Atmospheric waves induced by the solar eclipse of 30 June 1973.

Results are reported of ionospheric sounding and polarization rotation measurements made at a series of stations across West Africa during the total solar eclipse of 30 June 1973. A weak ionospheric disturbance identified by a minimum in both peak density and total electron content appears to be associated with the eclipse, propagating over a limited distance in the form of a bow wave. A small wave of period 18 min may also be eclipse produced, the wavelength being comparable to the size of the umbral region. Possible mechanisms for the generation of atmospheric waves and ionospheric disturbances by an eclipse are discussed but no firm conclusion has been reached concerning the source of the observed fluctuations.