Biosphère Climat

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Today, our capacity to observe the temperature profile is either continuous but limited to the surface layer (tower, tethered balloon), or offers good vertical coverage but sporadic over time (radiosondes, drone or other airborne carrier). The lidar has the possibility of making continuous measurements of the surface until the tropopause with high spatial and temporal resolution (50 m, 10 s) and also has the potential to quantify turbulent parameters (variance, scales, flux) .

The TERA lidar consists of an Nd: YAG laser tripled in frequency emitting 160 mJ / 30 Hz at 355 nm, a telescope 50 cm in diameter and a monochromator with two temperature channels, a water vapor channel and an elastic path for detection. A large scanner allows three-dimensional measurements. In 2018, the TERA lidar is in the laboratory testing phase.

Figure 1 Instrumental diagram of the Lidar TERA under development at LMD
IF : interference filter;  BS : spectral separator;  ND : optical density;  RR : rotational raman;  PMT : photomultiplier

Figure 2 Photograph of Lidar TERA during atmospheric test at LMD