Climatology of cloud properties and radiative heating profiles at tropical ACRF sites

Currently, the average net radiative effect of tropical clouds at the top of the atmosphere (TOA) is small, due to compensating longwave and shortwave effects. As Earth's climate warms, characteristics of tropical convection and associated radiatively important clouds may change, leading to changes in the TOA radiative effects. The ARM Climate Research Facility (ACRF) operates three measurement sites in the tropical western Pacific (TWP) region at Manus, Papua New Guinea (since 1996), the island nation of Nauru (since 1998), and Darwin, Australia (since 2002). These sites are the only long-term ground measurement sites in the tropics that contain advanced remote sensing instrumentation, such as cloud radar and lidar, which allow detailed characterization of cloud microphysical and macrophysical properties, the diurnal cycle of cloud properties, and cloud vertical structure. We present climatologies of derived cloud properties and radiative heating profiles at the three sites using a newly developed retrieval algorithm, with a focus on cirrus and mid-level clouds.