A 22-year cycle in the F layer ionization of the ionosphere
Item
Title (Dublin Core)
A 22-year cycle in the F layer ionization of the ionosphere
Description (Dublin Core)
The double-sunspot-cycle variation in terrestrial magnetic activity has been well known for about 30 years. In 1990 we examined and compared the low-solar-activity (LSA) part of two consecutive cycles and predicted from this database and from published results the existence of a double-sunspot-cycle variation in total electron content (TEC) of the ionosphere too. This is restricted to noontime when the semi-annual component is well developed. Since 1995 we have had enough data for the statistical processing for high-solar-activity (HSA) conditions of two successive solar cycles. The results confirm the LSA findings. The annual variation of TEC shows a change from an autumn maximum in cycle 21 to a spring maximum during the next solar cycle. Similar to the <i>aa</i> indices for geomagnetic activity the TEC data show a phase change in the 1-year component of the Fourier transform of the annual variation. Additionally we found the same behaviour in the F-layer peak electron density (<i>N<sub>max</sub></i>) over four solar cycles. This indicates that there exists a double-sunspot-cycle variation in the F-layer ionization over Europe too. It is very likely coupled with the 22-year cycle in geomagnetic activity.
Creator (Dublin Core)
Feichter, E.
Leitinger, R.
Date (Dublin Core)
2018-09-27
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.1007/s00585-997-1015-0
https://angeo.copernicus.org/articles/15/1015/1997/
Source (Dublin Core)
eISSN: 1432-0576
Language (Dublin Core)
eng
