Extended Abstract (464K)P1.2
Second- and third-order vertical velocity budgets in cloudy boundary layers
Jean-Christophe Golaz, NRL, Monterey, CA; and S. Wang
Exact numerical budgets of second- and third-order vertical velocity moments were derived from large eddy simulations using the Naval Research Laboratory's COAMPS-LES model. Results from two different boundary layer cloud regimes are presented. The first one is a stratocumulus case and the second is a trade wind cumulus case.
Budgets of the vertical velocity variance have been studied quite extensively in previous studies, but third-order budgets have comparatively received little attention. Whereas the vertical velocity variance gives a broad measure of the strength of the turbulence, the third-order reveals more details about the organization of the turbulence, in particular the symmetry - or asymmetry - between updrafts and downdrafts.
Analysis of the third-order vertical velocity budget reveals interesting differences between the various cloud regimes simulated. In particular, the buoyancy is shown to play a large role in controlling the vertical velocity skewness.
Poster Session 1, Clouds
Tuesday, 10 August 2004, 5:30 PM-5:30 PM, Casco Bay Exhibit Hall
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