P2.6
Analysis of convective downdrafts and microbursts using a simple, one-dimensional model
Daniel T. Lindsey, Colorado State University, Fort Collins, CO; and D. A. Randall
This paper describes and utilizes a simple convective downdraft model to analyze the structure and intensity of thunderstorm downdrafts. The model is one-dimensional and steady-state. Rain falls from a tilted updraft into sub-saturated air, where it evaporates, cools the column of air, and produces a negatively buoyant parcel which becomes a downdraft. The environmental profile and incoming rain flux are varied and the resulting downdrafts are examined.
In addition to the model, radar data is analyzed to observe downdraft structure. Calculated vertical velocities within two convective systems are compared with model results, and observed errors are discussed.
Finally, the model is used to simulate microbursts produced from precipitation falling into a very dry boundary layer, like what may be observed in eastern Colorado during the summer.
Supplementary URL: http://kiwi.atmos.colostate.edu/BUGS/groupPIX/daniel/Pdaniel.html
Poster Session 2, Convectively Driven High Wind Events
Monday, 12 August 2002, 3:00 PM-4:30 PM
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