Analytical Initialization for Three-Dimensional Numerical Models

Abstract

A technique for generating analytical initial conditions for three-dimensional numerical models is presented. The technique combines trigonometric and other mathematical functions with meteorological constraints to construct an idealized atmosphere which exhibits commonly observed ?real? atmosphere structural characteristics. For example, pressure and thermal waves which slope with height, tropopause, low-level moist tongue, phase differences in pressure and thermal waves, and a jet maximum at the tropopause level are all generated by the simple system of equations. Examples of both mesoscale and synoptic-scale initial conditions are given, and results of integrating the mesoscale initial conditions in a three-dimensional model are shown. The initialization procedure is economical and flexible, and potential applications include testing weather modification sensitivity, finite-difference schemes, lateral boundary formulations, and various subgrid-scale parameterizations.