10.5
Super-parameterization of roll vortices in tropical cyclone models
PAPER WITHDRAWN
Isaac Ginis, Univ. of Rhode Island, Narragansett, RI; and A. Khain
The primary effects of roll vortices on the boundary layer (BL) fluxes are inherently non-local and non-gradient and hence cannot be captured by standard parameterizations used in present tropical cyclone models. A new approach to the parameterization of roll vortices in the BL will be discussed. It resembles a recently emerged approach called �super-parameterization� of complex cloud processes in a GCM. The idea is to use a 2D cloud-resolving model in each column of a large-scale model to explicitly represent small-scale and mesoscale processes and interactions among them. Similarly, our method can be called super-parameterization of roll vortices in the BL, which includes a 2D high-resolution non-hydrostatic model that explicitly resolves roll vortices coupled with a 3D system of equations representing the large-scale (mesoscale) flow. The idea is based on a scale separation with the following assumptions: a) roll vortices and the large-scale flow have remarkably different horizontal scales across the background (mean) flow, and b) roll vortices are realized in the form of �2D� rolls aligned with the background (mean) wind. These differences in the characteristic spatial scales allow for the decomposition of the full 3-D equation system, representing a tropical cyclone model, into two coupled equation systems for the mean large-scale (or mesoscale) flow and convective scale motions (roll vortices) in it. An example of the application of this approach to a tropical cyclone model will be presented.
Session 10, Air-Sea Interaction in Tropical Cyclones and Intraseasonal Oscillations
Thursday, 2 February 2006, 1:30 PM-5:30 PM, A309
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