PNNL

Abstract

An unphysical checkerboard pattern has recently been identified in E3SM-MMF that is hypothesized to be associated with the trapping of cloud-scale variance in the embedded CRM due to the inability for cloud-scale fluctuations to be directly advected by the large-scale dynamics on the global grid. To address this issue, a method is presented for transporting CRM variance on the global grid of E3SM-MMF. Simulation results show that this method is effective at reducing the occurrence of checkerboard patterns in E3SM-MMF on a range of time scales, from days to years. This result is confirmed both subjectively through visual inspection and quantitatively with a previously developed pattern detection method. The use of CRM variance transport does not significantly alter the climate, although is does tend to reduce temporal variance on fields associated with convection on the global grid.