Mesoscale variability of turbulence-generating mechanisms in southeast-Pacific stratocumulus
Prescott R. Bishop, North Carolina State Univ., Lawrence, KS; and D. B. Mechem, S. E. Yuter, S. P. de Szoeke, and C. Burleyson
Boundary layer cloud systems over the southeast Pacific are frequently characterized by cells of precipitation associated with strong updraft/downdraft couplets that are embedded in broad regions of stratocumulus. Cloud-top radiative cooling is the predominant mechanism for generating turbulent kinetic energy (TKE) in the stratocumulus regions. Positive vertical velocity skewness in the precipitation cells, on the other hand, implies a circulation rooted in the subcloud layer and largely independent of cloud-top cooling mechanisms. A series of numerical simulations serve to isolate the relative importance of cloud top radiative cooling (top–down) and surface-driven (bottom–up) buoyancy mechanisms in establishing the mesoscale structure of cloud and turbulence properties.
Poster Session 1, Poster session I
Monday, 1 August 2011, 2:30 PM-4:00 PM, Marquis Salon 3
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