Changes in water properties around North Pacific intermediate water between the 1980s, 1990s and 2000s

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• 作者：Shinya Kouketsu ; Masao Fukasawa ; Daisuke Sasano ; Yuichiro Kumamoto ; Takeshi Kawano ; Hiroshi Uchida ; Toshimasa Doi
• 关键词：NPIW ; WHP ; Decadal change ; Apparent oxygen utilization
• 刊名：Deep Sea Research Part II: Topical Studies in Oceanography
• 出版年：2010
• 出版时间：July 2010
• 年：2010
• 卷：57
• 期：13-14
• 页码：1177-1187
• 全文大小：3194 K

文摘

We detected temperature (salinity) decreases on the neutral density surfaces above the salinity minimum and increases below throughout the western North Pacific subtropical gyre (25N–40N, west of 170W) by comparing World Ocean Circulation Experiment (WOCE) hydrographic sections from the 1980s, 1990s, and 2000s. The temperature (salinity) changes around the salinity minimum were associated with an apparent oxygen utilization (AOU) increase, and could not be explained by an increase of the subpolar input. These property changes were due to a density decrease of the salinity minimum. Furthermore, similar changes in temperature (salinity) were detected along 165E as a 12-year trend from 1996 to 2007. This suggests that the changes evident in the comparison of the WOCE sections are the representative of changes at the intermediate depths in the last decade. This pattern was not detected in the eastern subtropical gyre (25N–40N, east of 170W) and along 47N, where the AOU increase due to ventilation reduction has been reported. Along 47N, changes in temperature, salinity and AOU from 1999 to 2007 were opposite to those from 1985 to 1999.