Two-Way Interactions between the Arctic and Mid-Latitudes Associated with a Wavy Jet Stream

Abstract:

Large-amplitude planetary waves in the eddy-driven jet stream may cause extreme weather in mid-latitudes, for example long-lasting cold spells in winter and heat waves in summer. Such extreme events in mid-latitudes have received a lot of attention, but much less studied are simultaneous anomalous events in the Arctic that occur in different parts of the same wavy jet stream and are governed by thermal advection from mid-latitudes. We analyse cases of high-amplitude waves in the jet stream, and compare their effects in the parts of the jet stream where Arctic air masses are advected towards mid-latitudes and mid-latitude air-masses are advected towards Arctic. We further compare the performance of numerical weather prediction models in the Arctic (northern Canada, Greenland, and Eurasian Arctic archipelago) and mid-latitude regions (U.S. East Coast, northwestern Europe, and eastern Asia) affected by the strong thermal advection.