P3.11
The linear acoustic and gravity wave response to localized heating in a compressible atmosphere
Jeffrey M. Chagnon, Penn State Univ., University Park, PA; and P. R. Bannon
The role of acoustic and gravity waves in the adjustment of a compressible atmosphere to an instantaneous, localized heat source is examined. An analytic solution to the 3-D, time-dependent, linear hydrostatic and geostrophic adjustment problem is obtained using a separation of variables technique. The horizontal structure is solved via the Fourier transform. The vertical structure is described by a Sturm-Liouville equation, whose solution is a linear combination of vertically orthogonal eigenfunctions. Each of these eigenfunctions has a unique time-dependence implied by the initial conditions and the dispersion relation. In this manner, we represent the solution as an explicit sum of acoustic and gravity waves, a Lamb mode, and a potential vorticity conserving steady-state. The time-dependent energetics have a similar orthogonal representation. The wave energetics are thus partitioned between acoustic and gravity waves, illuminating the contrasting roles of these waves in the hydrostatic and geostrophic adjustment process.
Poster Session 3, Atmospheric Dynamics II—Eyeopener (Continental Breakfast)
Tuesday, 5 June 2001, 8:30 AM-10:00 AM
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