Temperature measurement by rotational Raman lidar

Marie-Lise Chanin (1) , Alain Hauchecorne (1) , Dusan Nedeljkovic (1)

1 SA - Service d'aéronomie

Sounding of the atmospheric temperature by lidar has mostly been limited to Rayleigh scattering operating from 30 km up. The vibrational Raman scattering has been developed to extend the measurements down, but this technique does not allow accurate measurements in the presence of a large quantity of volcanic aerosols, as is the case now after the Pinatubo eruption, and in the presence of PSCs or cirrus clouds. The newly developed rotational Raman technique uses two wavelengths very close to each other and close to the Rayleigh and Mie backscattered light, which makes it technically difficult, but also independent of the extension coefficient. For this purpose we use a combination of molecular nitrogen and oxygen rotational Raman lines using the fact that the ratio of their intensities is sensitive to temperature. Results obtained with this technique agree with radiosondes within 0.5 K between ground and 20 - 25 km. Recent campaigns have shown the insensitivity of the technique to the high load of volcanic aerosols which are now observed above the French site of OHP (44 degree(s)N, 6 degree(s)E).

Domaines: Physique Atmosphérique et Océanique [physics.ao-ph]

Marie-Lise Chanin, Alain Hauchecorne, Dusan Nedeljkovic. Temperature measurement by rotational Raman lidar. Proc. SPIE Vol. 1714, Lidar for Remote Sensing. Environmental Sensing '92, 1992, Berlin, Germany, Jun 1992, Berlin, Germany. pp.242-250, ⟨10.1117/12.138532⟩. ⟨insu-03598695⟩