Characteristics of High-Latitude Climate and Cloud Simulation in Community Atmospheric Model Version 6 (CAM6)

Many global climate models (GCMs) have difficulty in simulating variabilities over high northern latitudes. One of the main reasons is inability GCMs to simulate proper cloud fraction and amount liquid-containing region. This study assessed impact simulation latitudes by comparing long-term parallel simulations Community Atmosphere Model version 6 (CAM6) CAM5, previous version. The results show that CAM6 exhibits a considerable improvement Arctic, especially reducing cold bias CAM5 throughout year. Over sub-Arctic region, however, produces an excessive summer warm winter compared observation, which closely related overestimation liquid. In summer, tends alleviate due increase downward longwave radiation latitudes, while causing blocking shortwave land area. winter, when there little incidence radiation, increases alleviates Arctic but induces land. cloudiness could weaken high-latitude internal variability, exacerbating deteriorating variability trend