Turbulence Parameterizations for Convective Boundary Layers in High-Resolution Mesoscale Models
Abstract
Several issues associated with grid resolution and the sub-grid scale (SGS) parameterizations in a mesoscale model are addressed in this study. Of particular concern is related to increasingly high-resolution mesoscale atmospheric numerical models, in that sub-grid scale parameterization of atmospheric processes becomes unclear when the grid resolution becomes comparable to the length scale of the phenomenon. These issues are studied through the careful analysis of in situ observations and mesoscale model testing. In this study, we perform observational analysis to better understand the scales of turbulence in various environmental conditions. We then explore the capability of the U.S. Navy's current Coupled Ocean-atmosphere Mesoscale Prediction System (COAMPS(trademark)), using a case study of boundary layer roll vortices in cold air outbreak conditions over the Japan/East Sea. We analyze the model's ability to perform accurately within the resolvable scales and to accurately represent the boundary layer turbulence mixing when the resolution is high. Based on results from the above analysis, we modify the existing parameterizations towards more realistic representations of the turbulent processes over a relatively wide range of grid resolution, and test this modification within COAMPS(trademark).
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2003
- Accession Number
- ADA420654
Entities
People
- Michelle K. Whisenhant
Organizations
- Naval Postgraduate School