Comparison of Arctic Cyclones in CESM2 Large Ensemble and ERA5

Even as global climate models have improved in their representation of Arctic processes, capturing observed trends in certain Arctic processes, such as sea ice and Arctic cyclones (ACs), continues to prove difficult. The release of the CESM2 Large Ensemble data provides the opportunity to re-examine how these processes are represented in models. We hypothesize that there will be improvements from previous generations of climate models but still lack precision when compared to observations. We characterize ACs and Tropopause Polar Vortices (TPVs) in both CESM2 LE and ERA5 data. This is accomplished by applying a watershed method tracking algorithm to the model output, creating a dataset of AC and TPV cyclone tracks. We are then able to compare properties of those cyclones, such as genesis and lysis locations, lifetime, radius, and strength, to cyclones in reanalysis data and previous model studies generated by the same method.