We have made airborne measurements of spectral optical depths, radiative fluxes, and scattered radiation fields during the NASA Caribbean mission (July7--14, 1991) to characterize the Pinatubo volcanic cloud. In this paper we report the latitudinal and spectral dependence of the volcanic cloud's optical depth. From these measurements we determine moments of the particle size distribution. The change in planetary albedo induced by the volcanic cloud is calculated for the range of measured optical depths with the objective of assessing the impact on the solar radiation budget. Mid-visible optical depths higher than 0.4 were observed, placing the Pinatubo stratospheric cloud among the thickest ever measured. The latitudinal distribution of extinction shows that by July 7, 1991 the volcanic cloud had extended to 30 ¿N. The effective particle radius was determined to be between 0.18 &mgr;m and 0.35 &mgr;m with a corresponding columnar mass loading between 35 and 80 mg.m-2. ¿American Geophysical Union 1992