Collaborative Research: The Meteorological Variability of the Two Dimensional/Temporal Structures of Drop Size Distributions and Rain

College Of Charleston, Charleston SC

Investigators

Abstract

This award provides funding for researchers to study the topic of raindrop clustering. As can be seen in nature, rain does not fall with equal spacing between the individual drops. Rather, the raindrops tend to cluster or bunch. This can make the interpretation of tools used to measure rainfall, such as simple rain gauges or advanced weather radar, more complicated. In this study, researchers from two institutions will expand a measuring site that includes a significant number of disdrometers, which are instruments that can provide images and information about individual raindrops as they fall. The additional data will help the researchers answer a variety of questions which are ultimately relevant to the interpretation of data from radar and the effect of rain on soil erosion. Undergraduate students would be directly involved in the collection and analysis of the data, providing opportunities for the next generation of scientists. The research team will continue and expand upon their work making measurements of small scale variability in rainfall. In their prior research grant, the researchers set up an array of optical disdrometers and a video disdrometer within a small 100m x 100m area. This award will add a second video disdrometer and a newer type of optical disdrometer in order to collect data that would answer questions raised by the investigation of the original data. Specifically, the research plan is to: (1) expand the library of data to obtain better and more complete sets of observations in a wider variety of meteorological conditions, (2) achieve higher temporal resolution of some instruments to reduce advection smoothing, particularly for more detailed studies of the spatial pair correlation function, (3) characterize further the spatial correlation function for many more rain events beyond the current 100m, (4) focus on centimeter scale studies using 2DVD data yet to be explored with particular regard to scales relevant to radar Bragg scatter, (5) expand the study of the effect of domain size on drop size distribution and their integrated parameters to include more data sets under different meteorological conditions, (6) focus on calculating 2D spatial correlation in different meteorological settings and different temporal resolutions with the aim of developing useful parametric expressions for applications, and (7) combine 2DVD observations from two instruments for unique simultaneity studies similar to historic and prize winning photon work.