As the finite difference method was used to solve the partial differential equations in KAMM, the atmosphere over each domain was divided into discrete 3-dimensional grids with a selected horizontal spatial resolution. The height of each grid was automatically adjusted by KAMM, depending on the terrain elevation. The horizontal resolution of KAMM can be chosen. The higher resolution is used, the more computing time is required. In this work, to compromise between the resolution of the results and the computing time, the horizontal spatial resolution was selected to be 3×3 km2. The procedure of wind calculation is as follows.
In the first step, the atmospheric data obtained from the radiosondes at 7:00 am local time were used as an initial condition of the model in each domain. In the next step, the model calculated hourly wind speed and other atmospheric parameters at all grids for 24 hours. After completing the calculation for the first day, the model was input with a new atmospheric data of the second day. Then, the calculation was repeated so as to cover a 15 year period (January 1995–December 2009). In overlapping areas of the two adjacent domains, the values of wind speed and direction calculated from both domains were averaged and weighted with a distance factor so that their resulting values are continuous at the boundary of the domains. This calculation was carried out by using the NEC supercomputer (model SX8) of the Steinbuch Center for Computing, Karlsruhe Institute of Technology in Germany by using a remote log-in from Thailand.