Simulation of mass and moisture transport in a regional climate model of the Arctic

Realistic climate simulations require an understanding of the forcing mechanisms and scales required. In the Arctic, observational studies indicate both the prominence of a decadal time scale and the importance of surface heterogeneity at very small spatial scales. Simultaneously, these climate features place a substantial burden on modeling dynamics. Here, we assess the performance of two regional model configurations at high latitudes via the examination of atmospheric circulation variables. The first is a standard eulerian configuration that is currently implemented in a coupled atmosphere-ocean-sea ice climate model useful for high latitude simulations known as ARCSyM. The second is a semi-lagrangian adaptation of the model for kinematic and transport variables. Comparison of the two methods centers on the depictions of atmospheric circulation in comparison to observations and the resulting horizontal fluxes of mass and moisture over the Arctic domain. This study offers an appraisal of semi-lagrangian dynamics in comparison to current eulerian methods in high latitude regional climate simulations.