Arctic storm simulation with the Arctic MM5 model: performance validation

A meso-scale modeling system based on the PSU/NCAR MM5 model, named as the Arctic MM5 model, has been developed. The Arctic MM5 model includes a version of the land surface model NOAH-LSM (e.g., Mitchell et.al, 2002), a thermodynamic sea ice model (Zhang and Zhang, 2001) and an ocean mixed layer model (MLM; Kantha and Clayson, 1994) to include the interactions between the sea ice, ocean and atmosphere.

Several studies on the cyclone frequency and intensity (e.g., Walsh et.al,1996, McCabe et.al, 2001) suggest that a significant increase of high latitude cyclone frequency, associated with the northward shift of storm tracks, is a regional trend for the Arctic under conditions of global warming. This suggests further that interactions between cyclonic systems and the larger scale circulation may well play an important role in the evolution of a global warming scenario in high latitudes. As such, it is necessary to investigate the fidelity of any model's simulation of Arctic storms and their interactions with the larger scale flow.

In this study, we examine the performance of the Arctic MM5 model on the simulation of Arctic storms via two case study analyses and use these analyses to suggest areas of model improvement needed to improve the depiction of storms and storm-flow interactions.