Growing land-sea temperature contrast and the intensification of Arctic cyclones

Cyclones play an important role in the coupled dynamics of the Arctic climate system on a range of timescales. Modelling studies suggest that storminess will increase in the Arctic summer due to the enhanced land-sea thermal contrast along the Arctic coastline, in a region known as the Arctic Frontal Zone (AFZ). However, the climate models used in these studies are poor at reproducing the present-day Arctic summer cyclone climatology and so their projections of Arctic cyclones and related quantities, such as sea ice, may not be reliable. In this study we perform composite analysis of Arctic cyclone statistics using AFZ variability as an analogue for climate change. High AFZ years are characterised both by increased cyclone frequency and dynamical intensity, compared to low years. Importantly, the size of the response in this analogue suggests that GCMs may underestimate the response of Arctic cyclones to climate change, given a similar change in baroclinicity