Vertical soundings at Ahmedabad during partial solar eclipse on 14th December 1955

Abstract

The results of vertical ionospheric soundings at Ahmedabad during the partial (magnitude 47%) solar eclipse on 14th December 1955 are discussed. The critical frequency of the E layer on control days varied according to the law ƒ_oE=k cosⁿ X, k and n having the mean values 4.06 Mc./s. and 0.37 respectively. The variation of ƒ_oE during eclipse period was roughly consistent with that of Chapman Layer with a recombination coefficient of about 0.8 × 10^-8 cm.³ sec.^-1 The critical frequencies of E₁, E₂ and F₁ layers decreased during eclipse, though the variations were irregular. The percentage deviation of ƒ₀F₂ on the eclipse day from the control day values showed a minimum at about the middle of the eclipse period. There were indications of the formation of ƒ_1.5 during the latter part of the eclipse. Semi-thickness of the F₂ layer had increased during the eclipse period. Sporadic E layer was not affected by the eclipse.