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A New Method of Obtaining an lonospheric Index of Solar Activity From the F 2 Layer Critical Frequencies
Author(s) -
Chun-ming Huang
Publication year - 1967
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1002/rds196725467
Subject(s) - ionosphere , standard deviation , index (typography) , residual , mathematics , standard error , critical frequency , statistics , quadratic equation , meteorology , atmospheric sciences , physics , computer science , algorithm , geometry , geophysics , world wide web
A new method of obtaining an ionospheric index of solar activity, based on the monthly median foF 2 at 4 hours of the day (0, 6, 12, and 18 local hours), is described. The index for each month of the year has beeh determined, together with regression coefficients of quadratic equations for every hour at several typical stations, by minimizing the standard percentage error of foF 2 estimates. The index has favorable features: the standard deviation of index above and below its running average is smaller; the standard percentage deviation of residual of foF 2 and the standard percentage deviation of total error in forecasts of foF 2 are much smaller than those of the index obtained by the current method for calculating an ionospheric index of solar activity. Reasons for considering the new index a better approximation to an ideal solar index for the ionosphere are presented.