Raman spectroscopy probes the chemical and physical states of matter through inelastic scattering from the vibrational rotational and low frequency modes of molecular systems. In the atmosphere, one of the most abundant Raman scatterers is water, in its ice, liquid and vapour phases, and in their admixture. This EAGER award seeks to improve the feasibility of Raman spectroscopy combined with polarimetric Lidar (light detection and ranging) to remotely profile the fraction of water phases in tropospheric aerosols and cloud layers.
This proposal meets one or more of the EAGER criteria because the work is exploratory in nature and the particular approach, using a near IR Fourier Transform Spectrometer (FTS) theoretically capable of the requisite high spectral resolution, is largely untested in this configuration. The ability of the FTS to perform satisfactorily under high background light conditions (e.g. daylight or twilight) is likely to be a main element of proposal risk.
