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My Research Interests


                                                   
(a) The study of the impact of meteor shower on sodium airglow has been initiated to investigate. Meteoric ablation is believed to be the major source for the formation of upper mesospheric sodium and the other metal layers in this region of the atmosphere. As meteors enter the atmosphere, they ablate and leave debris in their path. This ablation typically occurs near altitudes of 80 to 100 km, where the average temperature of the atmosphere allow the metal atoms to be freed. The input of sodium atoms from the meteors causes the rearrangement of the sodium layers. Continuous monitoring of it will reveal the abundances as well as the origin of the neutral sodium atoms.

(b) As discussed earlier, airglow photometry can be used as a tool to understand the wave dynamics. The propagation of Atmospheric Gravity Waves (AGW) causes oscillation in the sodium layer. Simultaneous measurement of sodium lidar and sodium photometer will characterize the vertical parameter of AGW. The horizontal parameter of AGW will be characterized by the CCD based multi-wavelength airglow imager. Combining the imager and Na lidar observations, the three dimensional AGW will be characterized.

(c) AGW is the one which couples the mesosphere and thermosphere-ionosphere. It originates from lower atmosphere and propagate upward. Some of the modes of AGW has the phase velocity equal to the mean velocity of the ambient wind at the mesospheric altitude. These modes are absorbed but others get leaked through mesosphere and reach at ionosphere altitude. There they act as a seed perturbation of Equatorial Spread F (ESF). The development of ESF has been studied extensively. But several issues need more investigations.
Another issue is the decaying phase of ESF, which is not properly understood. Attempts will be made to record the decaying phase of ESF using the simultaneous measurements of VHF radar and 630.0 nm airglow emission line.