Part II - Continuous Observations
|Introduction |||Surface Layer |||Boundary layer profiling |||Sky monitoring |||Aerosol size measurements|
Boundary layer profiling
Wind profilers (sodar, UHF, VHF)
At site 1, the combinaison of a sodar (MAG, measuring the wind from 10 m to 300 m a.g.l), UHF profiler
(LA, measuring the wind from 200 m to 3000 m a.g.l) and a VHF profiler (LA, measuring the wind from
1.5 km to 16 km a.g.l) is covering the whole atmospheric column.
The sodar is mobile, and will potentially be moved for some IOPs at the entrance of the main valley nearby, for the knowledge of the wind reversal in this valley.
A network of 3 profilers (LA UHF in site 1, CNRM UHF in site 2, and LPCA sodar in site 3 at Capvern) will enable to estimate the 3D wind at the scale of the Plateau. Both the UHF and the sodar profiling systems can also measure some characteristics of the atmospheric turbulence. The UHF wind profiler also gives estimates of the height of boundary layer top inversion, or of other strong vertical gradients in the atmosphere.
In collaboration with LMD-IPSL, a LEOSPHERE Doppler lidar (Windcube 200) has been operated in site 1 during the BLLAST experiment. It measured the vertical velocity of the wind at high temporal (5 s) and vertical (50 m) resolutions. This enables us to make wind vertical velocity statistics, to analyse the structure of the thermals and calculate the vertical velocity integral scales and the intensity of turbulence during the afternoon transition.
There will be one aerosol lidar on each of site 1 (LPCA) and site 2 (CNRM/GAME), monitoring the aerosol backscatter structure continuously during BLLAST.