Objective Numerical Prediction Out to Six Days Using the Primitive Equation Model-A Test Case


Book Description

This report is a brief summary of the results of a test case study using the primitive equations to make numerical predictions out to six days after the initial time. Daily and select 5-day mean chart of 500-, 700-, and 1000-mb height and 1000 to 500- and 1000 to 700-mb thickness, along with their departures from normal, where produced directly from the model. For comparison, the barotropic 500-mb forecast heights were also obtained, and both primitive and barotropic forecasts were compared with the observed heights and thicknesses.



















Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.










Noise Analysis of a Limited-area Fine-mesh Prediction Model


Book Description

"A diagnostic study of the mechanism responsible for producing high wavenumber oscillations (noise)in the numerical solution of the nonlinear equations governing a free surface, barotropic, atmospheric model is reported. The oscillations are identified as predominantly the result of the lattice of the difference equations and the boundary conditions employed to specified the solution. The analytic methods employed involved the use of space and time sections of the numerical solutions to provide a set of hypotheses. These are tested utilizing a one-dimensional linear analog of the model equations. The solution of the linear equations is obtained analytically, by the method of characteristics, and numerically. Several possibilities for removing the noise are suggested. Some improvement is demonstrated when the suggested methods are used in the linear one-dimensional analog.




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