Abstract:
Solar eclipse provides a rare opportunity to study the interaction between solar irradiances with
the terrestrial atmosphere. There are different types of solar eclipses such as, total solar eclipse,
partial solar eclipse, annular solar eclipse and hybrid solar eclipse. Solar eclipse occurs when
the Moon passes partially or fully in front of the Sun, which casts a shadow over a certain area
of the Earth and the formation of gravity wave structure induced by cooling of the atmosphere.
The objective of this study is to investigate the changes in the altitudinal distribution of temperature,
ozone mixing ratio, hydroxyl emission volume and chemical heating rate on the middle
atmosphere region (30-80 km) during the hybrid solar eclipse occurred on 03 November 2013 using
the SABER (Sounding of the Atmosphere using Broad Emission Radiometry) instrument on
board the TIMED (Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics) satellite.
Although various studies have been carried out on the effects of solar eclipse on lower atmosphere
at different latitudes, yet there are limited studies on middle atmosphere at tropic latitude.
The present work is therefore the first of its kind in African sector particularly in using SABER
satellite data. The results of this study reveals that a cooling of the order of -5 to -10K in the mesospheric
region during eclipse day. The supersonic motion of the Moon’s shadow (cooling spot)
is believed to be the reason for the raised gravity wave activity induce solar eclipse. The brunt
vaisala frequency square (N2) indicates a convective instability around 75 km and consequently
breaking of gravity waves leads to the disturbance in the concentration chemical constituents.