[P-EM12] Coupling Processes in the Atmosphere-Ionosphere System

[PEM12-P23] Development of a resonance scattering lidar for simultaneous observation of meteoric metal atom and ion layers

*Mitsumu K. Ejiri^1,2, Masayuki Katsuragawa³, Ayaka Hashimoto³, Sota Kobayashi³, Takuo T. Tsuda³, Takuji Nakamura^1,2 (1.National Institute of Polar Research, 2.The Graduate University for Advanced Studies, SOKENDAI, 3.The University of Electro-Communications)

Keywords:The mesosphere and thermosphere, Resonance scattering lidar observation, Calcium atom and ion layers

In a transition region between neutral atmosphere and geospace plasma (80 - 500 km), vertical mass transport processes have still to be revealed because simultaneous measurement of neutral atmosphere and plasma is quite difficult. There are meteoric metal atoms and ions with a long chemical lifetime in this region. Calcium is the only metal that can be observed both of atom (Ca) and ion (Ca⁺) by ground-based resonant scattering lidar observations. To measure temporal variation in vertical density distributions of Ca and Ca⁺ ion, as a dynamical tracer in this region, and investigate the vertical mass transport, we are developing a resonance scattering lidar for simultaneous observation of Ca and Ca⁺ ion. The lidar system has an injection-locked Ti:Sapphire laser with a broad frequency tunability as a transmitter and receives the resonance scatter signals by a telescope with ~80cm diameter. The laser oscillator is designed that can be tuned to the resonance lines of Ca and Ca⁺ ion. We successfully receive the signals from each layer while a development for simultaneous observation is still ongoing. In this presentation, we will introduce the new lidar system and show some preliminary results of test observations.