A basic study on evaluation of effects on the global deep circulation caused by freshening of Antarctic surface water

2014 Fiscal Year Final Research Report

• Project/Area Number: 23310003
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Tokyo University of Marine Science and Technology
• Principal Investigator: KITADE YUJIRO 東京海洋大学, 海洋科学技術研究科, 准教授 (50281001)
• Co-Investigator(Kenkyū-buntansha): TAMURA Takeshi 国立極地研究所, 助教 (40451413) ; MIZOBATA Kohei 東京海洋大学, 大学院海洋科学技術研究科, 助教 (80586058)
• Co-Investigator(Renkei-kenkyūsha): SHIMADA Keishi 東京海洋大学, 観測支援センター, 博士研究員
• Research Collaborator: 青木 茂 北海道大学, 低温科学研究所, 准教授 ; 平野 大輔 国立極地研究所, 博士研究員 ; 芦田 将成 東京海洋大学, 大学院海洋科学技術研究科 ; 鈴木 萌 東京海洋大学, 大学院海洋科学技術研究科 ; 白井 優 東京海洋大学, 大学院海洋科学技術研究科
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 海洋科学 / 極域環境 / 環境変動 / 深層循環 / 南極底層水 / 海面塩分

Outline of Final Research Achievements

Freshening of Antarctic Bottom Water (AABW) associated with freshening of sea surface water has been reported in recent years. In order to evaluate the effects of freshening of AABW to the Global deep circulation, hydrographic observations, long term mooring observations and turbulence measurements were carried out around 110 E and 140 E in January of 2012 to 2015. We found Bottom Water originating from the Vincennes Bay Polynya (VBBW) in the first time. Our observation also showed that the VBBW has spread into the upper part of AABW in Australia-Antarctica Basin. Freshening of Bottom water was also indicated off the Vincennes Bay region. Especially, the data obtained in January of 2014 showed that the VBBW has a potential to sink down to the ocean floor when the water density of surrounding AABW was reduced by freshening and warming.

Free Research Field

海洋物理学