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Origin of near-surface high-salinity water observed in the Kuroshio Extension region

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Abstract

Hydrographic data in the Kuroshio Extension (KE) region from 2008 to 2010 show large year-to-year variability in near-surface salinity, including a very large anomalous event in February 2010. During this event, the deep winter mixed layer in the southern KE region had higher salinity than had existed during the previous summer in September 2009. Our analysis shows that advection from the Philippine Sea along the western branch of the North Pacific subtropical gyre, taking approximately 9 months, resulted in this large salinity anomaly in February 2010 and contributes to the interannual salinity variability in the southern KE region.

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Acknowledgments

The authors thank the captains, crew, technicians, and scientists for collecting ship data on board the R/V Kaiyo, R/V Mirai, and R/V Syoyo-maru (cruise numbers: MR08-03, MR09-04, MR10-01 leg 2, MR10-06, KY09-07, and SY08-04), for the observations by KEO and K-TRITON (JKEO) buoy systems, and for special efforts by Drs. K. Matsumoto, M. Honda, and Y. Kashino. The authors also thank Drs. M. Konda, S. Hosoda, and T. Hasegawa for their helpful comments. Thanks are extended to anonymous reviewers for their helpful comments. This work was partly supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Grant-in-Aid for Scientific Research on Innovative Areas (22106007).

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Correspondence to Akira Nagano.

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Nagano, A., Uehara, K., Suga, T. et al. Origin of near-surface high-salinity water observed in the Kuroshio Extension region. J Oceanogr 70, 389–403 (2014). https://doi.org/10.1007/s10872-014-0237-5

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  • DOI: https://doi.org/10.1007/s10872-014-0237-5

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