Analysis of Polar Mesocyclonic Surface Turbulent Fluxes in the Arctic System Reanalysis (ASRv1) Dataset

At the polar latitudes, maritime mesocyclones form throughout the year, often near or embedded within cloud streets associated with massive cold air outbreaks. Such storms appear on the 100–1000 km horizontal scale. However, polar mesocyclones tend to exist on the lesser end of the horizontal scale. As a storm's size decreases, the likelihood that they will be well-represented in data also decreases. Underrepresentation of polar mesocyclones in reanalyses will affect climatological forecasts and research that utilize such data. Namely, the air-sea interactions associated with polar mesocyclones will be undercut, thereby impacting estimates of ocean circulation. Additionally, many reanalyses underestimate near-surface wind speeds, which is linked to but not exclusively dependent upon the problems associated with data resolution. Harsh polar conditions make regions of scientific interest unfavorable for in situ data collection, which compounds the aforementioned issues. This research examines the relatively new Arctic System Reanalysis (ASRv1) and its ability to represent three polar mesocyclonic systems of differing size. Should ASRv1 represent polar mesocyclones effectively, it could be a prime candidate in establishing an arctic atmospheric state for air-sea modeling. The product is compared to high-resolution Weather Research and Forecasting (WRF) model simulations, with ERA-Interim information providing the initial and boundary conditions. Simulation results are checked against available 10m equivalent neutral wind data from QuikSCAT to ensure that the model is producing reasonable atmospheric conditions. Comparisons are drawn for near-surface wind fields and surface turbulent fluxes to focus on ASRv1's depictions of air-sea interactions for polar mesocyclones. Differences betwixt ASRv1 and the WRF simulations are given with the likely explanations—physical, dynamical, and data-based (e.g., resolution, model options)—behind such differences.