Nighttime and sunrise variations of absorption
Article first published online: 7 DEC 2012
Copyright 1974 by the American Geophysical Union.
Volume 9, Issue 12, pages 1101–1108, December 1974
How to Cite
1974), Nighttime and sunrise variations of absorption, Radio Sci., 9(12), 1101–1108, doi:10.1029/RS009i012p01101.(
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Revised: 5 JUL 1973
- Manuscript Received: 23 AUG 1971
The average behavior of the MF A1 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 Es 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.