The temporal and spatial variability of rainfall power

摘要

AbstractIn this paper a statistical model of raindrop size distributions is used to examine the temporal variability of rainfall power and to develop techniques for estimating rainfall power from observations of rainfall rate and radar reflectivity factor. The model of raindrop size distributions is based on the assumptions that: 1) raindrop arrival rate at the ground can be represented by a Poisson process with randomly varying rate of occurrence and 2) diameters of raindrops have a lognormal distribution with parameters that are time‐varying random processes. The lognormal distribution plays a central role in both characterization of the temporal variability of rainfall power and in state estimation of rainfall power from rainfall rate and radar reflectivity observations. Empirical results are presented using drop‐size data from a number of sites in the United States. Spatial variability of rainfall power is examined empirically using the rainfall power‐reflectivity relationships developed from drop‐size data and radar data from the southern plains region of the United