Doppler lidar measurements at Mace Head
Carrier-to-noise ratio (CNR) at line-of-sight measurement pointing to zenith. |
Vertical wind speed (radial wind at line-of-sight measurement pointing to zenith). |
Horizontal wind speed. |
Wind from direction: 0 and 360 degrees = North (wind coming from North). |
Vertical wind shear from horizontal wind speed per 100 m altitude. |
Vertical wind shear from horizontal wind direction (or wind veer) per 100 m altitude. |
Horizontal wind speed (colour) and direction(arrows). Arrows point to where the wind is going. |
Logarithm of eddy dissipation rate (EDR) from VAD at 15 degrees elevation. |
Horizontal wind speed (at 15 degrees elevation) and height of low level jet. |
Horizontal wind speed profiles and low level jets (LLJ). |
The Doppler lidar at Mace Head is a WindCube 200S (manufacturer Leosphere). It emits at 1.54 µm and measures the intensity of backscattered light as well as the Doppler shift of the detected radiation. From the deviation of the detected wavelength from the emitted one, profiles of the radial wind can be determined. Subsequently, the radial wind is converted into profiles of the three wind components.
The horizontal wind speed and the wind direction are derived using a least squares fit of the radial wind during full conical scans (VAD). The goodness of the fit is influenced by clouds and wind velocity. This may cause gaps in the plots, where quality screening removed invalid fit results. Results from other VAD scan angles.
The wind measurements depend on the presence of scatterers in form of cloud droplets or aerosol particles. The lidar therefore is also suited for the detection of aerosol layers, like volcanic ash plumes. The WindCube is a scanning lidar and therefore does not only produce one vertical profile, but can also be used to monitor the horizontal distribution of aerosols and clouds.
Low level jet (LLJ) detection by Tuononen, et al. (2017). LLJs are peaks in the profiles of horizontal wind speed retrieved from full conical scans (VAD) at 15 degrees elevation.
The pictures shown here are updated every hour. Data are not quality assured.
The Remote Sensing Division of the Mace Head Atmospheric Research Station is run by the Centre for Climate & Air Pollution Studies (C-CAPS) at NUI Galway and supported by Irish Environmental Protection Agency (EPA), Irish Aviation Authority (IAA), and Science Foundation Ireland (SFI). Remote Sensing at Mace Head also benefits from involvement in Cloudnet; European Research Infrastructure for the observation of Aerosol, Clouds, and Trace gases ACTRIS and ACTRIS-2 (grant agreement numbers 262254 and 654109); European FP7 collaborative project BACCHUS (Impact of Biogenic versus Anthropogenic emissions on Clouds and Climate: towards a Holistic UnderStanding, grant agreement number 603445); and COST action ES1303: TOPROF (Towards operational ground based profiling with ceilometers, doppler lidars and microwave radiometers for improving weather forecasts) supported by COST (European Cooperation in Science and Technology).