Abstract
A good knowledge of the temperature field and its variability in the middle atmosphere isneeded to understand the causes of its natural variability and to estimate the possible impact ofanthropogenic perturbations. Rayleigh-Raman lidars provide a powerful tool to reach thisgoal. Rayleigh backscattering of a laser beam by atmospheric molecules allows to measure densityand temperature profiles above 30 km. The network of Rayleigh lidars has shown thepotential of this method and has been used during the past 15 years to obtain new results concerningthe structure and the climatology of the middle atmosphere and to validate satellitemeasurements. Recent improvements in lidar techniques allow to extend downwards thetemperature profiles into the lower stratosphere and the upper troposphere using vibrationaland rotational Raman scattering by the main gases of the atmosphere, O2 and N2.
