A new multi-scale modeling framework with an advanced higher-order turbulence closure

Description

Annual and seasonal mean state, diurnal cycle, and MJO-like variability in a new multi-scale modeling framework (MMF) are analyzed, in which the cloud processes are represented by a two-dimensional (2D) cloud-system resolving model (CRM) with an advanced higher-order turbulence closure (HOC) at each general circulation model (GCM) grid box. The Community Atmosphere Model (CAM3.5) is used as the host GCM, while the CRM is the system for atmospheric modeling (SAM). The results from the new MMF are compared with those from the MMF with a first-order turbulence closure implemented in SAM. The global distribution of low cloud amount and the representation of the middle-level clouds in mid-latitude storm track regions show substantial improvement compared with those from the old MMF. Some improvements can also be seen from the diurnal cycle and MJO-like variability.