Rayleigh‐Brillouin scattering in the atmosphere and in the lab

Abstract

The global observation of atmospheric wind profiles remains to be the highest priority need for weather forecast. Therefore, the European Space Agency ESA decided to implement the Atmospheric Dynamics Mission ADM-Aeolus to demonstrate the potential of the Doppler lidar technology for global wind profiling. Thereby, the laser of the Doppler lidar sends short pulses into the atmosphere where they are scattered by aerosols and molecules. Some of the backscattered light is collected by a telescope and analyzed concerning its frequency. The frequency shift between emitted and received light, caused by the Doppler shift of moving particles, is directly proportional to the atmospheric wind speed. The accuracy of this measurement technique is significantly depending on the knowledge of the spectral distribution of the backscattered light. For the validation and the improvement of spectral line shape models of Rayleigh-Brillouin scattered light, laboratory measurements at the university of Amsterdam as well as atmospheric measurements from Germany highest mountain – the Zugspitze were performed. In my talk I will introduce the Doppler lidar principle and demonstrate the urgent need of accurate line shape description of the scattered light. The results of laboratory and atmospheric measurements are introduced and discussed.