Wind turbulence spectra and spatial coherence at Testfeld BHV

Description

This dataset provides 30-min averaged mean flow and turbulence characteristics derived from sonic anemometer, cup anemometer, and short-range WindScanner (SRWS) measurements. The data were collected at the Testfeld BHV site in Bremerhaven, located on the German North Sea coast. The sonic and cup anemometer records cover a 20-month period from January 2021 to August 2022, with observations at three levels between 25 m and 116 m along an IEC-compliant meteorological mast. Additionally, a SRWS system from the DTU Department of Wind and Energy Systems was deployed for six months, consisting of three continuous-wave lidars performing synchronized "bow-tie" scans at heights ranging from 35 m to 230 m. A more detailed description of the dataset and the derived turbulence characteristics is provided in [1].

File overview

Sonic_SinglePointStatistics.mat Mean flow and single-point turbulence characteristics derived from sonic anemometers

Sonic_Coherence.mat Vertical coherence derived from sonic anemometers

Cup_SinglePointStatistics.mat Mean flow and single-point turbulence characteristics derived from cup anemometers

Cup_Coherence.mat Vertical coherence derived from cup anemometers

SRWS_SinglePointStatistics.mat Mean flow and single-point turbulence characteristics derived from SRWS system at the bow-tie centre

SRWS_Coherence_Vertical.mat Mean flow characteristics and vertical coherence derived from SRWS system

SRWS_Coherence_Lateral.mat Mean flow characteristics and lateral coherence derived from SRWS system

Compare_Spectral_Estimates.m MATLAB script to visualize single-point turbulence spectra

Compare_Coherence_Estimates.m MATLAB script to visualize two-point spatial coherence

Compare_Mean_Flow.m MATLAB script to compare mean flow characteristics

Variables

t
Time stamp
UTC

U
Mean wind speed
m/s

WDir
Mean wind direction (0° from N; 90° from E)
deg 

T
Mean absolute temperature
K

var_u, var_v, var_w
Variance of the along-wind, cross-wind, and vertical velocity components
m^2/s^2

cov_uv, cov_uw, cov_vw
Co-variance of the respective velocity components
m^2/s^2

cov_wT
Kinematic heat flux
K m/s

U_star
Friction velocity
m/s

L
Obukhov length
m

S_u, S_v, S_w
Normalized turbulence spectra of the along-wind, cross-wind, and vertical velocity components
-

Co_uw_abs
Normalized co-spectrum of the along-wind and vertical velocity components
-

S_hor
Normalized turbulence spectrum of the horizontal wind speed
-

f_red
Reduced frequency vector for the spectral estimates
-

L_u, L_v, L_w
Integral length scales of the along-wind, cross-wind, and vertical velocity components
m

Coh_u, Coh_v, Coh_w
Spatial co-coherence of the along-wind, cross-wind, and vertical velocity components 
-

Coh_hor
Spatial co-coherence of the horizontal wind speed
-

kd
Normalized wavenumber vector for the coherence estimates
-

d_y
Lateral separation distance
m

d_z
Vertical separation distance
m

y
Lateral coordinate
m

z
Vertical coordinate (measurement height)
m

TSA
Time-series availability after filtering
-

Stationarity
1st and 2nd order stationarity of mean wind speed and direction(relative error between moving and and global mean/STD)
-

AD8
Relative operating time of the AD8-180 wind turbine on the test site
-

Literature related to the dataset

[1] Vogt, L., Gottschall, J., and Jakobsen, J. B.: Turbulence characterization in near-coastal environment using triple short-range lidars and mast anemometry, Wind Energ. Sci. Discuss. [preprint], https://doi.org/10.5194/wes-2026-100, in review, 2026.[2] Vogt, L., Gottschall, J., and Jakobsen, J. B.: Vertical and Lateral Wind Coherence Estimation Using Three Synchronized Continuous-Wave Lidars, J. Phys.: Conf. Ser., https://doi.org/10.1088/1742-6596/3224/2/022001, 2026.

Acknowledgements

This work was partially funded by the Research Council of Norway through the Large Offshore Wind Turbines (LOWT) project (RCN 325294). Measurement data were previously obtained as part of the projects HighRe (ref. no. 03EE2001) and Testfeld BHV (ref. no. 0324148) funded by the German Federal Ministry for Economic Affairs and Energy (BMWE) on the basis of a decision by the German Bundestag. The sonic anemometer data were post-processed and documented by Paul Meyer. Ashim Giyanani reconstructed the turbulent wind components from the WindScanner measurements in collaboration with Mikael Sjöholm and Gunhild Rolighed Thorsen from DTU Wind and Energy Systems.