The Use of Dynamic Grid Adaptation Technique in Tropical Storm Prediction

The threat to life and property from Topical Cyclones/Hurricanes (referred to hereafter as TCs) is well recognized by the scientific community and the general public. The study of TCs has been the subject of many numerical studies in the past three decades. In despite of these studies, the models used in numerical weather prediction (NWP) still remain scale-specific. There is a general consensus that the simulation of the atmosphere at all relevant scales together is an intractable problem. One obvious method to improve the prediction of NWP models is to enhance the spatial grid resolution. However, introducing fine spatial resolution throughout a simulation domain is not always practical. One alternative is then to develop methodologies capable of providing local refinement in certain key region to resolve the smallest scales of interest (e.g., convection). More recently, a relatively new unstructured adaptive grid technique is applied to the atmospheric problems. These recent studies have been shown that the primary benefit of the unstructured grid technique lies in its ability to smoothly transition from high resolution where needed to low resolution elsewhere. A study involving numerical simulations of the most recent hurricanes (e.g., Frances, Katrina, Rita) will be presented in the conference to show the use of unstructured adaptive grid technique to characterize and better predict the hurricane's behavior. Adaptive unstructured grids facilitate the use of high resolution only where needed (i.e., in the vortex of hurricanes) by the evolving numerical solution. The results of this study indicated that solution-adaptive technique is an effective way of simulating TCs and advantage of using adaptive grid technique is centered in the highest resolution.