High-resolution regional climate model validation and permafrost simulation for the East European Russian Arctic

A 15-year-long, 16 km horizontal resolution, present-day climate simulation has been conducted with the HIRHAM4 regional climate model. The model has been forced by the European Centre for Medium-Range Weather Forecasts reanalyses at the lateral boundary and over sea by sea surface temperature and sea ice concentrations from the same source. The model domain is centered over the European part of Arctic Russia focusing on the Usa River basin near the Ural Mountains. It is demonstrated that with this fine mesh, the model simulates the annual course and interannual variability in temperature and precipitation quite realistically. Furthermore the model captures the timing of permanent snow cover very accurately with less than 1-week discrepancy in both autumn and spring. An interpretation of modeled subsurface layer temperatures in terms of mean annual temperature and a "frost index" reveals that the model captures present-day regional permafrost patterns to a high degree of accuracy.