Exploration of deep mesoscale variabiilty by high-density mooring observation

2017 Fiscal Year Final Research Report

• Project/Area Number: 26610149
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Meteorology/Physical oceanography/Hydrology
• Research Institution: The University of Tokyo
• Principal Investigator: Oka Eitarou 東京大学, 大気海洋研究所, 准教授 (60360749)
• Co-Investigator(Renkei-kenkyūsha): YANAGIMOTO Daigo 東京大学, 大気海洋研究所, 助教 (40260517) ; FUJIO Shinzo 東京大学, 大気海洋研究所, 准教授 (00242173) ; HASUMI Hiroyasu 東京大学, 大気海洋研究所, 教授 (40311641)
• Research Collaborator: MIYAMOTO Masatoshi
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 海洋深層 / 中規模変動 / 係留観測 / 地形性ロスビー波

Outline of Final Research Achievements

To clarify the characteristics and mechanism of mesoscale variability in deep layers of the ocean, we conducted high-resolution mooring observation around Station B (30N, 147E) from May 2014 to October 2015. We recovered seven out of nine moorings deployed in a 3x3 shape, and analyzed the obtained data together with mooring observation data in the 1970-80s around St. B as well as output from an eddy-resolving ocean general circulation model. At Station B, mesoscale variabilities with a period of about 60 and 170 days were propagating northwestward and west-southwestward, respectively as plane waves. Based on the estimated wave number vector and vertical structure, these variabilities were judged to be topographic Rossby waves originated in the Kuroshio Extension region and the Shatsky rise.

Free Research Field

海洋物理学