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Title: The macroscopic behavior of cumulus ensembles simulated by a cumulus ensemble model

Journal Article · · Journal of the Atmospheric Sciences; (United States)
OSTI ID:6712192
; ;  [1]
  1. Univ. of California, Los Angeles (United States)

The two-dimensional UCLA cumulus ensemble model (CEM), which covers a large horizontal area with a sufficiently small horizontal grid size, is used in this study. A number of simulation experiments are performed with the CEM to study the macroscopic behavior of cumulus convection under a variety of different large-scale and underlying surface conditions. Specifically, the modulation of cumulus activity by the imposed large-scale processes and the eddy kinetic energy (EKE) budget are investigated in detail. In all simulations, cumulus convection is rather strongly modulated by large-scale advective processes in spite of the existence of some nonmodulated high-frequency fluctuations. The modulation exhibits some phase delays, however, when the basic wind shear is strong. This is presumably associated with the existence of mesoscale convective organization. The EKE budget analysis shows that the net eddy buoyancy generation rate is nearly zero for a wide range of cumulus ensembles. 34 refs., 17 figs., 2 tabs.

DOE Contract Number:
FG02-92ER61363
OSTI ID:
6712192
Journal Information:
Journal of the Atmospheric Sciences; (United States), Vol. 49:24; ISSN 0022-4928
Country of Publication:
United States
Language:
English