Boundary layer clouds include stratus, stratocumulus, and fair-weather cumulus. Such clouds are ubiquitous over many parts of the globe and strongly influence the Earth’s radiative energy balance. Our understanding of these clouds is insufficient to solve pressing scientific problems. The need for a better understanding of boundary layer clouds can only be achieved by acquiring high-quality in situ data that can be applied to process studies, fine-scale model evaluation, and the refinement of retrieval algorithms.
A first-of-a-kind, extended-term cloud aircraft campaign was conducted to obtain an in situ statistical characterization of continental boundary-layer clouds. Coordinated by the Atmospheric Radiation Measurement (ARM) Aerial Facility (AAF), the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign operated over the ARM Southern Great Plains site for 5 months from January to June 2009.
A comprehensive payload aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft measured cloud microphysics, solar and thermal radiation, physical aerosol properties, and atmospheric state parameters. Among many other studies using these data, the RACORO aircraft data are being used to construct case studies to assess and improve models of continental boundary-layer clouds as part of the FAst-physics System TEstbed and Research (FASTER) project.