Variation of boundary-layer wind spectra with height

Xiaoli Guo Larsén*, Erik L. Petersen, Søren Ejling Larsen

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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Abstract

This study revisits the height dependence of the wind speed power spectrum from the synoptic scale to the spectral gap. Measurements from cup anemometers and sonics at heights of 15 m to 244 m are used. The measurements are from one land site, one coastal land‐based site and three offshore sites in the mid‐latitudes. There are two new findings. The first finding addresses the diurnal peak in the power spectrum. Our analysis suggests that there are two sources that contribute to the diurnal peak. One is related to surface‐driven processes and another one is related to pressure perturbation from the atmospheric tide. The second finding regards the height dependence of the general spectrum. We describe the dependence through a so‐called effective roughness, which is calculated from wind spectra and represents the energy removal at different frequencies, and thus surface conditions in the footprint areas. The generalizable spectral properties of winds presented herein may prove useful for validating numerical models.
Original languageEnglish
JournalQuarterly Journal of the Royal Meteorological Society
Volume144
Issue number716
Pages (from-to)2054-2066
Number of pages13
ISSN0035-9009
DOIs
Publication statusPublished - 2018

Keywords

  • Diurnal cycle
  • Diurnal spectral peak
  • Effective roughness
  • Spectral gap

Cite this

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title = "Variation of boundary-layer wind spectra with height",
abstract = "This study revisits the height dependence of the wind speed power spectrum from the synoptic scale to the spectral gap. Measurements from cup anemometers and sonics at heights of 15 m to 244 m are used. The measurements are from one land site, one coastal land‐based site and three offshore sites in the mid‐latitudes. There are two new findings. The first finding addresses the diurnal peak in the power spectrum. Our analysis suggests that there are two sources that contribute to the diurnal peak. One is related to surface‐driven processes and another one is related to pressure perturbation from the atmospheric tide. The second finding regards the height dependence of the general spectrum. We describe the dependence through a so‐called effective roughness, which is calculated from wind spectra and represents the energy removal at different frequencies, and thus surface conditions in the footprint areas. The generalizable spectral properties of winds presented herein may prove useful for validating numerical models.",
keywords = "Diurnal cycle, Diurnal spectral peak, Effective roughness, Spectral gap",
author = "Lars{\'e}n, {Xiaoli Guo} and Petersen, {Erik L.} and Larsen, {S{\o}ren Ejling}",
year = "2018",
doi = "10.1002/qj.3301",
language = "English",
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pages = "2054--2066",
journal = "Quarterly Journal of the Royal Meteorological Society",
issn = "0035-9009",
publisher = "RMetS, Royal Meteorological Society",
number = "716",

}

Variation of boundary-layer wind spectra with height. / Larsén, Xiaoli Guo; Petersen, Erik L.; Larsen, Søren Ejling.

In: Quarterly Journal of the Royal Meteorological Society, Vol. 144, No. 716, 2018, p. 2054-2066.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Variation of boundary-layer wind spectra with height

AU - Larsén, Xiaoli Guo

AU - Petersen, Erik L.

AU - Larsen, Søren Ejling

PY - 2018

Y1 - 2018

N2 - This study revisits the height dependence of the wind speed power spectrum from the synoptic scale to the spectral gap. Measurements from cup anemometers and sonics at heights of 15 m to 244 m are used. The measurements are from one land site, one coastal land‐based site and three offshore sites in the mid‐latitudes. There are two new findings. The first finding addresses the diurnal peak in the power spectrum. Our analysis suggests that there are two sources that contribute to the diurnal peak. One is related to surface‐driven processes and another one is related to pressure perturbation from the atmospheric tide. The second finding regards the height dependence of the general spectrum. We describe the dependence through a so‐called effective roughness, which is calculated from wind spectra and represents the energy removal at different frequencies, and thus surface conditions in the footprint areas. The generalizable spectral properties of winds presented herein may prove useful for validating numerical models.

AB - This study revisits the height dependence of the wind speed power spectrum from the synoptic scale to the spectral gap. Measurements from cup anemometers and sonics at heights of 15 m to 244 m are used. The measurements are from one land site, one coastal land‐based site and three offshore sites in the mid‐latitudes. There are two new findings. The first finding addresses the diurnal peak in the power spectrum. Our analysis suggests that there are two sources that contribute to the diurnal peak. One is related to surface‐driven processes and another one is related to pressure perturbation from the atmospheric tide. The second finding regards the height dependence of the general spectrum. We describe the dependence through a so‐called effective roughness, which is calculated from wind spectra and represents the energy removal at different frequencies, and thus surface conditions in the footprint areas. The generalizable spectral properties of winds presented herein may prove useful for validating numerical models.

KW - Diurnal cycle

KW - Diurnal spectral peak

KW - Effective roughness

KW - Spectral gap

U2 - 10.1002/qj.3301

DO - 10.1002/qj.3301

M3 - Journal article

VL - 144

SP - 2054

EP - 2066

JO - Quarterly Journal of the Royal Meteorological Society

JF - Quarterly Journal of the Royal Meteorological Society

SN - 0035-9009

IS - 716

ER -