Atmospheric waves in the ionosphere due to total solar eclipse

Abstract

CHIMONAS¹ predicted that the ‘cooling spot’ of the lunar shadow of an eclipse, which travels at supersonic speeds through the atmosphere, is a continuous source of atmospheric gravity waves. These gravity waves show up by their interaction with the ionosphere and can be detected using standard radio techniques. Total electron content measurements² in the USA at a distance of several thousand km from the path of totality, detected oscillations which were attributed to a solar eclipse in agreement with the theory of Chimonas³. Measurements made during the 1973 central African eclipse⁴ failed to detect any oscillations, although these results may have been obscured by the occurrence of a magnetic storm at the same time. We present here the results of measurements made on the angle of arrival of a high frequency radio wave inside the path of totality of an eclipse, which took place on 23 October 1976.