This grants supports acquisition of portable spectroradiometer by PIs G. Okin and N. Molotch in the Department of Geography at the University of California Los Angeles. The investigators will conduct field investigations of the spectral properties of alpine snow pack and desert soils and sediments. Field measurement of the spectral properties of snow pack can improve understanding of climatic and hydrological implications of snow cover dynamics through use as ground truth to regional space borne microwave emission estimates of snow reflectance (albedo) and by providing a method to better constrain the vertical distribution of snow grain size from excavated snow pits. Snow grain size distribution is an important determinant of springtime melting dynamics. Spectral evaluation of desert soils allows estimation of wind erodibility and mineral composition and can provide input to models of dust emission and transport. Understanding the sources, composition and dynamics of mineral aerosols have important implications for human health, agricultural productivity and climate, the latter through its effect on Earth?s albedo. The instrument will also support student research and research training.