Measurements of drop size distributions at McGill The measurements and interpretation of raindrop size distributions (DSD) concentrates on the shapes of the DSD functions for equilibrium and non-equilibrium cases, as well as identifying the shapes for different hydrometeors (such as rain, freezing rain, and melting snow). The research is conducted from an observational point of view, taking the advantage of the McGill's remote sensing capabilities, and the following three sensors:


(1) The Joss-Waldvogel Distrometer, JWD: A Swiss instrument that converts raindrops' vertical momentum into drop diameters. It is the classic instrument for the measurement of DSD's.

(2) Two optical distrometers developed at ETH (Zurich) that image rain and snow particles.

(3) Parsivel: This is a laser-based optical disdrometer for the measurement of all kinds of precipitation one meter obove the earth's surface. The primarily determined data are the size and the velocity of each individual precipitation particle, from which the size spectrum, the amount of precipitation, the equivalent radar reflectivity, the visibility and the kinetic precipitation energy as well as the kind of precipitation are derived.

(4) Micro Rain Radar MRR-2: Microwave profile for the measurement of rain rate, liquid water content and drop size distribution from near ground to a few kilometers.

Other instruments Finally, we also operate a weather station downtown, and a GPS receiver at the Radar Observatory part of Suominet used to measure vertically integrated vapor amounts.