Assessment of summer precipitation on James Ross Island, Antarctic Peninsula based on the WRF model output and in-situ observations

Summer precipitation in the polar regions is important for many aspects of local environment. Examples include moss and lichens growth, snow-melt runoff, or snow accumulation on glaciers. However, precipitation observations, especially in Antarctica, are very limited due to complicated logistics and  frequent blowing-snow transport and sublimation processes. One of the novel methods how to improve the in-situ precipitation estimates is an application of a very‑high‑resolution numerical atmospheric model. A state-of-the-art, Weather Research and Forecasting (WRF) model, was run for two summer months in early 2022 over northern Antarctic Peninsula and James Ross Island, respectively. Model setup included 300 m horizontal resolution, 65 vertical levels and a new 3D TKE scheme which is especially suitable for subkilometer-scale WRF simulations. James Ross Island was selected because of availability of in-situ observations at proximity of the Johann Gregor Mendel Czech Antarctic Station. The observations were conducted by a Thies laser precipitation monitor (disdrometer) providing precipitation data at 1-minute resolution. Summer precipitation from the Thies measuring system and manual rain gauge observation was investigated in terms of duration, intensity, and phase (liquid/solid) and compared with corresponding WRF variables. In case of snow accumulation on the ground surface, snow height from the model output was compared with a sonic distance sensor data (Judd Communications). The influence of atmospheric circulation on heavy summer snowfalls was analyzed to show both the regional synoptic patterns and local (orographic) atmospheric processes. Finally, the ability of the WRF model to provide accurate and reliable precipitation records for other applications, e. g. snowpack storage and snowmelt-runoff modelling, was assessed.