Low-latitude Middle Atmospheric Dynamics

The work mainly deals with background wind and temperature variations of tropical middle atmosphere with main focus on mesosphere. The work has been carried out using long term observations of Indian MST Radar, Lidar, Rocket soundings and satellite observations such as High Resolution Doppler Imager (HRDI) aboard Upper Atmosphere Research Satellite (UARS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) aboard Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED). Tropical mesospheric echo occurrence and the possible source mechanisms of the echoes are discussed. Importantly, for the first time non-linear interaction between mesospheric semiannual oscillation (MSAO) and mesospheric quasi biennial oscillation (MQBO) are reported.