Observation and Analysis of Midwestern Rain Rates

Abstract

A prototype meteorological station has been established in Iowa City for the measurement of surface meteorological parameters with accuracy and resolution sufficient to allow for modern dimensional and scaling analyses. The sensor characteristics are presented and an initial analysis of the rain-rate time series of seven storms with high quality data yielded the following results: (a) scaling exists for the short timescales, which in most cases extended up to a few tens of seconds, and it does not extend to the longer timescales for all the storms, and (b) four of the seven storms exhibit hyperbolic behavior of the exceedance probability distributions, with the value of the associated exponent in most cases being near 2 but higher than the values obtained previously from radar and conventional rain gauge data. Analysis of the time series of concurrent surface meteorological variables for a particular spring storm shows that there is interdependence of the time series with an implied reduction of the dimension of the state space of local surface rainfall.