TY - JOUR

T1 - Vertical cross-spectral phases in neutral atmospheric flow

A1 - Chougule,Abhijit S.

A1 - Mann,Jakob

A1 - Kelly,Mark C.

A1 - Sun,J.

A1 - Lenschow,D. H.

A1 - Patton,E. G.

AU - Chougule,Abhijit S.

AU - Mann,Jakob

AU - Kelly,Mark C.

AU - Sun,J.

AU - Lenschow,D. H.

AU - Patton,E. G.

PB - Taylor & Francis Ltd.

PY - 2012

Y1 - 2012

N2 - The cross-spectral phases between velocity components at two heights are analyzed from observations at the Hovsore test site and from the field experiments under the Cooperative Atmosphere-Surface Exchange Study in 1999. These phases represent the degree to which turbulence sensed at one height leads (or lags) in time the turbulence sensed at the other height. The phase angle of the cross-wind component is observed to be significantly greater than the phase for the along-wind component, which in turn is greater than the phase for the vertical component. The cross-wind and along-wind phases increase with stream-wise wavenumber and vertical separation distance, but there is no significant change in the phase angle of vertical velocity, which remains close to zero. The phases are also calculated using a rapid distortion theory model and large-eddy simulation. The results from the models show similar order in phasing, but the slopes of the phase curves are slightly different from the observations, especially for low wavenumbers.

AB - The cross-spectral phases between velocity components at two heights are analyzed from observations at the Hovsore test site and from the field experiments under the Cooperative Atmosphere-Surface Exchange Study in 1999. These phases represent the degree to which turbulence sensed at one height leads (or lags) in time the turbulence sensed at the other height. The phase angle of the cross-wind component is observed to be significantly greater than the phase for the along-wind component, which in turn is greater than the phase for the vertical component. The cross-wind and along-wind phases increase with stream-wise wavenumber and vertical separation distance, but there is no significant change in the phase angle of vertical velocity, which remains close to zero. The phases are also calculated using a rapid distortion theory model and large-eddy simulation. The results from the models show similar order in phasing, but the slopes of the phase curves are slightly different from the observations, especially for low wavenumbers.

KW - Cross-spectra

KW - Phases

KW - Atmospheric turbulence

KW - Wavenumber

KW - Vertical distance

U2 - 10.1080/14685248.2012.711524

DO - 10.1080/14685248.2012.711524

JO - Journal of Turbulence

JF - Journal of Turbulence

SN - 1468-5248

IS - 36

VL - 13

SP - 1

EP - 13

ER -