The experimental modification of a barotropic numerical prediction model

Abstract

There were two objectives in the experiments performed on the barotropic model. One was to correct the lag of the troughs and ridges noted in the barotropic model by the Naval Weather Research Facility, and the other was to introduce a baroclinic development term, The approach to these problems was one which could be incorporated into the Fleet Numerical Weather Facility model with ease. Included herein are the theoretical development of the numerical model, a comparison with the FNWF model and charts illustrative of the results with various values of the pertinent parameters for 24 and 48 hours. It was observed that the development term causes selective development of lows and highs; but when overdone, spurious short waves are formed which, however, do not basically change the major wave location. It was also observed that the function of latitude used here to correct the lag in the horizontal advection of vorticity, resulted in greatly improved movement of troughs and ridges from 30 degrees to 60 degrees of latitude, but could be further refined to produce even better results.