Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2019, Vol. 16, No. 2, pp. 269-272
Trend in the ionospheric F2 region over Novosibirsk in 23rd and 24th solar cycles
1 A.A. Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, Russia
Accepted: 25.03.2019
DOI: 10.21046/2070-7401-2019-16-2-269-272
The purpose of this study is to analyze the time series of the critical frequency of the ionospheric F2 region over Novosibirsk. We have considered a median values and constructed the array of minimum and maximum daily values for each month of the year for 23rd and 24th solar cycles. The values of the radio emission flux 10.7 cm was taken into account. The obtained results provide some evidence of differences in the trends of ionosphere condition in the solar cycles under consideration. It is shown that trends most significantly depend on solar activity and can differ numerically several times for different solar cycles. It is established that the variations of maximum values of foF2 make a bigger contribution to the trends of the ionospheric F2 region regardless of an order of the solar cycle. Calculations of trends depend on geomagnetic coordinates of places of observation and therefore the research needs to be continued for other stations to estimate the received results for the whole globe.
Keywords: trend, ionosphere, solar cycle
Full textReferences:
- Danilov A. D., Vanina-Dart L. B., Parametry ionosfernogo sloya F2 kak istochnik informatsii o trendakh dinamiki termosfery (Parameters of the ionospheric F2 layer as a source of information on trends in thermospheric dynamics), Geomagnetizm i aeronomiya, 2010, Vol. 50, No. 2, pp. 1–14.
- Danilov A. D., Critical frequencies foF2 as an indicator of trends in thermospheric dynamics, J. Atmospheric and Solar-Terrestrial Physics, 2009, Vol. 71, No. 13, pp. 1430–1440.
- Danilov A., New results in studying foF2 trends, J. Atmospheric and Solar-Terrestrial Physics, 2017, Vol. 163, pp. 103–113.
- Elias A. G., Possible Sources of Long-Term Variations in the Mid-Latitude Ionosphere, The Open Atmospheric Science J., 2011, No. 5, pp. 9–15.
- Lastovicka J., Global pattern of trends in the upper atmosphere and ionosphere: recent progress, Atmospheric and Solar-Terrestrial Physics, 2009, Vol. 71, pp. 1514–1528.
- Lastovicka J., Akmaev R. A., Beig G., Bremer J., Emmert J. T., Jacobi C., Jarvis M. J., Nedoluha G., Portnyagin Y. I., Ulich T., Emerging pattern of global change in the upper atmosphere and ionosphere, Annales Geophysicae, 2008, Vol. 26, No. 5, pp. 1255–1268.
- Mielich J., Bremer J., Long-term trends in the ionospheric F2 region with two different solar activity indices, Annales Geophysicae, 2013, Vol. 31, pp. 291–303.