Quantifying and investigating the causes of freshwater content change in the Southern Ocean overturning

2016 Fiscal Year Final Research Report

• Project/Area Number: 25281001
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Hokkaido University
• Principal Investigator: AOKI Shigeru 北海道大学, 低温科学研究所, 准教授 (80281583)
• Co-Investigator(Kenkyū-buntansha): 深町 康 北海道大学, 低温科学研究所, 准教授 (20250508)
• Project Period (FY): 2013-04-01 – 2017-03-31
• Keywords: 環境変動 / 環境分析 / 南極海 / 淡水循環 / 酸素安定同位体比

Outline of Final Research Achievements

The Antarctic continental shelf is an important region in that it provides very dense water, which is one of the sources of Antarctic Bottom Water (AABW) that fills the global abyssal ocean. Recently freshening of AABW is reported and the causes are suspected to be on the Antarctic margin. This study aims to clarify the changes in oceanic properties in the Antarctic margin, especially based on in-situ hydrographic surveys including a noble tracer to detect continental ice melt component. For the Ross Sea shelf, the observed freshening corresponded to the basal warming in the West Antarctic shelf. For Adelie Depression off Adelie Land coast, both sea ice production and land-ice melt could change the shelf water properties, which can affect the properties of bottom water. Hence it was proposed that ice condition changes can affect the overturning circulation originated in the south.

Free Research Field

極域海洋学