Formulation and evaluation of a nonhydrostatic vorticity-mode mesoscale model
The present work defines applicability limits for some commonly made assumptions in mesoscale atmospheric models. The first part reviews the dynamic and thermodynamic equations governing atmospheric flows, and identifies the various simplifications required for their practical use in numerical models. A scale analysis technique is used to discuss qualitatively these simplifications. Atmospheric space scales, flow assumptions, governing equations, and resulting motions are organised into a hierarchy that is used to categorise some of the contemporaneous mesoscale models. In the second part, a nonhydrostatic vorticity mesoscale model is formulated that has the principal characteristic of only requiring two vorticity components (horizontal ones). Equations and boundary conditions are first expressed in a Cartesian coordinate system, and are next transformed to account for complex topography. The objective of the third part is to evaluate the model. An idealised valley-plain configuration is used to evaluate model aptitudes in reproducing three-dimensional flow circulations while comparisons with field campaign measurements are briefly discussed.
Bibliographic Reference: EUR 16141 EN (1995) 151 pp.
Availability: Available from Joint Research Centre, Public Relations Office, I-21020 Ispra (Va.) (IT)
Record Number: 199510350 / Last updated on: 1995-03-21
Original language: en
Available languages: en