by Idung Risdiyanto
Many formulations of the problems related to weather predictions have been studied heretofore in dynamic meteorology. Efforts in the hydrodynamic theory of weather prediction have resulted the series of quite complete and physically meaningful formulations of these problems, and at the present accept as the basis for the development of numerical methods. The formulations and methods of weather model problem will be continually improved by the accumulations of new information and technology about mechanism underlying atmospheric processes and computer sciences.
Based on atmospheric processes, numerical weather model has two basic directions being pursued in the theory of short-range weather predictions. The first attempted to improve the barotropic model by using balance equations; the other tried to create baroclinic model using the quasigeostropic approximations (Marchuk,1974). By evaluating the result of studies in the field of short-range weather prediction, it seems proper to conclude that the barotropic models lack a proper physical basis in that they only consider the redistribution of kinetic energy by wave dispersion processes. Baroclinic quasigeostropic models was admitted more complicated in transitions from internal energy to kinetic energy and vice versa. Barotropic predictions model only occasionally predictable, whereas the baroclinic quasigeostropic model could be describe up to 60-70% of all cases of weather phenomena. Short-range weather prediction has temporal and spatial resolution that could not describe for large area or weather conditions in the future. So, extended-range prediction is the most urgent scientific problems of weather prediction, since prognostic schemes for 3-5 days ahead must contain features from both short and long-range weather prediction.
Numerical weather model was developed based on quantitative theory of weather system; there arise various problems of formulation, both of the equations themselves and of the mathematical methods for their solution. The first problem is associated with the formulations of the basic equations for the dynamics and thermodynamics of atmosphere processes, which involve a variety of transitions between different forms of energy. This is primarily a physical problem. And the second problems are computational mathematic application and computer technology (full paper download).