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Nighttime and sunrise variations of absorption
Author(s) -
Ganguly S.
Publication year - 1974
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs009i012p01101
Subject(s) - sunrise , absorption (acoustics) , midnight , sunset , atmospheric sciences , diurnal temperature variation , environmental science , meteorology , physics , optics , astronomy
The average behavior of the MF A 1 absorption data at night and sunrise times at Calcutta has been described with a view to understanding the maintenance of the nighttime absorbing region. The nighttime variation of absorption which attains a minimum around one hour after local midnight could easily be accounted for in terms of the scattered UV fluxes. A small decrease in absorption before sunrise is evidenced. The analysis using the partially reflecting E s echo suggests this is caused by a decrease in deviative loss at F ‐region heights. The onset time for a further increase in absorption agrees very well with that observed from other techniques.