How Well Do Modern Atmospheric Reanalyses Represent Extreme Precipitation Events in the Baffin Bay Region?

Precipitation is often considered one of the variables with the highest uncertainty in climate modeling due to low spatial autocorrelation, difficulty obtaining accurate measurements, and high dependence on model setup. Atmospheric reanalyses are popular tools for climate studies, particularly in data-sparse regions where observations are difficult to obtain, such as the Arctic. Modern reanalyses are generally effective at reproducing Arctic climates, but their performance in recreating extreme precipitation events is not as well known. Since climate change is expected to increase the frequency of extreme events, representing them accurately in reanalyses and models is vitally important. The Baffin Bay region is particularly vulnerable to these changes because intense precipitation events often account for a considerable portion of annual precipitation in the region. Because of this, small changes in extremes can cause more substantial regional hydrological impacts, which can have adverse effects on local Indigenous communities and the surface mass balance of glaciers and ice caps.In this study, the ECMWF Reanalysis Version 5 (ERA5), NASAs Modern-Era Retrospective analysis for Research and Applications Version 2 (MERRA-2), and NCEP Climate Forecast System (CFSR) are compared to surface station observations and gridded output from the Global Precipitation Climatology Project (GPCP) to investigate the representation of extreme precipitation events in the Eastern Canadian Arctic and Western Greenland. Here, an extreme event is defined as a day when precipitation is in the top 5% of values for that location. Extreme event frequency and intensity are explored in both an annual and seasonal context. Similarities and differences between the products are explored through statistical analysis and case studies.