This presentation examines the changing cryosphere and specifically the role of black carbon on the reflectivity of snow. Small amounts of black carbon in snow purportedly contribute to a reduction in snow albedo, contributing to regional climate change and early onset of melting. Our current research focuses on the connection between black carbon and albedo reduction. This presentation will describe our laboratory experiments wherein we make and characterize pure and contaminated snow and assess the black carbon snow albedo reduction as a function of black carbon mixing ratio and snow grain size. Experimental results are compared to verify or refute the snow radiation models that feed climate models. For more information about this seminar, please contact: JoAnne Lambert 510.486.4835, or send e-mail to JMLambert[at]lbl.gov