Journal of the Korean Society of Marine Environment & Safety (해양환경안전학회지)

The Korean Society of Marine Environment and safety (해양환경안전학회)
권호 표지
DOI QR코드

DOI QR Code

Analysis of the Relationship between the Flow Characteristics of the Tsushima Warm Current and Pacific Decadal Oscillation

대마난류의 유동 특성과 PDO의 관계 분석

  • Seo, Ho-San (Research Center for Ocean Industrial Development, Pukyong National University) ;
  • Chung, Yong-Hyun (Department of Ecological Engineering, Pukyong National University) ;
  • Kim, Dong-Sun (Major of Big Data Convergence, Pukyong National University)
  • 서호산 (부경대학교 해양산업개발연구소) ;
  • 정용현 (부경대학교 생태공학전공) ;
  • 김동선 (부경대학교 빅데이터융합전공)
  • Received : 2022.09.19
  • Accepted : 2022.10.28
  • Published : 2022.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, to understand the factors influencing the flow change the Tsushima Warm Current (TWC), the correlation between the volume transport the TWC, El Niño Southern Oscillation (ENSO), and Pacific Decadal Oscillation (PDO) was analyzed. A calculation of the monthly volume transport of TWC for 25 years (1993-2018) revealed that the seasonal fluctuation cycle was the largest in summer and smallest in winter. Power spectrum analysis to determine the periodicity of the TWC volume transport, Oceanic Niño Undex (ONI), and PDO indicated that the TWC volume transport peaked at a one year cycle, but ONI and PDO showed no clear cycle. Further, to understand the correlation between the TWC transport volume and ONI and PDO, the coherence estimation method was used for analysis. The coherence of ONI and PDO had a high mutual contribution in long-period fluctuations of three years or more but had low mutual contribution in short-period fluctuations within one year. However, the coherence value between the two factors of the TWC volume transport and PDO was 0.7 in the 0.8-1.2 year cycle, which had a high mutual contribution. Meanwhile, the TWC volume transport and PDO have an inverse correlation between period I (1993-2002) and period III (2010-2018). When the TWC maximum transport volume (2.2 Sv or more) was high, the PDO index showed a negative value below -1.0, and the PDO index showed a positive value when the TWC maximum transport volume was (below 2.2 Sv). Therefore, using long-term PDO index data, changes in the TWC transport volume and water temperature in the East Sea coastal area could be predicted.

본 연구에서는 대마난류(Tsushima Warm Current, TWC)의 유동 변화에 영향을 주는 요소를 파악하기 위하여 TWC의 수송량과 태평양 순년진동(Pacific Decadal Oscillation, PDO) 및 엘니뇨 남방진동(El Niño - Southern Oscillation, ENSO)의 상호 관계 분석을 실시하였다. 25년(1993~2018년) 동안의 TWC의 월별 수송량을 계산해보면 하계에 가장 크고 동계에 가장 작게 나타나는 계절변동 주기가 뚜렷하다. TWC 수송량과 PDO 및 ENSO의 한 척도인 Oceanic Niño Index(ONI) 각각의 주기성 파악을 위한 power spectrum 분석결과, TWC 수송량은 1년 주기에서 peak를 보이지만 PDO 및 ONI는 뚜렷한 주기가 나타나지 않았다. 또한, TWC 수송량과 PDO 및 ONI의 상호 관계 파악을 위해 coherence 추정 방법을 이용하여 분석하였다. PDO 및 ONI의 coherence는 3년 이상의 장주기 변동에서 상호 기여도가 높으나 1년 이내의 단주기 변동에서는 상호 기여도가 낮다. 그러나 TWC 수송량과 PDO 두 요소 간 0.8~1.2년 주기에서 coherence 값은 0.7로 상호 기여도가 높다. 한편 서수도를 통과하는 TWC 수송량과 PDO는 I기간(1993~2002년)과 III기간(2010~2018년)에 역상관 관계성을 가진다. TWC 최대 수송량 (2.2 Sv 이상)이 높게 나타나는 시기에 PDO 지수가 -1.0 이하의 음의 값, 2.2 Sv 이하로 작은 시기에 PDO 지수가 양의 값을 나타낸다. 따라서 장기적인 PDO 지수 자료를 이용하면 TWC 수송량 변동 및 동해 연안역의 수온변화를 예측 또한 가능할 것으로 판단된다.

Keywords

Acknowledgement

본 논문 부경대학교 자율창의학술연구비(2021년)에 의하여 연구되었음.

References

  1. Andres, M., J. H. Park, M. Wimbush, X. H. Zhu, H. Nakamura, K. Kim, and K. I. Chang(2009), Manifestation of the Pacific decadal oscillation in the Kuroshio, Geophysical Research Letters, 36(16).
  2. Cho, K. D., C. H. Hong, K. H. Lee, J. H. Yoon, S. K. Yang, Y. K. Choi, D. S. Kim, K. W. Cho, H. D. Kim, and S. W. Kim(2005), Descriptive Physical Oceanography, Pukyong National University Press, pp. 119-121.
  3. Cho, K. W. and J. H. Maeng(2007), Some thoughts on direction to cope with the sea level rise in Korea, Journal of the Korean Society for Marine Environment & Energy, 10(4), pp. 227-234.
  4. Emery, W. J. and R. E. Thomson(1998), Data Analysis Methods in Physical Oceanography, Pergamon Press, pp. 468-487.
  5. Fukudome, K. I., J. H. Yoon, A. Ostrovskii, T. Takikawa, and I. S. Han(2010), Seasonal volume transport variation in the Tsushima Warm Current through the Tsushima Straits from 10 years of ADCP observations, Journal of oceanography, 66(4), pp. 539-551. https://doi.org/10.1007/s10872-010-0045-5
  6. Gershunov, A. and T. P. Barnett(1998), ENSO influence on intraseasonal extreme rainfall and temperature frequencies in the contiguous United States: Observations and model results. Journal of Climate, 11(7), pp. 1575-1586. https://doi.org/10.1175/1520-0442(1998)011<1575:EIOIER>2.0.CO;2
  7. Gordon, A. L. and C. F. Giulivi(2004), Pacific decadal oscillation and sea level in the Japan/East Sea. Deep Sea Research Part I: Oceanographic Research Papers, 51(5), pp. 653-663. https://doi.org/10.1016/j.dsr.2004.02.005
  8. Hong, C. H., K. D. Cho, and H. J. Kim(2001), The relationship between ENSO events and sea surface temperature in the East (Japan) Sea. Progress in oceanography, 49(1-4), pp. 21-40. https://doi.org/10.1016/S0079-6611(01)00014-3
  9. Lee, J. C. and K. I. Chang(2014), Variability of the coastal current off Uljin in summer 2006. Ocean and Polar Research, 36(2), pp. 165-177. https://doi.org/10.4217/OPR.2014.36.2.165
  10. Lee, J. C. and D. H. Kim(2018), Physical Envirionment Associated with Upwelling off the Southeast Coast of Korea. Korean Journal of Fisheries and Aquatic Sciences, 51(5), pp. 579-589. https://doi.org/10.5657/KFAS.2018.0579
  11. Seo, H. S. and D. S. Kim(2020), Effect of El Nino and La Nina on the Coastal Upwelling in East Sea, South Korea, Journal of the Korean Society of Marine Environment & Safety, 26(1), pp. 75-83. https://doi.org/10.7837/kosomes.2020.26.1.075
  12. Seong, K. T., J. D. Hwang, I. S. Han, W. J. Go, Y. S. Suh, and J. Y. Lee(2010), Characteristic for long-term trends of temperature in the Korean waters, Journal of the Korean Society of Marine Environment & Safety, 16(4), pp. 353-360.
  13. Takikawa, T., J. H. Yoon, and K. D. Cho(2005), The Tsushima warm current through Tsushima Straits estimated from ferryboat ADCP data. Journal of Physical Oceanography, 35(6), pp. 1154-1168. https://doi.org/10.1175/JPO2742.1
  14. Teague, W. J., G. A. Jacobs, H. T. Perkins, J. W. Book, K. I. Chang, and M. S. Suk(2002), Low-frequency current observations in the Korea/Tsushima Strait. Journal of Physical Oceanography, 32(6), pp. 1621-1641. https://doi.org/10.1175/1520-0485(2002)032<1621:LFCOIT>2.0.CO;2
  15. Vinay, K. I. and G. P. John(1999), Digital signal processing using MATLAB, Thomson-Engineering, pp. 139-190.
  16. Wu, C. R., Y. L. Wang, and S. Y. Chao(2019), Disassociation of the Kuroshio current with the Pacific decadal oscillation since 1999, Remote Sensing, 11(3), p. 276. https://doi.org/10.3390/rs11030276
  17. Yoo, S. and H. C. Kim(2004), Suppression and enhancement of the spring bloom in the southwestern East Sea/Japan Sea. Deep Sea Research Part II: Topical Studies in Oceanography, 51(10-11), pp. 1093-1111. https://doi.org/10.1016/S0967-0645(04)00102-X
  18. NOAA Climate Prediction Center, https://origin.cpc.ncep.noaa.gov/.
  19. Tokyo Climate Center, https://ds.data.jma.go.jp/tcc/tcc/products/elnino/decadal/pdo_month.html.