During the 2002 CRYSTAL-FACE experiment, depolarization lidar instruments were operated both at the ground and from an airborne platform. Linear depolarization ratios from thunderstorm anvil measurements made by these two YAG-based (532 nm) systems, the University of Utah Polarization Diversity Lidar (PDL) and the Cloud Physics Lidar (CPL) aboard the NASA ER-2 aircraft, are reported. We correlate the occurrence of observed values with respect to ambient thermal properties so as to characterize the scattering characteristics of sub-tropical convective cirrus. We compare our results to those from midlatitudes to infer possible cloud microphysical differences.