Dynamical Processes in the Arctic Atmosphere

Abstract

The scales of dynamical processes in the Arctic atmosphere range from turbulence in the atmospheric boundary layer (ABL) via interactive mesoscale processes, such as orographic flows and Polar lows, to synoptic-scale cyclones, and further to hemispherical-scale circulations characterized by the Polar front jet stream and planetary waves. Specific boundary conditions for tropospheric dynamics in the Arctic include (a) sea ice and snow, which strongly affect the surface energy budget, (b) large transports of heat and moisture from lower-latitudes, and (c) the wintertime stratospheric Polar vortex, which has a large impact on tropospheric large-scale circulation and synoptic-scale cyclones. Knowledge on dynamics of the Arctic atmosphere is advancing but, compared to mid- and low-latitudes, still limited due to lack of process-level observations from the Arctic. The dynamics of the Arctic atmosphere poses a challenge for numerical weather prediction (NWP) and climate models, in particular in the case of ABL, orographic flows, Polar lows, and troposphere-stratosphere coupling. More research is also needed to better understand how the atmospheric dynamics affects and is affected by climate warming.