Wind Statistics from a Forested Landscape

An analysis and interpretation of measurements from a 138-m tall tower located in a forested landscape is presented. Measurement errors and statistical uncertainties are carefully evaluated to ensure high data quality. A 40 ∘ wide wind-direction sector is selected as the most representative for larg...

Full description

Saved in:
Bibliographic Details
Published in:Boundary-layer meteorology 2015-07, Vol.156 (1), p.53-71
Main Authors: Arnqvist, Johan, Segalini, Antonio, Dellwik, Ebba, Bergström, Hans
Format: Article
Language:English
Subjects:
Above canopy turbulence statistics Atmospheric boundary layers
Above-canopy turbulence statistics
Atmospheric boundary layer
Atmospheric Protection/Air Quality Control/Air Pollution
Atmospheric Sciences
Boundary layers
Decay
Decreasing roughness
Earth and Environmental Science
Earth Sciences
Forest Canopy Flows
Forests
Meteorology
Roughness length
Surface-layer scaling
Turbulence
Wind
Wind power
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:An analysis and interpretation of measurements from a 138-m tall tower located in a forested landscape is presented. Measurement errors and statistical uncertainties are carefully evaluated to ensure high data quality. A 40 ∘ wide wind-direction sector is selected as the most representative for large-scale forest conditions, and from that sector first-, second- and third-order statistics, as well as analyses regarding the characteristic length scale, the flux-profile relationship and surface roughness are presented for a wide range of stability conditions. The results are discussed with focus on the validity of different scaling regimes. Significant wind veer, decay of momentum fluxes and reduction in shear length scales with height are observed for all stability classes, indicating the influence of the limited depth of the boundary layer on the measured profiles. Roughness sublayer characteristics are however not detected in the presented analysis. Dimensionless gradients are shown to follow theoretical curves up to 100 m in stable conditions despite surface-layer approximations being invalid. This is attributed to a balance of momentum decay and reduced shear length scale growth with height. The wind profile shows a strong stability dependence of the aerodynamic roughness length, with a 50 % decrease from neutral to stable conditions.
ISSN:0006-8314
1573-1472
1573-1472
DOI:10.1007/s10546-015-0016-x