Decadal variations in mixed layer salinity in the Kuroshio Extension recirculation gyre region: influence of precipitation during the warm season
The salinity of the mixed layer in the Kuroshio Extension recirculation gyre (KERG) region (28°–35°N, 141°–160°E) was examined over a period of 20 years (1993–2012), and was found to show low-frequency variations on a decadal (~10 years) timescale: salinity decreased during the periods 1995–2001 and 2006–2009, but increased over the periods 2002–2005 and 2010–2012. Salinity anomalies at the sea surface during the warm season (June–October) influenced salinity in the following winter. These warm-season anomalies were caused by precipitation changes related to the number of low-pressure systems passing over the KERG associated with a westward elongation/eastward shrinkage of the summertime North Pacific subtropical high, which is driven by the Pacific–Japan (PJ) teleconnection pattern.
KeywordsKuroshio Extension recirculation gyre region Mixed layer salinity Precipitation Pacific–Japan (PJ) teleconnection pattern Storm track
We appreciate comments from participants at the Research Meeting on Air–Sea Interaction in 2013, which was part of the Collaborative Research Program of HyARC, Nagoya University. We thank two anonymous reviewers for their valuable suggestions. This study was supported in part by funds from the Japan Society for Promotion of Science [Grant-in-Aid for Young Scientists (B) 15K17756] and from the Ministry of Education, Culture, Sports, Science and Technology [Grant-in-Aid for Scientific Research on Innovative Areas 25106702, “A ‘hot spot’ in the climate system: Extratropical air–sea interaction under the East Asian monsoon system”].
- Boyer TP, Antonov JI, Baranova OK, Garcia HE, Johnson DR, Locarnini RA, Mishonov AV, Seidov D, Smolyar IV, Zweng MM (2009) World Ocean Database 2009, Chapter 1: introduction. In: Levitus S (ed) NOAA Atlas NESDIS 66. US Government Printing Office, Washington, DCGoogle Scholar
- Boyer TP, Antonov JI, Baranova OK, Coleman C, Garcia HE, Grodsky A, Johnson DR, R. Locarnini A, Mishonov AV, O’Brien TD, Paver CR, Reagan JR, Seidov D, Smolyar IV, and Zweng MM (2013) World Ocean Database 2013. Levitus S (Ed), A. Mishonov (Technical Ed) NOAA Atlas NESDIS 72, Silver Spring, MD, p 209Google Scholar
- Masuzawa J (1969) Subtropical mode water. Deep Sea Res 16:463–472Google Scholar
- Nitta T (1987) Convective activities in the tropical western Pacific and their impact on the Northern Hemisphere summer circulation. J Meteor Soc Japan 65:373–390Google Scholar
- Qiu B, Chen S (2010) Eddy–mean flow interaction in the decadally modulating Kuroshio Extension system. Deep-Sea Res 57:1098–1110Google Scholar