Abstract The value of foF2, critical frequency of the F2 region, determines to a large extent, the usable frequency spectrum for HF communications. For a long-time a linear relation between foF2 and smoothed sunspot numbers formed the basis of all ionospheric predictions (CCIR-340) for all local times, locations and seasons. IGY data, however, showed that depending on location, local time and season, this relation is not fully linear. A second degree polynomial represented the relationship more closely. Taking account of the variable character of the relationship, orthogonal polynomials were found convenient in view of changing the order of polynomials. For four low latitude stations it could be shown that beyond their statistical character our results are associated with chemical and dynamical changes taking place in the upper atmosphere, and with subsequent changes in the ionosphere.
Use of orthogonal polynomials for correlating F-region parameters with sunspot numbers for prediction purposes
Advances in Space Research ; 8 , 4 ; 165-172
1988-01-01
8 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Comparative study of different solar parameters with sunspot numbers
Online Contents | 2005
|Sunspot numbers during 1736–1739 revisited
Online Contents | 2007
|Sunspot numbers during 1736–1739 revisited
Elsevier | 2007
|Phase asynchrony between coronal index and sunspot numbers
Elsevier | 2012
|Phase asynchrony between coronal index and sunspot numbers
Online Contents | 2012
|