Atmosphere Ocean Science Colloquium

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Big Science with Little Data: A New Wave-Vortex Decomposition Method for One-Dimensional Spectra in the Atmosphere and Ocean

Speaker: Oliver Buhler, Courant

Location: Warren Weaver Hall 1302

Date: Wednesday, December 3, 2014, 3:30 p.m.

Synopsis:

A simple two-step method is presented by which one-dimensional spectra of horizontal velocity and buoyancy measured along a ship or flight track can be decomposed into a wave component consisting of inertia-gravity waves and a vortex component consisting of a horizontal flow in geostrophic balance. In the first step an exact Helmholtz decomposition of the horizontal velocity spectra into rotational and divergent components is performed and in the second step an energy equipartition property of hydrostatic inertia?gravity waves is exploited that allows diagnosing the wave energy spectrum solely from the observed horizontal velocities. Examples based on two recent oceanic data sets as well as on the classical Gage-Nastrom spectrum for atmospheric motions near the tropopause are given.