title: Wind noise under a pine tree canopy.
abstract: It is well known that infrasonic wind noise levels are lower for arrays placed in forests and under vegetation than for those in open areas. In this research, the wind noise levels, turbulence spectra, and wind velocity profiles are measured in a pine forest. A prediction of the wind noise spectra from the measured meteorological parameters is developed based on recent research on wind noise above a flat plane. The resulting wind noise spectrum is the sum of the low frequency wind noise generated by the turbulence-shear interaction near and above the tops of the trees and higher frequency wind noise generated by the turbulence-turbulence interaction near the ground within the tree layer. The convection velocity of the low frequency wind noise corresponds to the wind speed above the trees while the measurements showed that the wind noise generated by the turbulence-turbulence interaction is near stationary and is generated by the slow moving turbulence adjacent to the ground. Comparison of the predicted wind noise spectrum with the measured wind noise spectrum shows good agreement for four measurement sets. The prediction can be applied to meteorological estimates to predict the wind noise under other pine forests.
authors.affiliation: National Center for Physical Acoustics, Department of Physics and Astronomy, The University of Mississippi, Box 1848, University, Mississippi 38677.
authors.forename: Richard
authors.initials: R
authors.lastname: Raspet
authors.affiliation: National Center for Physical Acoustics, Box 1848, University, Mississippi 38677.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Webster
mesh_terms: D000162:Acoustics / Q000295:instrumentation; D003198:Computer Simulation; D008962:Models, Theoretical; D009038:Motion; D009622:Noise; D028223:Pinus; D011312:Pressure; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013018:Sound Spectrography; D013997:Time Factors; D014160:Transducers, Pressure; D014919:Wind