STOCHASTICITY IN GEOPHYSICAL AND HYDROLOGICAL TIME SERIES*: Paper presented at the Nordic Symposium on Stochastic Hydrology (Uppsala, Sweden, September 1971)

Most time processes within the atmosphere and oceans, and along the water cycle are periodic-stochastic processes, with the physical basis of the periodicity derived from astronomic cycles and the stochasticity produced by various sources of randomness within the environments of the earth. The atmosphere is the major source of stochasticity in all those geophysical time processes which are connected to the incoming solar radiation, though the oceans, the earth's surface, and the earth's crust also produce the stochasticity. The main influence of the oceans and the continental surfaces as well as the underground water is, however, to attenuate the high stochasticity produced by the atmosphere. It is concluded that without stochastic meteorology a good understanding of many geophysical stochastic processes will be difficult.