Causative mechanisms for the occurrence of a triple layered mesospheric inversion event over low latitudes

摘要: The temperature profile obtained from the space borne instrument “Sounding of Atmosphere by Broadband Emission Radiometry” onboard “Thermosphere Ionosphere Mesosphere Energetics and Dynamics” shows a triple layered mesospheric inversion event on night 23 September 2011, when there is an overpass near low-latitude sites Gadanki (13.5°N, 79.2°E) Tirunelveli (8.7°N, 77.8°E). three layers (MILs) are formed in height region around ~70 (lower), ~80 (middle), ~90 km (upper) with amplitudes ~11, ~44, ~109 K thickness 3.4, 4.9, 6.6 km, respectively. formation lower middle MILs can only be observed Rayleigh lidar profiles over due to upper limitation system. Nearly all dominant causative mechanisms examined for occurrence MIL event. at ~70 km inferred planetary wave dissipation, as sudden decrease activity above 70 km. Further, it demonstrated that ~80 km turbulence generated gravity breaking which turn wave-semi-diurnal tidal interaction, though descends rate ~1 km/h, nearly vertical phase speed diurnal tide, whereas 90 km large chemical heating (~45 K/day) exothermic reaction O + O + M → O2 + M.