Distribution Functions of Probabilities of Cyclones and Anticyclones from 1952 to 2000: An Instrument for the Determination of Global Climate Variations

摘要

Global climate changes are not desirable and are even dangerous for two reasons. Slow variations in mean values, such as air temperature at the surface, lead to prolongation of the period without frost, decreasing of the time favorable for winter sports, and other changes. On the other hand, a shift in the mean characteristics leads to variations in the distribution functions for hazardous and even catastrophic events such that they can become more frequent and intense. Moreover, they can appear in atypical regions, where the population is not accustomed to such events. The standard procedure is currently as follows: the percentage of probability of draughts, floods, frosts, hot weather periods, or other extreme phenomena are calculated on the basis of observation data or climate models. Then variations for other climatic periods are analyzed relative to their intensity, duration, recurrence frequency, and so on. Analysis of their distribution functions related to the target parameter is a more detailed and representative method to understand the variations in the statistics mentioned above. We have calculated such distribution functions related to the intensity and area of cyclones and anticyclones based on the data of reanalysis weather charts for the second half of the 20th century. They have an exponential character. The variations in such distribution functions are most informative for determining climate changes.