Abstract
It is shown that the use of initial data series of different lengths is one of the main causes of the difference in the values of trends in the F2-layer parameters, foF2 and hmF2, obtained in a series of publications of the authors and published by other researchers. Arguments are presented in favor of the statement that systematic changes in the F2 layer began around 1980. Searching for trends, the authors consider periods after 1980. At the same time the majority of other scientists use the entire available array of data beginning in 1957 and 1958 (and sometimes even earlier) to search for trends. In that case, the analyzed time interval automatically includes the period before 1980, when the trends were absent. This leads to a substantial underestimation of the magnitude of the obtained negative trends in foF2 and hmF2. Particular examples based on the data of both the authors and other scientists confirming the statement are presented.
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Original Russian Text © A.V. Konstantinova, A.D. Danilov, 2015, published in Geomagnetizm i Aeronomiya, 2015, Vol. 55, No. 3, pp. 361–369.
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Konstantinova, A.V., Danilov, A.D. Choice of series of initial data in deriving trends in the ionospheric F2-layer parameters. Geomagn. Aeron. 55, 344–352 (2015). https://doi.org/10.1134/S0016793215030111
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DOI: https://doi.org/10.1134/S0016793215030111