Evaluation of the Cloud Particle Imager (CPI) and Microphysical Investigations of Wave, Cirrus and Anvil Clouds

Stratton Park Engineering Co., Inc., Boulder CO

Investigators

Abstract

This project is a continuation of the evaluation and application of the CPI (Cloud Particle Imager), an airborne instrument that produces high-resolution images of cloud particles down to a size of several micrometers, far exceeding the capabilities of other instruments. The CPI is being improved by addition of a dual 2D-stereo imaging probe funded by the Office of Naval Research. It will be flown on a Learjet in wave and anvil clouds to investigate the sizes, crystal habit, growth, and concentration of ice crystals in different environmental conditions. Separate ground-based experiments will be carried out at the Storm Peak Observatory in two winter seasons to compare CPI images of ice crystals with images of the drops formed as they melt. This will provide a better definition of the relation between the size and shape of ice crystals and their mass, and will enable the CPI in airborne experiments to be used for estimating the mass of ice per unit volume of cirrus clouds. The combination of laboratory experiments, theoretical analysis, and ground-based and airborne experiments will greatly increase the data available on ice crystals in natural clouds at cold temperatures. The information is important for both cloud physics and for predicting the effects of cirrus clouds on the transfer of solar and infrared radiation.