Naslov
A theory for the estimation of surface fluxes in simple katabatic flows

Autori
Grisogono, Branko ; Oerlemans, Johannes

Izvornik
Quarterly Journal of the Royal Meteorological Society (0035-9009) 127 (2001), 578; 2725-2739 Part B

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
low-level jet; WKB method; midlatitude glacier; boundary-layers; turbulence; roughness; summer; profiles; momentum; heat

Sažetak
The classical Prandtl model describes the basic dynamics of katabatic flows, but it fails in determining the gradients near the surface because the eddy diffusivity, K, is independent of height, z. An improvement is proposed to the Prandtl model by using the WKB method to solve the dynamic equation for any prescribed, reasonably smooth, K(z) profile. The surface fluxes are obtained by extrapolation from the katabatic jet down to the surface, thus the fluxes depend primarily on the jet which is well captured by the WKB method. The profiles of wind. temperature, momentum and heat fluxes, as well as the surface fluxes calculated using the model, are tested against observations from a meteorological field campaign on the Pasterze glacier, Austria, in 1994, and their numerical simulations. Generally there is a good agreement between observations and theory.

Izvorni jezik
Engleski

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