Journal of Environmental Science International (한국환경과학회지)

The Korean Environmental Sciences Society (한국환경과학회)
권호 표지
DOI QR코드

DOI QR Code

Temporal and Spatial Variability of Sound Speed in the Sea around the Ieodo

이어도 주변해역에서 수중음속의 시공간적 변동성

  • 박경주 (해군사관학교 해양학과)
  • Received : 2020.09.08
  • Accepted : 2020.11.16
  • Published : 2020.11.30
Download PDF
⟨ Previous Next ⟩

Abstract

The impact of sound speed variability in the sea is the very important on acoustic propagation for the underwater acoustic systems. Understanding of the temporal and spatial variability of ocean sound speed in the sea around the Ieodo were obtained using oceanographic data (temperature, salinity). from the Korea Oceanographic Data Center, collected by season for 17 years. The vertical distributions of sound speed are mainly related to seasonal variations and various current such as Chinese coastal water, Yellow Sea Cold Water (YSCW), Kuroshio source water. The standard deviations show that great variations of sound speed exist in the upper layer and observation station between 16 and 18. In order to quantitatively explain the reason for sound speed variations, Empirical Orthogonal Function (EOF) analysis was performed on sound speed data at the Line 316 covering 68 cruises between 2002 and 2018. Three main modes of EOFs respectively revealed 55, 29, and 5% the total variance of sound speed. The first mode of the EOFs was associated with influence of surface heating. The second EOFs pattern shows that contributions of YSCW and surface heating. The first and second modes had seasonal and inter-annul variations.

Keywords

References

  1. Beardsley, R. C., Limeburner, R., Yu, H., Cannon, G. A., 1985, Discharge of the Changjiang(Yangtze River) into the East China Sea, Cont. Shelf Res., 4, 57-76. https://doi.org/10.1016/0278-4343(85)90022-6
  2. Chang, P. H., Isobe, A., 2003, A numerical study on the Changjiang diluted water in the Yellow and East China Seas, J. Geophys. Res., 108, 3299. https://doi.org/10.1029/2002jc001749
  3. Chen, C., Beardsley, R. C., Limeburner, R., Yu, H., Kim, K., 1994, Comparison of winter and summer hydrographic observation in the Yellow and East China Sea and adjacent Kuroshio during 1986, Cont. Shelf Res., 14, 909-929.
  4. Clay, C. S., Medwin, H., 1977, Acoustical oceanography : principles and applications, John Wiley & Sons, Inc., New York, 554.
  5. Emery, W. J., Thomson, R. E., 2014, Data analysis methods in physical oceanography, 3rd ed., Elsevier, New York, 319-343.
  6. Fritsch, F. N., Carlson, R. E., 1980, Monotone piecewise cubic interpolation, SIAM J. Numer. Anal., 17, 238-246. https://doi.org/10.1137/0717021
  7. Guan, B., 1984, Major features of the shallow water hydrography in the East China Sea and Huanghai Sea, In: T. Ichieye(Ed.), Ocean hydrodynamics of the Japan and East China Sea, Elsevier Oceanography Series, 39, 1-13.
  8. Hur, H. B., Jacobs, G. A., Teague, W. J., 1999, Monthly variations of water masses in the Yellow and East China Seas, November 6, 1988, J. Oceanogr., 55, 171-184. https://doi.org/10.1023/A:1007885828278
  9. Ichikawa, H., Beardsley, R. C., 2002, The current system in the Yellow and East China Seas, J. Oceangr. Soc. Japan, 58, 77-92.
  10. Jang, S. T., Lee, J. H., Hong, C. S., 2007, Mixing of sea waters in the northern part of the East China Sea in Summer, J. Ocean. Soc. Kor., 12, 390-399.
  11. Jang, S. T., Lee, J. H., Kim, C. H., Jang, C. J., Jang, Y. S., 2011, Movement of cold water mass in the Northern East China Sea in summer, J. Ocean. Soc. Kor., 16, 1-13.
  12. Knauss, J. A., 1978, Introduction to physical oceanography, Prentice-Hall, New Jersey, 3-27.
  13. Kim, K., Rho, H. K., Lee, S. H., 1991, Water masses and circulation around Cheju-Do in summer, J. Oceanogr. Soc. Kor., 26, 262-277.
  14. Kim, H. S., Kim, J. H., Paeng, D. G., 2015, Analysis of surface sound channel by low salinity water and its mid-frequency acoustic characteristics in the East China Sea and the Gulf of Guinea, J. Acoust. Soc. Kr., 34, 1-11. https://doi.org/10.7776/ASK.2015.34.1.001
  15. Korea Oceanographic Data Center, 2019 http://kodc.nfrdi.re.kr/page?id=obs_04_01
  16. Lee, J. H., Kim, C. H., 2013, Long-term variability of sea surface temperature in the East China Sea: a review, Ocean and Polar Res., 35, 171-179. https://doi.org/10.4217/OPR.2013.35.2.171
  17. Lie, H. J., Cho, C. H., Lee, J. H., Lee, S., 2003, Structure and eastward extension of the Changjiang river plume in the East China Sea, J. Geophys. Res., 108, 3077. https://doi.org/10.1029/2001jc001194
  18. Mackenzie, K. V., 1981, Nine-term equation for the sound speed in the oceans, J. Acoust. Soc. Am., 70, 807-812. https://doi.org/10.1121/1.386920
  19. Navarra, A., Simoncini, V., 2010, A guide to empirical orthogonal functions for climate data analysis, Springer, New York, 42.
  20. Oh, K. H., Park, Y. G., Lim, D. I., Jung, H. S., Shim, J. S., 2006, Characteristics of temperature and salinity observed at the Ieodo ocean research station, J. Mar. Env. Soc. Kor., 9, 225-234.
  21. Urick, R. J., 1983, Principles of underwater sound, 3rd ed., McgrawHill, New York, 423.
  22. Wang, W., 1988, Yangtze brackish water plume-circulation and diffusion, Prog. Oceanog., 21, 373-385. https://doi.org/10.1016/0079-6611(88)90015-8
  23. Wang, F., Liu, C., Meng, Q., 2012, Effect of the Yellow Sea warm current fronts on the westward shift of the Yellow Sea warm tongue in winter, Cont. Shelf Res., 45, 98-107. https://doi.org/10.1016/j.csr.2012.06.005
  24. Yoon, S. C., Youn, S. H., Whang, J. D., Suh, Y. S., Yoon, Y. Y., 2015, Long-term variation in ocean environmental conditions of the northern East China Sea, J. Kor. Sci. Mar. Environ. Energy., 18, 189-206.