Impact of model resolution on the response of Arctic hydrological cycle to climate warming

Abstract

Abstract The Arctic hydrological cycle is amplified due to sea ice decline, which can influence warming and precipitation over land. However, the response of the terrestrial hydrological cycle, in climate models, to Arctic warming may be dependent on model spatial resolution. Two spatial resolutions of the same CMIP6 physical climate model, HadGEM3-GC3.1, show that the hydrological storage terms and precipitation behave identically with warming. The exception is snow volume which declines faster at low spatial resolution. Surface elevations are smoothed for low resolution, with the result that orographically induced precipitation is lower than at higher resolution. As a consequence, low resolution models will likely overestimate the rate of snow decline with warming compared with higher resolution models. Thus, caution is advised when using low resolution climate models for regional snow impact studies, and with mixed resolution models for climate model inter-comparisons,