Convective activity in the tropical western Pacific strongly influences frequency of occurrence and microphysical properties of cirrus clouds. Cirrus clouds typical of convectively active regions tend to have larger depths and more structure than those observed in suppressed regions, where cirrus is often thin and laminar. In this study, we examine cirrus occurrence and radiative properties observed over two sites in the tropical western Pacific as part of the U. S. Department of Energy, Atmospheric Radiation Measurement (ARM) program. Combined ground-based infrared radiometer and lidar measurements demonstrate the differences in cirrus properties and cloud occurrence at each location. The dynamical mechanisms typically responsible for cirrus formation at each site greatly impacts local cirrus properties and radiative heating rates, which influences both the radiation budget and dynamical response of the upper troposphere to the presence of cirrus clouds.