Cryospheric and Polar Processes Seminar
"The Influence of the Arctic Frontal Zone on Summer Cyclone Activity Today and in the Future"
The Arctic frontal zone (AFZ) is a narrow band of strong horizontal temperature gradients that develops along the Arctic Ocean coastline in summer in response to differential heating of the atmosphere over adjacent land and ocean surfaces. Past research has linked baroclinicity within the AFZ to summer Arctic cyclone development, especially by intensifying storms that migrate northward from the Eurasian continent. This study uses the Community Earth System Model Large Ensemble and an advanced cyclone detection and tracking algorithm to assess how the AFZ, Arctic cyclone activity, and the relationship between them respond to a global warming scenario. Under a strong warming scenario, the AFZ remains a significant cyclone intensifier, and changes to the AFZ are largely restricted to June. Earlier snow melt leads to strengthening of the AFZ in June, and this strengthening is accompanied by enhanced cyclogenesis along the east Siberian coast, but no change is observed for overall cyclone frequency and intensity in the Arctic. However, simultaneous changes to sub-polar storm tracks impact Arctic cyclone activity in all summer months, sometimes in opposition to the impact of the summer AFZ.