Parametrizing horizontally-averaged wind and temperature profiles in the urban roughness sublayer

Theeuwes, N. E. ORCID: https://orcid.org/0000-0002-9277-8551, Ronda, R. J., Harman, I. N., Christen, A. and Grimmond, C. S. B. ORCID: https://orcid.org/0000-0002-3166-9415 (2019) Parametrizing horizontally-averaged wind and temperature profiles in the urban roughness sublayer. Boundary-Layer Meteorology, 173 (3). pp. 321-348. ISSN 0006-8314 doi: 10.1007/s10546-019-00472-1

Abstract/Summary

Tower-based measurements from within and above the urban canopy in two cities are used to evaluate several existing approaches that parametrize the vertical profiles of wind speed and temperature within the urban roughness sublayer (RSL). It is shown that current use of Monin–Obukhov similarity theory (MOST) in numerical weather prediction models can be improved upon by using RSL corrections when modelling the vertical profiles of wind speed and friction velocity in the urban RSL using MOST. Using anisotropic building morphological information improves the agreement between observed and parametrized profiles of wind speed and momentum fluxes for selected methods. The largest improvement is found when using dynamically-varying aerodynamic roughness length and displacement height. Adding a RSL correction to MOST, however, does not improve the parametrization of the vertical profiles of temperature and heat fluxes. This is expected since sources and sinks of heat are assumed uniformly distributed through a simple flux boundary condition in all RSL formulations, yet are highly patchy and anisotropic in a real urban context. Our results can be used to inform the choice of surface-layer representations for air quality, dispersion, and numerical weather prediction applications in the urban environment.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/85669
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Springer
Download/View statistics	View download statistics for this item