894030095
6. Kim, A. R., S. H. Youn, M. H. Chung, S. C. Yoon and C. H. Moon(2014), The influence of coastal upwelling on phytoplankton community in the southern part of East Sea, Korea. J. Kor. Soc. Oceanogr. Vol. 19, No. 4, pp. 287-301.
7. Kim, C. H. and K. Kim(1983), Characteristics and origin of the cold water mass along the east coast of Korea. J. Kor. Soc. Oceanogr. Vol. 18, No. 1, pp. 73-83.
8. Kim, D. S. and D. H. Kim(2008), Numerical simulation of upwelling appearance near the southeastern coast of Korea. J. Kor. Soc. Mar. Env. Safety. Vol. 14, No. 1, pp. 1-7.
9. Kim, T. H. and G. B. Kim(2010), Distribution of dissolved organic carbon (DOC) in the southwestern East Sea in summer. Ocean and Polar Res. Vol. 32, No. 3, pp. 291-297. https://doi.org/10.4217/OPR.2010.32.3.291
10. Kim, T. S., K. A. Park, X. Li and S. W. Hong(2014), SAR-derived fields at the coastal region in the East/Japan Sea and relation to coastal upwelling. Int. J. Rem. Sens. Vol. 35, pp. 3497-3965.
11. Lee, C. R., C. Park and C. H. Moon(2004), Appearance of cold water and distribution of zooplankton off Ulsan-Gampo area, eastern coastal area of Korea. J. Kor. Soc. Oceanogr. Vol. 9, No. 2, pp. 51-63.
12. Lee, D. K., J. I. Kwon and S. B. Hahn(1998), The wind effect on the cold water formation near Gampo-Ulgi coast. J. Kor. Fish. Soc. Vol. 31, No. 3, pp. 359-371.
13. Lee, J. C.(1983), Variations of sea level and sea surface temperature associated with wind-induced upwelling in the southeast coast of Korea in summer. J. Oceanol. Soc. Kor. Vol. 18, No. 2, pp. 149-160.
14. Lee, J. C. and J. Y. Na(1985), Structure of upwelling off the southeast coast of Korea. J. Oceanol. Soc. Kor. Vol. 20, No. 3, pp. 6-19.
15. Lee, M. O., S. Otake and J. K. Kim(2014), Characteristic of cold water appeared in the southwestern East Sea. J. Kor. Soc. Fish. Mar. Sci. Edu. Vol. 26, No. 3, pp. 455-473.
16. Lee, Y. H., J. M. Shim, Y. S. Kim, J. D. Hwang, S. H. Yoon, C. Lee and H. G. Jin(2007), The variation of water temperature and the mass mortalities of sea squirt, Halocynthia roretzi along Gyeongbuk coasts of the East Sea in summer, 2006. J. Kor. Soc. Mar. Env. Safety. Vol. 13, No. 4, pp. 15-19.
17. NIFS(2013), National Institute of Fisheries Science, Ocean data newsflash #4317, NIFS Newsflash, pp. 1-2.
18. Park, J. H., K. H. Choi and J. H. Lee(1998), The relationship between coastal cold water and catch condition of common squid (Todarodes pacificus STEENSTRUP) in the East Sea of Korea in summer. Bull. Kor. Soc. Fish. Tech. Vol. 34, No. 2, pp. 105-116.
19. Park, K. A. and K. R. Kim(2010), Unprecedented coastal upwelling in the East/Japan Sea and linkage to long-term large-scale variations. Geophy. Res. Lett. Vol. 37, L09603, doi:10.1029/2009GL042231. https://doi.org/10.1029/2009GL042231
20. Park, M. O.(2006), Composition and distribution of phytoplankton with size fraction results at southwester East/Japan Sea. Ocean Sci. Jour. Vol. 42, No. 4, pp. 301-313.
21. Seung, Y. H.(1984), A numerical experiment of the effect of coastline geometry on the upwelling along the east coast of Korea. J. Oceanol. Soc. Kor. Vol. 19, No. 1, pp. 24-30.
22. Suh, Y. S., L. H. Jang and J. D. Hwang(2001), Temporal and spatial variations of the cold waters occurring in the eastern coast of the Korean Peninsula in summer season. J. Kor. Fish. Soc. Vol. 34, No. 5, pp. 435-444.
23. Suh, Y. S. and J. D. Hwang(2005), Study on the cold mass occurrence in the eastern coast of the Korean Peninsula in summer. J. Env. Sci. Vol. 14, No. 10, pp. 945-953.
24. Yang, H. S., S. J. Oh, H. P. Lee, C. H. Moon, M. S. Han and B. K. Kim(1998), Distribution of particulate organic matter in the Gampo upwelling area of the southwestern East Sea. J. Kor. Soc. Oceanogr. Vol. 33, No. 4, pp. 157-167.
25. Yoo, S. J. and J. S. Park(2009), Why is the southwest the most productive region of the East Sea/Sea of Japan?. J. Mar. Sys. Vol. 78, pp. 301-315. https://doi.org/10.1016/j.jmarsys.2009.02.014