Seminar by Prof. Tore Furevik from Bjerknes Centre for Climate Research
27 November 2018
10:00 — 11:00
I will discuss recent and ongoing works on the warming of the Arctic in boreal winter, most pronounced in the northern Barents and Kara Seas, and its linkages to east asian climate. Coinciding with Arctic surface warm anomalies in recent decades (i.e., 1997–2017), the Siberian high has been significantly intensified. The East Asian jet stream expanded westward, and an apparent Rossby wave has propagated from the Arctic to East Asia, suggesting an atmospheric teleconnection between midlatitudes and Arctic. In contrast, the corresponding midlatitude atmospheric circulation anomalies concurrent with Arctic surface warm anomalies during 1979–1996 were barely statistically significant. We hypothesize that mid-tropospheric warming plays a crucial role for the linkages between midlatitudes and Arctic in boreal winter. Multi-model simulations support this view, and point to the effect of internal atmospheric variability in the strengths of the midlatitude – Arctic linkages.