Trends and spatial variation in rain-on-snow events over the Arctic Ocean during the early melt season

Abstract. Rain-on-snow (ROS) events can accelerate the surface ablation of sea ice, thus greatly influencing ice–albedo feedback. However, variability ROS over Arctic Ocean is poorly understood due to limited historical station data in this region. In study early melt season were investigated based on four widely used reanalysis products (ERA-Interim, JRA-55, MERRA, and ERA5) conjunction with available observations at coastal stations. The performance representing timing phase change precipitation was assessed. Our results show that ERA-Interim better represents onset date spring, ERA5 associated events. All reanalyses indicate event has shifted earlier dates recent decades (with maximum trends up ?4 ?6 d per decade some regions ERA-Interim) ice Pacific sector most Eurasian marginal seas correlated shift. There been a clear transition from solid liquid precipitation, leading more although large discrepancies found between different products. ERA5, shift during directly contributed reduction spring snow depth by than ?0.5 cm averaged since 1980, largest contribution (about ?2.0 decade) Kara–Barents Canadian Archipelago.