Improved simulations of atmospheric river climatology and variability in high-resolution CESM

Their variability has been linked to various climate modes, such as El Nino/Southern Oscillation, Pacific Decadal Oscillation, and Pacific-North America pattern. Understanding and improving simulation of this linkage can provide the potential to predict ARs at subseasonal-to-decadal timescales.

Up to now, the extent to which climate model simulations of ARs are dependent on model resolutions has not been fully assessed. Here, we compare and evaluate ARs in a pair of high-resolution (HR) and a low-resolution (LR) Community Earth System Model (CESM) simulations against the observations. The results show that within this CESM framework, climatological AR strength and associated precipitation are severely underestimated by LR compared to the observations, and their relationships with major modes of climate variability are also poorly reproduced.