How Will the Summer Arctic Frontal Zone and its Influence on Arctic Cyclones Respond to a Warming Climate?

A persistent question regarding the Arctic's future is how Arctic cyclone development will respond to a changing climate. This question has yet to be considered in the context of an important regional feature known as the Arctic Frontal Zone (AFZ). The AFZ is a narrow baroclinic zone stretching along the Arctic coastline that develops each summer in response to differential heating of the atmosphere over the warm land and cold ocean/ice surfaces. Past research has established the AFZ as an important factor in Arctic cyclone development. The stronger the AFZ temperature gradients, the more summer cyclones intensify as they pass over the Arctic coastline, leading to stronger storms providing more precipitation for the Arctic Ocean. However, development of the AFZ each summer is influenced by the timing of snow melt on the continents and sea ice retreat in the ocean, both of which are projected to change dramatically through the 21st century. In this study we utilize the Community Earth System Model Large Ensemble (CESM-LE) to project how the seasonal development and peak strength of AFZ is likely to change between the periods 1990-2005 and 2071-2080 under a strong global warming scenario (Representative Concentration Pathway RCP 8.5). We then use a cyclone detection and tracking algorithm to assess how the response of the AFZ to global warming will in turn affect the formation and development of Arctic cyclones.