A Re-examination of the “Leipzig Wind Profile” Considering some Relations between Wind and Turbulence in the Frictional Layer

The history of the development of Rossby-Number Similarity Theory for the neutral Planetary Boundary Layer (PBL) is reviewed. It is shown that the logarithmic profile derived by asymptotic matching is only valid in the matched layer and not in the surface layer proper. Derivation of the traditional PBL Resistance Laws from the theory is outlined. A best-fit polynomial through observations of geostrophic drag coefficients suggests that the traditional form of the Resistance Laws is inadequate. A new formulation is derived from a generalization of the theory that allows the logarithmic form of the wind profile in the matched layer to differ from that in the surface layer. This new formulation is evaluated against observations made during the 1967 Wangara Experiment. Finally, it is demonstrated how wind speed and wind shear profiles that are consistent with the new Resistance Laws may be obtained.

Section: Refinement Of the New Pbl Resistance Lawmentioning

confidence: 99%

Proposal for new PBL resistance laws for neutrally-stratified flow

Walmsley

1992

“…The material collected and evaluated for these lectures was later published under the course title. Chapter 7 of this monograph (Lettau, 1938) was headed 'Atmosphaerische Grenzschichten' and the term translated 'planetary boundary layer' appeared for the first time in the literature.…”

Section: Boundary-layer Meteorologymentioning

confidence: 99%

The O'Neill experiment of 1953

Lettau

1990

Self Cite

“…For his calculations by means of the method of geostrophic departure, Mildner obtained the geostrophic wind from synoptic charts while Lettau (1950Lettau ( , 1957, Lettau and Hoeber (1964) and Lettau and Zhang (1982) estimated it indirectly from wind profiles by special formulas without knowledge of the horizontal pressure gadient. Lettau's procedure was adopted by Johnson (1962Johnson ( ,1965, Leykauf (1974) and Joffre (1982).…”

Section: Introductionmentioning

confidence: 99%

A case study of nocturnal wind and temperature profiles over the inhomogeneous terrain of Northern Germany with some considerations of turbulent fluxes

Wittich

Roth

1984

Soundings in the stably-stratified boundary layer were executed over the rough terrain of Northern Germany during a night with a low-level jet (LU) development. Vertical wind and temperature profiles were obtained at 5 m height intervals using a tethersonde transported up and down along a 300 m high radio tower by an elevator. From these profiles, turbulent fluxes of heat and momentum, coefficients of eddy diffusivity and boundary-layer parameters were estimated. The nocturnal mean state analysis agrees well with the second-order model results of Brost and Wyngaard (1978) and our own first-order numerical testing while the time histories of different profile groups are in accordance with the observations of Izumi and Barad (1963).