Temperature of North Pacific subtropical mode water over the past 100 years: ocean warming and decadal-scale variations

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K17756
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: Tohoku University
• Principal Investigator: Shusaku Sugimoto 東北大学, 学際科学フロンティア研究所, 助教 (50547320)
• Research Collaborator: FUKUI SHIN 東北大学, 大学院理学研究科, 研究員
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 亜熱帯モード水 / 海洋温暖化 / 10年規模変動 / CMIP5 / 再解析データ / 領域大気モデル / 大気海洋相互作用

Outline of Final Research Achievements

I investigated long-term behavior of the subtropical mode water (STMW) in the North Pacific, using historical temperature profiles from academic institutions from around the world. I showed that the STMW has marked warmed over the past one hundred years, the warming rate of which is estimated as 1.13 ± 0.27 °C per century. The STMW temperature has significant decadal (about 10 year) variations, which is formed by a vertical entrainment process associated with a deepening of mixed layer depth during winter. By conducting atmospheric model experiments, I found that significant warming due to the eddies with the STMW extend not only into the near-surface atmosphere but also into the high altitude, reaching about 4000m.

Free Research Field

海洋物理学