National Center for Atmospheric Research
Mesoscale and Microscale Meteorology
With the rapid increase in computer power, non-hydrostatic high-resolution models are becoming increasingly important not just for research but also for climate predictions and weather forecasting. Worldwide, numerous meteorological centers are now developing kilometer-grid global cloud-resolving models (CRMs). While many of these efforts are devoted to building dynamical cores, my research focuses on the analysis and parameterization of the unknown subgrid-scale (SGS) motions in CRMs.
I will first discuss issues with CRMs based on a benchmark large-eddy simulation (LES) of a tropical deep convection system using 10^9 gridpoints. This Giga-LES covers a domain of 204.8 km x 204.8 km x 27 km over the tropical ocean with a horizontal grid mesh of 100 m. The simulation captures a wide range of scales, from mesoscale eddies down to turbulent motions, and provides a key benchmark to study SGS motions in CRMs. I will show that a significant fraction of the vertical transport is carried by motions smaller than a typical CRM grid mesh.
The second part of my talk discusses the use of the Giga-LES in developing SGS parameterizations for CRMs. The Giga-LES flow fields are partitioned into CRM resolved and CRM SGS components and their relationship is investigated. I will show that conventional SGS-flux schemes are inadequate in representing SGS transport processes in CRMs.
This seminar will be recorded and available via webcast at:
Thursday, 14 November 2013, 3:30 PM
Refreshments 3:15 PM
3450 Mitchell Lane
Bldg 2 Main Auditorium, Room 1022