Accession Number : ADA113135

Title :   Optimal Spatial Representations for Numerical Weather Prediction Models Based on Normal Mode Analyses.

Descriptive Note : Final rept. Jun 78-Sep 81,

Corporate Author : MARYLAND UNIV COLLEGE PARK DEPT OF METEOROLOGY

Personal Author(s) : Baer,F ; Sheu,P -J

PDF Url : ADA113135

Report Date : Jan 1982

Pagination or Media Count : 90

Abstract : A method is devised to determine the computational errors associated with space truncation in numerical weather prediction models. This method is based on evaluating the normal modes of the linearized form of the prediction model. The modes are separated into their physical and computational parts. A special procedure has been devised to make this separation definitive. It is the computational modes which give rise to computational errors. To reduce the impact of these modes, their contributions are filtered out of the initial data used to begin a forecast. Although computational mode amplitude will develop during integration because of nonlinearity, the impact of the computational errors can be controlled by the filtering technique described here. If initial filtering is not adequate, additional filtering may be applied periodically throughout the integration period. (Author)

Descriptors :   *WEATHER FORECASTING, *MATHEMATICAL MODELS, *BOUNDARY VALUE PROBLEMS, SPATIAL DISTRIBUTION, LIMITATIONS, VERTICAL ORIENTATION, HORIZONTAL ORIENTATION, MATHEMATICAL FILTERS, TRANSFORMATIONS(MATHEMATICS), NUMERICAL INTEGRATION, COMPUTATIONS, ERRORS, FINITE DIFFERENCE THEORY, ATMOSPHERE MODELS, THERMODYNAMICS

Subject Categories : Meteorology
      Numerical Mathematics

Distribution Statement : APPROVED FOR PUBLIC RELEASE