Accessibility navigation


Estimation of surface-layer scaling parameters in the unstable boundary layer: implications for orographic flow speed-up

Argain, J. L., Teixeira, M. and Miranda, P. M. A. (2017) Estimation of surface-layer scaling parameters in the unstable boundary layer: implications for orographic flow speed-up. Boundary-Layer Meteorology, 165 (1). pp. 145-160. ISSN 0006-8314

[img]
Preview
Text - Accepted Version
· Please see our End User Agreement before downloading.

1MB

It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1007/s10546-017-0260-3

Abstract/Summary

A method is proposed for estimating the surface-layer depth (zs) and the friction velocity (u∗) as a function of stability (here quantified by the Obukhov length, L) over the complete range of unstable flow regimes. This method extends that developed previously for stable conditions by Argaín et al. (Boundary-Layer Meteorol 130:15–28, 2009), but uses a qualitatively different approach. The method is specifically used to calculate the fractional speed-up (ΔS) in flow over a ridge, although it is suitable for more general boundary-layer applications. The behaviour of zs(L) and u∗(L) as a function of L is indirectly assessed via calculation of ΔS(L) using the linear model of Hunt et al. (Q J R Meteorol Soc 29:16–26, 1988) and its comparison with the field measurements reported in Coppin et al. (Boundary-Layer Meteorol 69:173–199, 1994) and with numerical simulations carried out using a non-linear numerical model, FLEX. The behaviour of ΔS estimated from the linear model is clearly improved when u∗ is calculated using the method proposed here, confirming the importance of accounting for the dependences of zs(L) and u∗(L) on L to better represent processes in the unstable boundary layer.

Item Type:Article
Refereed:Yes
Divisions:Faculty of Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
ID Code:70672
Uncontrolled Keywords:Convective boundary layer; Flow speed-up; Friction velocity; Surface-layer height; Unstable stratification
Publisher:Springer

Downloads

Downloads per month over past year

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation