Drizzle and Turbulence Variability in Stratocumulus-topped Boundary Layers

Abstract:

Marine stratocumulus clouds frequently produce light precipitation in the form of drizzle. The drizzle rate at the cloud base (R_CB) dictates the impact of drizzle on the boundary layer turbulence and cloud organization. Here, synergistic observations from the US Department of Energy Atmospheric Radiation Measurement (ARM) program Eastern North Atlantic (ENA) site located on Graciosa Island in the Azores are used to investigate the relationship between R_CB, and boundary layer turbulence and dynamics. The ARM ENA site is a heavily instrumented ground-based facility that offers new measurement capabilities in stratocumulus-topped boundary layers (STBL). The R_CB is retrieved using a radar-lidar algorithm. The STBL turbulent structure is characterized using the Doppler lidar and radar observations. The profiling radar/lidar/radiometer observations are used to describe the cloud fraction and morphology. Finally, surface-based aerosol number concentration measurements are used to investigate the connection between the boundary layer turbulence, cloud morphology and aerosol loading. Preliminary correlative relationships between the aforementioned variables will be shown.