Daytime lidar measurements of the sodium layer in China

Metal layers are formed owing to the deposition of metal species, such as, Na, Fe, Ma, Si, Ca, and K, in the mesosphere and lower thermosphere region. The metal species come from the meteor ablations when meteors enter into the atmosphere (Plane, 1991). Among these species, Na can be easily detected by sodium lidar since it has enough abundance and large backward scattering cross-section. On the other hand, the chemical lifetime of the sodium layer is longer

Metal layers are formed owing to the deposition of metal species, such as, Na, Fe, Ma, Si, Ca, and K, in the mesosphere and lower thermosphere region. The metal species come from the meteor ablations when meteors enter into the atmosphere （Plane, 1991）. Among these species, Na can be easily detected by sodium lidar since it has enough abundance and large backward scattering cross-section. On the other hand, the chemical lifetime of the sodium layer is longer than one day in the main sodium layer （85-100 km） and thus can be employed as a dynamical tracer for atmospheric perturbations （Xu et al., 2003）.