I. Quiet ionosphere.
The Lunar Tide in ƒbEs
Article first published online: 7 DEC 2012
Copyright 1971 by the American Geophysical Union.
Volume 6, Issue 2, pages 191–196, February 1971
How to Cite
1971), The Lunar Tide in ƒbEs, Radio Sci., 6(2), 191–196, doi:10.1029/RS006i002p00191., and (
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Received: 1 OCT 1970
Hourly measurements of the blanketing frequency of sporadic E(ƒbEs) made during the years 1958 through 1965 have been analyzed for lunar daily variations. The data, which came from ten stations, were analyzed by the Chapman-Miller method. Both seasonal and yearly average lunar variations were obtained. The lunar semidiurnal oscillations in ƒbEs ranged from 0.01 to 0.04 MHz, with maximums occurring from 7 to 9 hours lunar time. The amplitude of the lunar tide in ƒbEs is an order of magnitude less than the lunar variations of ƒ0Es. Since ƒbEs is close to the plasma frequency of Es, the oscillation in ƒbEs represents a lunar variation in the electron density of Es layers, whereas the significance of the lunar variation of ƒ0Es is not clear. The phases of the lunar tides in ƒbEs, ƒ0Es, and h′Es are found to be nearly the same. Two sources of lunar influence on Es electron density are considered (1) wind shears in the lunar tide acting to augment or decrease the wind shears responsible for E8, and (2) interaction of E8 with electrostatic fields associated with the lunar current system.