USE OF RAMAN SPECTROSCOPY TO DETERMINE THE LIQUID WATER CONTENT OF SNOW

Abstract

This article shows Raman spectra of water in the liquid (a) and solid (b) states. There are considerable differences between these spectra. We have made a detailed study of the alteration of the spectra when water crystallizes, using various types of excitation and measurement of the spectra. With a 180° recording geometry, the Raman spectrum of a two-phase mixture (solid and liquid) represents a superposition of the spectra of water and ice. A direct consequence of this is the conclusion that it may be possible to determine the partial volumes of the two phases in the mixture. We used a device in which the Raman spectrometer recorded radiation backscattered 180° relative to the exciting radiation at the Stokes frequencies, and a 300 mW LG-106M-1 argon laser operating at 488 nm. We obtained high-quality Raman spectra from the surface of freshly fallen snow.