Numerical Simulation of Cloud Seeding Experiments in Maharashtra State, India
Two numerical cloud seeding simulation experiments of 5-, 8- and 10-years duration, with a double area cross-over design and area randomization, were performed using historic rainfall data for the Deccan plateau region in Maharashtra state.
The first numerical experiment (EXP-TR) used the simulation technique of Twomey and Roberstson (1973), second (EXP-MMM) used different simulation technique proposed in the present study. The results of the two numerical experiments have agreed closely. The EXP-MMM technique not only reduces computational time by an order of magnitude but also defines the exact lower limit for the double ration value which can be detected at 5 per cent level of significance.
The results of the numerical experiments suggest that 15 and 20 percent increases in rainfall due to seeding in Maharashtra could be detected, with 80 percent or more probability, in 5 years. In a 10-year experiment the probabilities of detecting 5 and 10 percent increases in rainfall due to seeding are 27 and 65 percent, respectively.