Abstract
The Kerama Gap is an important passage for water exchange between the East China Sea (ECS) and the northwestern Pacific (NP). The mean Kerama Gap transport (KGT) is small into the ECS (~ 2.0 Sv) but with a large standard deviation (~ 4.5 Sv), which has a significant influence on the variation of Kuroshio transport. The effects of mesoscale eddies on the variation of KGT are investigated by using a 25-year Pacific Hybrid Coordinate Ocean Model from 1979 to 2003. Model results show that the variation of KGT is mainly determined by the variation of sea level difference between the northeast and southwest of the Kerama Gap, and these differences are dominated by the westward propagating mesoscale eddies. The effects of mesoscale eddies depend on the meridional location of these eddies. When the anticyclonic (cyclonic) eddy is located in the northeast of the Kerama Gap or the cyclonic (anticyclonic) eddy is located in the southwest of the Kerama Gap, the KGT shows a strong positive (negative) anomaly. However, when the eddy is located in the central region of the Kerama Gap, the KGT shows a relatively smaller anomaly. Besides, the variation of Kuroshio, strongly influenced by the eddies east of Taiwan, also plays an important role in influencing the variation of KGT. When the Kuroshio transport crossing the upstream section of the Kerama Gap is high (low) or the Kuroshio central position shifts to (away from) the Kerama Gap there will be more (less) water flow from the ECS to the NP.
Similar content being viewed by others
References
Akitomo K (2008) Effects of stratification and mesoscale eddies on Kuroshio path variation south of Japan. Deep Sea Res Part I 55:997–1008
Ambe D, Imawaki S, Uchida H, Ichikawa K (2004) Estimating the Kuroshio axis south of Japan using combination of satellite altimetry and drifting buoys. J Oceanogr 60:375–382
Andres M, Cenedese C (2013) Laboratory experiments and observations of cyclonic and anticyclonic eddies impinging on an island. J Geophys Res Oceans 118:762–773
Andres M, Park J-H, Wimbush M, Zhu X-H, Chang K-I, Ichikawa H (2008a) Study of the Kuroshio/Ryukyu current system based on satellite-altimeter and in situ measurements. J Oceanogr 64:937–950
Andres M, Wimbush M, Park JH, Chang KI, Lim BH, Watts D, Ichikawa H, Teague WJ (2008b) Observations of Kuroshio flow variations in the East China Sea. J Geophys Res Oceans 113(C5):15
Andres M, Jan S, Sanford T, Mensah V, Centurioni L, Book J (2015) Mean structure and variability of the Kuroshio from Northeastern Taiwan to Southwestern Japan. Oceanography 348:728–730
Andres M, Mensah V, Jan S, Chang MH, Yang YJ, Lee CM, Ma B, Sanford TB (2017) Downstream evolution of the Kuroshio’s time-varying transport and velocity structure. J Geophys Res Oceans 122:3519–3542
Bleck R (2002) An oceanic general circulation model framed in hybrid isopycnic-Cartesian coordinates. Ocean modelling 4:55–88
Cenedese C (2002) Laboratory experiments on mesoscale vortices colliding with a seamount. J Geophys Res Oceans 107(C6):6-1–6-14
Cenedese C, Adduce C, Fratantoni DM (2005) Laboratory experiments on mesoscale vortices interacting with two islands. J Geophys Res Oceans 110(C9):919–931
Chaigneau A, Eldin G, Dewitte B (2009) Eddy activity in the four major upwelling systems from satellite altimetry (1992–2007). Prog Oceanogr 83:117–123
Chang Y, Miyazawa Y, Guo X (2015) Effects of the STCC eddies on the Kuroshio based on the 20-year JCOPE2 reanalysis results. Prog Oceanogr 135:64–76
Chelton DB, Schlax MG, Samelson RM, De Szoeke RA (2007) Global observations of large oceanic eddies. Geophys Res Lett 34:87–101
Chelton DB, Schlax MG, Samelson RM (2011) Global observations of nonlinear mesoscale eddies. Prog Oceanogr 91:167–216
Chen G, Hou Y, Chu X (2011) Mesoscale eddies in the South China Sea: mean properties, spatial temporal variability, and impact on thermohaline structure. J Geophys Res Oceans 116:102–108
Cummings JA (2005) Operational multivariate ocean data assimilation. Q J R Meteorol Soc 131:3583–3604
Cummings JA, Smedstad OM (2013) Variational data assimilation for the global ocean. Springer, Berlin
Gawarkiewicz G, Jan S, Lermusiaux PFJ, Mcclean JL (2011) Circulation and intrusions northeast of Taiwan: chasing and predicting uncertainty in the cold dome. Oceanography 24:110–121
Godfrey J (1989) A Sverdrup model of the depth-integrated flow for the world ocean allowing for island circulations. Geophys Astrophys Fluid Dyn 45:89–112
Halliwell GR (2004) Evaluation of vertical coordinate and vertical mixing algorithms in the HYbrid-Coordinate Ocean Model (HYCOM). Ocean Model 7:285–322
Han S, Xu C, Wu H, Wang G, Pei J, Fan Y, Wang X (2016) Study on the mesoscale eddies around the Ryukyu Islands. Acta Oceanol Sin 35:38–45
Helber RW, Townsend TL, Barron CN, Dastugue JM, Carnes MR (2013) Validation test report for the improved synthetic ocean profile (ISOP) system, part I: Synthetic profile methods and algorithm (No. NRL/MR/7320--13-9364). Naval research lab stennis detachment stennis space center ms oceanography div
Ho CR, Hsu PC, Lin CC, Huang SJ (2016) Variations of Kuroshio axis east of Taiwan from satellite altimetry. In: EGU General Assembly Conference, vol 18. EGU General Assembly Conference Abstracts, p 3800
Hsin YC, Qiu B, Chiang TL, Wu CR (2013) Seasonal to interannual variations in the intensity and central position of the surface Kuroshio east of Taiwan. J Geophys Res Oceans 118:4305–4316
Hsu PC, Lin CC, Ho CR (2015) Variations of the axis of the Kuroshio east of Taiwan affected by mesoscale eddies. In: International conference on earth observation and societal impacts and Iclei resilience forum, Kaohsiung, Taiwan
Hwang C, Wu CR, Kao R (2004) TOPEX/Poseidon observations of mesoscale eddies over the subtropical countercurrent: kinematic characteristics of an anticyclonic eddy and a cyclonic eddy. J Geophys Res Atmos 109:371–375
Ichikawa K (2001) Variation of the Kuroshio in the Tokara Strait induced by meso-scale eddies. J Oceanogr 57:55–68
Jin B, Wang G, Liu Y, Zhang R (2010) Interaction between the East China Sea Kuroshio and the Ryukyu Current as revealed by the self-organizing map. J Geophys Res Oceans 115(C12):168–172
Kelly KA, Thompson L, Cheng W, Metzger EJ (2007) Evaluation of HYCOM in the Kuroshio extension region using new metrics. J Geophys Res Oceans 112(C1):18
Lee I-H, Ko DS, Wang Y-H, Centurioni L, Wang D-P (2013) The mesoscale eddies and Kuroshio transport in the western North Pacific east of Taiwan from 8-year (2003–2010) model reanalysis. Ocean Dyn 63:1027–1040
Liu Z, Na H, Nakamura H, Nishina A, Park JH, Tracey K, Wimbush M (2012) Kerama Gap 2009–2011 data report. GSO Technical report no. 2012-02, 2:34
Min HS (2016) Variation of the Kuroshio axis in the East China Sea. In: EGU General Assembly Conference, Vienna, Austria, 17-22 April, 2016. vol 18. p 5466
Na H, Wimbush M, Park JH, Nakamura H, Nishina A (2014) Observations of flow variability through the Kerama Gap between the East China Sea and the Northwestern Pacific. J Geophys Res Oceans 119:689–703
Nagano A, Ichikawa H, Miura T, Ichikawa K, Konda M, Yoshikawa Y, Obama K, Murakami K (2007) Current system east of the Ryukyu Islands. J Geophys Res Oceans 112(C6):137–154
Nakamura H, Nishina A, Ichikawa H, Nonaka M, Sasaki H (2008) Deep countercurrent beneath the Kuroshio in the Okinawa Trough. J Geophys Res Oceans 113(C6):1394–1404
Nakamura H, Nonaka M, Sasaki H (2010) Seasonality of the Kuroshio path destabilization phenomenon in the Okinawa Trough: a numerical study of its mechanism. J Phys Oceanogr 40:530–550
Nakamura H, Nishina A, Liu Z, Tanaka F, Wimbush M, Park JH (2013) Intermediate and deep water formation in the Okinawa Trough. J Geophys Res Oceans 118:6881–6893
Nishina A, Nakamura H, Park JH, Hasegawa D, Tanaka Y, Seo S, Hibiya T (2016) Deep ventilation in the Okinawa Trough induced by Kerama Gap overflow. J Geophys Res Oceans 121:6092–6102
Pedlosky J (1987) Geophysical fluid dynamics. Gordon and Breach, vol 46. no 4, pp 201–238
Pedlosky J, Pratt LJ, Spall MA, Helfrich KR (1997) Circulation around islands and ridges. J Mar Res 55:1199–1251
Soeyanto E, Guo X, Ono J, Miyazawa Y (2014) Interannual variations of Kuroshio transport in the East China Sea and its relation to the Pacific Decadal Oscillation and mesoscale eddies. J Geophys Res Oceans 119:3595–3616
Tanabe A, Cenedese C (2008) Laboratory experiments on mesoscale vortices colliding with an island chain. J Geophys Res Oceans 113(C4):535–547
Thoppil PG, Metzger EJ, Hurlburt HE, Smedstad OM, Ichikawa H (2016) The current system east of the Ryukyu Islands as revealed by a global ocean reanalysis. Prog Oceanogr 141:239–258
Tsai CJ, Andres M, Jan S, Mensah V, Sanford TB, Lien RC, Lee CM (2015) Eddy-Kuroshio interaction processes revealed by mooring observations off Taiwan and Luzon. Geophys Res Lett 61:1–6
Yan XM, Che S (2015) An altimetric transport index for Kuroshio inflow northeast of Taiwan Island. Sci China Earth Sci 58:697–706
Yan XM, Zhu XH, Pang C, Zhang L (2016) Effects of mesoscale eddies on the volume transport and branch pattern of the Kuroshio East of Taiwan. J Geophys Res Oceans 121:7683–7700
Yang Y, Liu C, Hu J, Koga M (1999) Taiwan Current (Kuroshio) and impinging eddies. J Oceanogr 55:609–617
Yang G, Wang F, Li Y, Lin P (2013) Mesoscale eddies in the northwestern subtropical Pacific Ocean: statistical characteristics and three-dimensional structures. J Geophys Res Oceans 118:1906–1925
Yang YJ, Jan S, Chang MH, Wang J, Mensah V, Kuo TH, Tsai CJ, Lee CY, Andres M, Centurioni L (2015) Mean structure and fluctuations of the Kuroshio East of Taiwan from in situ and remote observations. Oceanography 28:74–83
Yu Z, Metzger EJ, Thoppil P, Hurlburt HE, Zamudio L, Smedstad OM, Na H, Nakamura H, Park J-H (2015) Seasonal cycle of volume transport through Kerama Gap revealed by a 20-year global HYbrid Coordinate Ocean Model reanalysis. Ocean Model 96:203–213
Zhou WZ, Yu F, Nan F (2017) Water exchange through the Kerama Gap estimated with a 25-year Pacific Hybrid Coordinate Ocean Model. Chin J Oceanol Limnol 6:1–16
Zhu X-H, Ichikawa H, Ichikawa K, Takeuchi K (2004) Volume transport variability southeast of Okinawa Island estimated from satellite altimeter data. J Oceanogr 60:953–962
Zhu X, Park J-H, Huang D (2008) Observation of baroclinic eddies southeast of Okinawa Island. Sci China Ser D Earth Sci 51:1802–1812
Zhu X-H, Huang D, Guo X (2010) Autumn intensification of the Ryukyu Current during 2003–2007. Sci China Earth Sci 53:603–609
Acknowledgements
The authors thank the Archiving, Validation and Interpretation of Satellite Oceanographic (AVISO) for providing the ADT and SLA datasets (http://www.aviso.oceanods.com), Dudley Chelton and Michael Schlax for the 4th release of the trajectories of mesoscale eddies (http://wombat.coas.oregonstate.edu/eddies/), the Global Ocean Data Assimilation Experiment (GODAE) for providing the Pacific HYCOM outputs (ftp://ftp.hycom.org/datasets/PACa0.08/). This work was jointly supported by the National Natural Science Foundation of China (Grant no. 41676005), the National Program on Global Climate Change and Air–Sea Interaction (GASI-IPOVAI-01-06), the CAS Interdisciplinary Innovation Team, the NSFC Innovative Group Grant (Project no. 41421005), and the NSFC-Shandong Joint Found for Marine Science Research Center (Grant no. U1406401).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zhou, WZ., Yu, F., Nan, F. et al. Effects of mesoscale eddies on the variation of water exchange through the Kerama Gap. J Oceanogr 74, 263–275 (2018). https://doi.org/10.1007/s10872-017-0456-7
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10872-017-0456-7