Comparison of Cirrus Cloud Radiative Properties and Dynamical Processes at Two Atmospheric Radiation Measurement Sites in the Tropical Western Pacific

Upper tropospheric humidity plays an important role in the formation and maintenance of tropical cirrus clouds. Deep convection is crucial for the transport of water vapor from the boundary layer to the upper troposphere and is responsible for the formation of anvil cirrus that can spread horizontally over considerable distances and persist for several hours. In addition, recent studies have linked large-scale stratospheric dynamics to the presence of tropical cirrus clouds that are not necessarily linked directly with deep convection. In this study, we use ground-based remote sensing measurements, obtained from the U. S. Department of Energy, Atmospheric Radiation Measurement (ARM) sites located on Manus and Nauru Islands, to retrieve cirrus properties, such as cloud height, thickness, and visible optical depth. We then examine differences in top of the atmosphere (TOA) and surface radiation budgets observed at each site, which helps determine the amount of convective activity that influences each location. Comparisons of cloud properties also reveal the influence of deep convection and large-scale dynamics on cirrus radiative properties.