dc.contributor.author |
Sastri, J. H |
|
dc.contributor.author |
Sasidharan, K |
|
dc.contributor.author |
Subramanyam, V |
|
dc.contributor.author |
Srirama Rao, M |
|
dc.date.accessioned |
2009-11-13T12:47:49Z |
|
dc.date.available |
2009-11-13T12:47:49Z |
|
dc.date.issued |
1979-09 |
|
dc.identifier.citation |
Annales De Geophysique, Vol. 35, No. 3, pp. 153 - 158 |
en |
dc.identifier.issn |
0011-3891 |
|
dc.identifier.uri |
http://hdl.handle.net/2248/4907 |
|
dc.description.abstract |
Using ionogram data at Kodaikanal (geomagnetic lat. 06 deg N, Dip 3.5 deg N) over a seven year period, Jan. 1957-Dec. 1963, a study is made of the seasonal and sunspot cycle variations in the nocturnal occurrence of amplitude and frequency type of spread-F configurations. It is found that the occurrence of both amplitude and frequency type spread-F exhibits a positive dependence on the phase of the sunspot cycle. There is also a significant positive correlation between the occurrence patterns of amplitude and frequency type spread-F. The occurrence of amplitude type spread-F shows a prominent peak around 20-22 hrs LT, irrespective of season and phase of the sunspot cycle, except during local summer months of low sunspot years when it is shifted to the postmidnight period around 00-03 hrs LT. The peak occurrence of amplitude spread-F (for two hours around the peak) shows a semi-annual variation during years of moderate and low sunspot activity. A comparison of these results with those at other equatorial stations revealed a marked longitudinal dependence of the characteristics (nocturnal, seasonal and sunspot cycle changes) of amplitude and frequency type spread-F. |
en |
dc.language.iso |
en |
en |
dc.publisher |
European Geophysical Society |
en |
dc.subject |
Equatorial Atmosphere |
en |
dc.subject |
Nocturnal Variations |
en |
dc.subject |
Solar Activity Effects |
en |
dc.subject |
Solar Terrestrial Interactions |
en |
dc.subject |
Spread F |
en |
dc.subject |
Annual Variations |
en |
dc.subject |
Ionograms |
en |
dc.subject |
Sunspot Cycle |
en |
dc.title |
Range and frequency spread-F at Kodaikanal |
en |
dc.type |
Article |
en |