On Integral Measures Of The Neutral Barotropic Planetary Boundary Layer |
| |
Authors: | S. S. Zilitinkevich I. N. Esau |
| |
Affiliation: | (1) Department of Earth Sciences, Meteorology, Uppsala University, Villavägen 16, 75236 Uppsala, Sweden |
| |
Abstract: | Two types of neutral planetary boundary layer (PBL) are distinguished:truly neutral – developed against a neutrally stratified free flow, and conventionally neutral – developed against a background stable stratification. Atmospheric PBLs treated asneutral are almost always conventionally neutral. Theoretical reasoning and results from large-eddy simulation (LES) show that A and B coefficients of the Rossby-number similarity theory are not constants. The same is true for thecoefficient Ch in the Rossby–Montgomery formula for the neutral boundary-layer depth h = Chu*/|f|, where u* is the friction velocity. Contrary to classical ideas, A, B and Ch depend on the ratio N N/|f| of the free-flow Brunt–V*auml;isäl ä frequency N to the absolute value of the Coriolis parameter |f|. This new development can explain why atmospheric and LES estimates of A, B and Ch appear inconsistent. It results from neglecting the fact that atmospheric data for N 102 were compared with LES data for N = 0, violating an obvious requirement of similarity with respect to N. |
| |
Keywords: | Boundary-layer depth Free-flow stability Neutral boundary layer Resistance law |
本文献已被 SpringerLink 等数据库收录! |
|