  The vertical structure of temperature observed by SABER (Sounding of
Atmosphere using Broadband Emission Radiometry) aboard TIMED (Thermosphere,
Ionosphere, Mesosphere Energetics and Dynamics) and sprites observations made
during the Eurosprite 2003 to 2007 observational campaign were analyzed. Sprite
observations were made at two locations in France, namely Puy de Dome in the
French Massif Central and at the Pic du Midi in the French Pyrenees. It is
observed that the vertical structure of temperature shows evidence for a
Mesospheric Inversion Layer (MIL) on those days on which sprites were observed.
A few events are also reported in which sprites were not recorded, although
there is evidence of a MIL in the vertical structure of the temperature. It is
proposed that breaking gravity waves produced by convective thunderstorms
facilitate the production of (a) sprites by modulating the neutral air-density
and (b) MILs via the deposition of energy. The same proposition has been used
to explain observations of lightings as well as both MILs and lightning arising
out of deep convections.
