Strategic Research Target③

Evaluation of the impacts of Arctic change on weather and climate in Japan, marine ecosystems and fisheries

③-a Evaluation of the impacts of Arctic change on weather and climate in Japan
Principal Investigator : Jinro Ukita (Niigata University)

Arctic teleconnection

No part of the Earth's climate system is independent from the rest. The weather and climate in Japan are not exceptions. Scorching summers and severe winters in Japan are sometimes attributed to influences from remote places. Our weather and climate are linked to El Niño and La Niña conditions, which are coupled oceanic and atmospheric phenomena centered over the tropical Pacific. In recent years we are beginning to understand that the Arctic also exerts influences by changing atmospheric circulation. This is referred to as "atmospheric teleconnection". In facing the rapid Arctic changes such as sea ice reduction, warming in the Arctic Ocean and the surrounding continents, and other accompanying changes in the hydrology and biosphere, our primary task here is to better understand physical and chemical mechanisms of this Arctic teleconnection, which results from an interplay of many different processes in clouds, aerosols, radiation and circulation. Our previous studies hint that a meandering of the westerly jet stream and other circulation anomalies such as strong Siberia and Okhotsk high pressure systems are relevant to the Arctic teleconnection. Here we seek detailed explanations about the underlying processes involved and evaluate their impacts on the weather and climate in Japan.

Expected results

By gaining a better understanding of the underlying processes of teleconnection from the Arctic, we provide both qualitative and quantitative assessment on the impacts of the Arctic change on the weather and climate in Japan.

③-b Evaluation of the impacts of Arctic change on marine ecosystems and fisheries
Principal Investigator : Takashi Kikuchi (Japan Agency for Marine-Earth Science and Technology)

Is the decrease in sea ice favourable or unfavourable for the Arctic marine ecosystem and fisheries?

The decrease in the sea ice causes a change in the characteristics of the seawater in the Arctic Ocean, such as temperature, salinity, and nutrients as well as ocean currents. It also affects the lives of marine microbes, planktons, fishes, and other mammals. Marine fisheries resources such as cod, salmon and crab are no exception. This raises the questions: Is the decrease in sea ice favourable or unfavourable for Arctic marine ecosystems and fisheries? How does sea ice variability, i.e., ice melting/formation, ice motion, seasonal cycle, and recent inter-annually rapid decrease, affect the Arctic Ocean environments from physical, chemical and biological points of view? To achieve strategic research target ③-b: Evaluation of the impacts of Arctic change on marine ecosystem and fisheries, we initiate the following research project.

(6) Ecosystem studies on the Arctic Ocean declining sea ice

The purpose of this project is to clarify and predict the influences of sea ice reduction in the Arctic Ocean on marine ecosystem and fisheries resources. For this purposes, we will conduct field observations in the Pacific side of the Arctic Ocean, satellite monitoring on sea ice and marine environments, and numerical simulations to acquire a detailed understanding of on-going environmental changes and future conditions. Not only biological but also physical and chemical processes are involved in the Arctic environmental changes caused by the recent sea ice reduction. Therefore, this project will pay particular attention to linking multidisciplinary studies on the Arctic Ocean, i.e., physical, chemical, and biological oceanography.

Expected outcomes

Field measurement during the project and analyses using historical and observational data can reveal on-going changes in the Arctic Ocean environment. Important multidisciplinary processes which cause such environmental changes are also clarified. Development of marine ecosystem models for the Arctic Ocean can bring to light detailed information on on-going environmental changes and may help in predicting future changes in fisheries resources and population sizes.