[A-CG42] Science in the Arctic Region

[ACG42-05] Future changes of year-to-year variability in surface air temperature in the Arctic and accessibility of the northern sea route under various Shared-Socioeconomic Pathways

*Takuro Aizawa^1,2, Naga Oshima², Seiji Yukimoto², Yusuke Ushijima² (1.National Institute of Polar Research, 2.Meteorological Research Institute)

Keywords:Arctic, Climate model, Surface air temperature, Year-to-year variability, Future change, Northern sea route

Changes in the regions covered by sea ice have extensive impacts not only on the Arctic climate change or the Arctic marine ecosystem, but also on various aspects of human activities and socio-economic endeavors. However, climate model projections of future Arctic sea ice areas are still challenging. We conducted the single model analysis based on Meteorological Research Institute Earth System Model version 2.0 (MRI-ESM2.0) and found that, as global warming progresses in the future, it is expected that the year-to-year variability in surface air temperatures over the regions covered by sea ice in the present-day will exhibit a slight increase in the summer, but notably decrease during autumn to spring. Moreover, we found that, even when fully considering the year-to-year variability of sea ice concentrations, MRI-ESM2.0 forecasts that by the early 2030s, the vessels will be able to safely navigate along the northern coast of the Eurasian Continent in at least September. The accessibility of the northern sea route is projected to increase in the future in scenarios which economic development relies on fossil fuels or which regional fragmentation intensifies. We also found that the stabilization of the Arctic shipping route is important for a decrease in the year-to-year variability in surface air temperature.