[A-CG31] Climate Variability and Predictability on Subseasonal to Centennial Timescales

[ACG31-09] Driver of the recent decadal surface warming trend over northeastern Canada and Greenland

*小川 史明¹、Noel S. Keenlyside^2,3、Nour-Eddine Omrani² (1.東京大学先端科学技術研究センター、2.ベルゲン大学地球物理研究所、3.ナンセン環境研究所)

キーワード：北極域での地域的な温暖化増幅、近隣の影響、遠隔影響、複数モデル

North-eastern Canada and western Greenland (NCWG) regions show a local maximum of the Arctic warming amplification trend over recent decades. Unlike the short seasonal persistence of the warming over most Arctic regions, the NCWG warming trend is persistent throughout the year. It suggests that warming processes over the NCWG and other Arctic regions differ. NCWG warming has been explained by the remote influence of tropical SST change. However, the NCWG warming could have also been influenced by local SST and sea-ice changes in addition to the Arctic amplification of the greenhouse effect, where the relative importance for the NCWG warming has never been evaluated. Using a dataset from multi-model coordinated AGCM simulations as well as reanalysis and observed data sets, here we show that the observed recent multi-decadal warming over the NCWG region is largely driven by the local SST and sea-ice changes associated with Atlantic multi-decadal variability. The greenhouse effect has also contributed to the melting of local sea ice and amplified warming, while the remote influence from tropical SST change is not predominant.