Analysis of recent melt season cyclones in a warming Pacific Arctic

As the Arctic continues to warm and melt, high-latitude marine and coastal environments are increasingly vulnerable to transient weather systems. This is evident in the Pacific Arctic where sea ice has shown particular sensitivity to synoptic forcing during the last fifteen years, as observed within extreme melt seasons in 2008, 2012, 2016, and 2019. Inversely, there is uncertainty as to what extent such systems are modified by underlying changes in the sea ice and upper-ocean conditions. Our analyses focus on identifying Pacific Arctic cyclones, derived by Lagrangian and Eulerian approaches applied to atmospheric reanalysis data, and examining their melt season frequency, intensity, and duration variability and change from 1948-2021. Emphasis is placed on these cyclone characteristics' anomalies during recent years and their lead-lag associations with underlying sea ice and near-surface ocean observations. Utilizing WindBorne radiosonde retrievals from an ONR field campaign, we also provide a case study of a summer 2021 cyclone by examining upper-air profiles as the system traveled over the relatively warm Pacific Arctic waters and sparse ice cover close to the Beaufort Sea coast. Such in situ analyses captured within this area of rapid ice decline are valuable to understand how changing Arctic boundary conditions may interact with synoptic systems.