The belt of equatorial spread-F
Date
1960Author
Lyon, AJ
Skinner, NJ
Wright, RWH
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
The morphology of the belt of equatorial spread-F at sunspot maximum is investigated, using I.G.Y. data, for magnetically quiet and magnetically disturbed conditions respectively. The belt is found to extend from about 30°S to 30°N in magnetic latitude and to have a region of very high incidence, exceeding 90 per cent for the early part of the night, about 20° wide in latitude and centred on the dip equator. In Africa and India there is little seasonal variation in quiet-day incidence, but a marked seasonal variation occurs in the American zone where there is a pronounced minimum in local winter. Throughout the whole belt from 30°S to 30°N there is a strong inverse correlation between spread-F incidence and magnetic activity. Moreover the post-sunset rise of the base of the layer, which usually precedes the onset of spread-F shows a marked positive correlation with spread-F incidence within the belt. No existing theory seems adequate to account for all of these facts but it seems likely that hydromagnetic disturbances are involved.
URI
http://www.sciencedirect.com/science/article/pii/002191696090043Xhttp://hdl.handle.net/11295/65475
Citation
Lyon, A. J., Skinner, N. J., & Wright, R. W. H. (1960). The belt of equatorial spread-F. Journal of Atmospheric and Terrestrial Physics, 19(3), 145-159.Publisher
University of Nairobi