Abstract
Accurate description of the wind energy resource in the coastal zone is crucial for countries developing near-shore wind farms. The RUNE experiment aims to use lidar measurements and mesoscale modelling to study the behaviour of the flow in the coastal zone and find the most effective way to estimate the near-shore wind resource. In this report we document all information regarding the measurement systems and the coastal campaign.
The wind speed is estimated from radial velocities measured by a lidar in sector-scanning mode, from two lidars performing dual-overlapping scans and from five vertical profiling lidars, of which one was operating offshore on a floating platform. All these instruments are inter compared, showing generally good agreement. The availability is best for the vertically profiling lidars, followed by the sector-scan setup, the dual setup and the lidar buoy. We have also reference measurements from the meteorological mast at Høvsøre some kilometers south of the campaign’s site.
The wind climate during the campaign is characterized by strong westerlies with occasional storms. The measurements from the vertically profiling lidars agree well with those from the meteorological mast and show a decrease of mean wind speed from west to east. Two lidars (a long- and a short-range system) measuring next to each other measured similar winds speeds, although the wind speed from the long-range lidar had a small positive bias. There was also a positive bias in the mean wind speed from the sector-scan at large measuring distances.
Satellite winds from ASCAT, Sentinel-1 and TerraSAR-X were available. ASCAT were of coarse resolution and were not used for any direct comparisons with the lidar measurements. A spatial average of these SAR wind speeds along the coast was compared with coinciding scanning lidar 10 min wind speeds.TerraSAR-X retrieved winds showed a rather large deviation from the lidar wind speed transects extrapolated to 10 m. Sensitivity tests performed on the methods for the wind speed retrieval showed small differences in the statistics for the different combinations of the spatial resolution and the polarisation ratio. For the cases investigated, the wind direction from the model was not differing by more than 15o compared to the dual setup, but the spatial variability was not captured.
The wind speed is estimated from radial velocities measured by a lidar in sector-scanning mode, from two lidars performing dual-overlapping scans and from five vertical profiling lidars, of which one was operating offshore on a floating platform. All these instruments are inter compared, showing generally good agreement. The availability is best for the vertically profiling lidars, followed by the sector-scan setup, the dual setup and the lidar buoy. We have also reference measurements from the meteorological mast at Høvsøre some kilometers south of the campaign’s site.
The wind climate during the campaign is characterized by strong westerlies with occasional storms. The measurements from the vertically profiling lidars agree well with those from the meteorological mast and show a decrease of mean wind speed from west to east. Two lidars (a long- and a short-range system) measuring next to each other measured similar winds speeds, although the wind speed from the long-range lidar had a small positive bias. There was also a positive bias in the mean wind speed from the sector-scan at large measuring distances.
Satellite winds from ASCAT, Sentinel-1 and TerraSAR-X were available. ASCAT were of coarse resolution and were not used for any direct comparisons with the lidar measurements. A spatial average of these SAR wind speeds along the coast was compared with coinciding scanning lidar 10 min wind speeds.TerraSAR-X retrieved winds showed a rather large deviation from the lidar wind speed transects extrapolated to 10 m. Sensitivity tests performed on the methods for the wind speed retrieval showed small differences in the statistics for the different combinations of the spatial resolution and the polarisation ratio. For the cases investigated, the wind direction from the model was not differing by more than 15o compared to the dual setup, but the spatial variability was not captured.
| Original language | English |
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| Publisher | DTU Wind Energy |
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| Number of pages | 33 |
| ISBN (Print) | 978-87-93278-72-1 |
| Publication status | Published - 2016 |
| Series | DTU Wind Energy E |
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| Number | 0115 |