New Dynamic Aspects of Intertropical F2 Ionization
Article first published online: 7 DEC 2012
Copyright 1971 by the American Geophysical Union.
Volume 6, Issue 11, pages 945–956, November 1971
How to Cite
1971), New Dynamic Aspects of Intertropical F2 Ionization, Radio Sci., 6(11), 945–956, doi:10.1029/RS006i011p00945.(
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Received: 1 AUG 1969
Diurnal changes in F2 ionization distribution as measured during June and July 1966 over the Tamanrasset meridian reveal two types of asymmetric phenomena distorting the crest-and-trough system (formerly known as the equatorial F2 ionization anomaly). The first type corresponds to a general time variation of the latitude asymmetry. Our observations yield four independent parameters of this asymmetry; for 80% of the time, the variation can be attributed to ion drag due to a time-varying meridian air wind. Magnetic activity is correlated with the amplitude of this wind, and the low-altitude thermospheric circulation is discussed. Day-to-day fluctuations of the diurnal evolution pattern suggest a possible long-term control of the equatorial electric field by the general dynamo current system. A second type of asymmetry shows more intense, local, and short-lived phases superimposed on the fountain and neutral wind fluctuations. It has the character of a transitory forced-diffusion process. We believe that the factor responsible is electron temperature gradients produced by conjugate photoelectron heating.