Research Project (7)

Projection of sea ice distribution and Arctic sea routes

Principal Investigator: Koji Shimada (Tokyo University of Marine Science and Technology)

Sub-Research Project a

Changes in the Arctic Ocean and mechanisms of catastrophic reduction of Arctic sea ice

Principal Investigator: Koji Shimada (Tokyo University of Marine Science and Technology)

Outline

Recently, the reduction rate of Arctic sea ice in summer is greater than the rate of increase in global mean surface temperature. This indicates that there is a positive feedback mechanism in the Arctic climate system, accelerating the reduction in the sea ice. Our goal is to get a better understanding of this mechanism. Therefore, we have set up a systematic ocean observation system on the Pacific side of the Arctic Ocean, where a disproportionately large degree of reduction in sea ice has been observed. We plan to use several icebreakers to measure water temperature and salinity, take water samples, and deploy moored instruments. In addition, we are also utilizing satellite data, to get a better understanding of the dynamics of heat and salinity in the atmosphere- ice-ocean systems and their impact on sea ice reduction. Based on these measurements, we plan to clarify the dynamics of a) ocean circulation, b) the amount of heat stored in the ocean, and c) the reservoir of fresh water in conjunction with changes in sea ice, and thereby contribute to the achievement of strategic research target ④ Projection of sea ice distribution and Arctic sea routes.

Poisitive feedback driving on-going reduction of Arctic sea ice without rebound
(Photo: Eri Yoshizawa, Tokyo University of Marine Science and Technology)