Radiative Transfer in Absorbing Aerosols and Snow Grains: Theory and Experiment

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

This project is an evolution of the Principal Investigator's longstanding research on radiative transfer properties of ice, and turns attention to the absorption and scattering of light as altered by contamination of ice particles and snow grains by black carbon (soot) and dust particles of various sizes, shapes and composition. A combination of laboratory experimentation, numerical simulations and theoretical approaches will be applied to this investigation, which will in-part hinge on a geometric photon tracing method to better determine radiative scattering properties of contaminated ice at both visible and infrared wavelengths. A systematic analysis will be undertaken to improve physical understanding and insight into computationally efficient methodologies deriving snow albedo (i.e. energy reflectance) from a radiative transfer model representing both single and multiple snow layers that include a variety of combinations of snow grain size and shape, black carbon/dust-snow mixtures, and realistic variations of the incident angle of solar radiation. The intellectual merit of this work relates to providing a firm theoretical and model-based foundation for reducing uncertainties in climate system forcing associated with changing atmospheric and snowpack conditions. Broader impacts will derive from improved ability to anticipate rapid changes in snowcover via improved model predictions and associated improvements in water resource management in sensitive areas, including but not limited to glaciated mountains and polar regions, as well as through student education at both graduate and undergraduate levels.