Journal of Advanced Marine Engineering and Technology

The Korean Society of Marine Engineering (한국마린엔지니어링학회)
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Analysis of haline channel formed in the East China Sea and the Atlantic Ocean using the T-S gradient diagram

  • Kim, Juho (Department of Ocean System Engineering, Jeju National University) ;
  • Kim, Hansoo (Department of Ocean System Engineering, Jeju National University) ;
  • Paeng, Dong-Guk (Department of Ocean System Engineering, Jeju National University)
  • Received : 2013.11.06
  • Accepted : 2014.01.03
  • Published : 2014.02.28
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Abstract

In case of any coastal ocean near the mouth of huge rivers, low salinity water can be formed due to its large amount of freshwater discharge. For the acoustic analysis on the low salinity environment, some oceanographic data of the East China Sea and the Atlantic Ocean were collected through KODC (Korea Oceanographic Data Center) and NODC (National Oceanographic Data Center) online service. In this paper, the T-S gradient diagram is introduced to show a relation between the gradients of temperature and salinity in view of acoustic surface channel formation. Existence of haline channel, quantitative contribution of gradients of salinity and temperature, effectiveness of the channel formation can be known by the T-S gradient diagram. After applying the collected data into the diagram, tropical regions of the Atlantic Ocean show strong haline channel due to its nearly invariant temperature and drastic change of salinity with depth. The averaged transmission loss in the channel is about 5.7 ~ 7.5 dB less than that out of the channel by the results of acoustic propagation model (RAM: Range independent Acoustic Model). On the other hand, the East China Sea and temperate region of the Atlantic ocean have weaker haline channel with less difference of the averaged transmission loss between in and out of the channel as 3.2 ~ 6.0 dB. Although data samples used in this study have limitation to represent the general physical structures of the three ocean regions, the T-S gradient diagram is shown to be useful and acoustic field affected by low salinity environment is investigated in this study.

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References

  1. T. U. Bhaskar, D. Swain, and M. Ravichandran, "Seasonal variability of sonic layer depth in the central arabian sea", Journal of Ocean Science, vol. 43, no. 3, pp. 147-152, 2008. https://doi.org/10.1007/BF03020695
  2. J. Salisbury, D. Vandemark, J. Campbell, C. Hunt, D. Wisser, and N. Reul, "Spatial and temporal coherence between Amazon River discharge, salinity, and light absorption by colored organic carbon in western tropical Atlantic surface waters", Journal of Geophysical Research, vol. 116 (C00H02), pp. 1-14, 2011.
  3. E. D. Palma, R. P. Matano, and A. R. Piola, "A numerical study of the Southwestern Atlantic Shelf circulation: Barotropic response to tidal and wind forcing", Journal of Geophysical Research, vol. 109 (C08014), pp 1-17, 2004.
  4. N. S. Banas, P. MacCready, and B. M. Hickey, "The Columbia River plume as cross-shelf exporter and along-coast barrier", Continental Shelf Research, vol. 29, pp 292-301, 2009. https://doi.org/10.1016/j.csr.2008.03.011
  5. R. C. Beardsley, R. Limeburner, H. Yu, and G. A. Cannon, "Discharge of the Changjiang (Yangtze River) into the East China Sea", Continental Shelf Research, vol. 4, no. 1, pp. 57-76, 1985. https://doi.org/10.1016/0278-4343(85)90022-6
  6. P. C. Fiedler and L. D. Talley, "Hydrography of the eastern tropical Pacific: A review", Progress in Oceanography, vol. 69, pp. 143-180, 2006. https://doi.org/10.1016/j.pocean.2006.03.008
  7. K. H. Oh, Y. G. Park, D. I. Lim, H. S. Jung, and J. S. Shin, "Characteristics of temperature and salinity observed at the Ieodo ocean research station", Journal of the Korean Society for Marine Environmental Engineering, vol. 9, no. 4, pp. 225-234, 2006 (in Korean).
  8. S. E. Dosso and N. R. Chapman, "Acoustic propagation in a shallow sound channel in the Northeast Pacific Ocean", Journal of the Acoustical Society of America, vol. 75, no. 2, pp. 141-147, 1992.
  9. N. P. Bulgakov, Y. V. Artamonov, P. D. Lomakin, and V. N. Cheremin, "Acoustic properties of surface water masses in the tropical Atlantic and their seasonal variability", Soviet Journal of Physical Oceanography, vol. 3, no. 2, pp. 141-147, 1992. https://doi.org/10.1007/BF02197620
  10. J. Kim, T. H. Bok, D. G. Paeng, I. C. Pang, and C. Lee, "Acoustic channel formation and sound speed variation by low-salinity water in the western sea of Jeju during summer", Journal of the Acoustical Society of Korea, vol. 32, no.1, pp. 1-13, 2013 (in Korean). https://doi.org/10.7776/ASK.2013.32.1.001
  11. NODC (National Oceanographic Data Center),www.nodc.moaa.gov/OC5/SELECT/dbsearch/ dbsearch.thml.
  12. KODC (Korea Oceanographic Data Center), http://kodc.nfrdi.re.kr
  13. H. Medwin, "Speed of sound in water: A simple Equation for realistic parameters", Journal of the Acoustical Society of America, vol. 58, no. 6, pp. 1318-1319, 1975. https://doi.org/10.1121/1.380790
  14. M. D. Collins, "Users Guide for RAM Versions 1.0 and 1.0p", ftp://ftp.apl.washington.edu/archive/whales/Haro_Strait/rrsfc/ram.pdf, Acessed November 9, 2013

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