Many factors are important in order for numerical models of the atmosphere to provide accurate forecasts. One of these is the fact that the state of the atmosphere at the initial time of the model must be adequately specified. A common and difficult problem is how to account for the redistribution of heat, momentum and moisture by weather phenomena that exist at initial model time (e.g. individual thunderstorms in mesoscale models). When such conditions are not specified adequately, numerical models tend to be inaccurate in the early stages of their forecast period. This is known as the "spin-up" problem. The Principal Investigator will pursue and extend earlier investigations using a new technique, known as non-local mixing, in the initialization process for regional (mesoscale) models. Both theoretical and numerical research will be used in the development and verification of appropriate model techniques using existing high resolution research data sets. If successful, the results from this study will be of great benefit for alleviating the "spin-up" problem in mesoscale models in the six to twelve hour time range.
