Extended Abstract (124K)P3.24
Diagnoses and numerical simulations of turbulence in the vicinity of coastal topography
Douglas K. Miller, NPS, Monterey, CA; and D. L. Walters
Special observations were made of atmospheric turbulence over the period from 18 through 26 October 2001 at Vandenberg Air Force Base located in the vicinity of the coastal mountains of Southern California. Standard rawinsondes and thermosondes were launched in addition to continuous measurements being made by a high resolution profiler reaching altitudes of up to 17 km. During the early portion of the period (18-22 October), a strong upper level jet developed and propagated over the Vandenberg site. The evolution of its associated turbulence and gravity wave development as it interacted with the coastal mountains will be diagnosed from the special observations which will be compared to numerical model simulations.
A method for estimating mixing length in the prediction of turbulent kinetic energy by the Navy's Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) has been documented (Walters and Miller 1999, Walters and Miller 2001). The ability of the method to capture essential turbulence and gravity wave structures associated with the interaction of the jet with coastal topography will be examined in detail over the nine day period. Turbulence in COAMPS is generated using a modified form of the Mellor and Yamada (1982) 2.5 closure scheme for parameterizing mixing length. Model turbulence results will be compared to a simplified diagnostic approach using forecasts generated by the real-time Naval Postgraduate School MM5 model simulations over the nine day period.
Poster Session 3, Topographic Flows (with Coffee Break)
Thursday, 20 June 2002, 2:45 PM-4:30 PM
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