Dependence of long-term trends in foF2 at middle latitudes on different solar activity proxies

0580262 - ÚFA 2025 RIV NL eng J - Journal Article
Laštovička, Jan
Dependence of long-term trends in foF2 at middle latitudes on different solar activity proxies.
Advances in Space Research. Roč. 73, č. 1 (2024), s. 685-689. ISSN 0273-1177. E-ISSN 1879-1948
R&D Projects: GA ČR(CZ) GA21-03295S
Grant - others:AV ČR(CZ) StrategieAV21/30
Program: StrategieAV
Institutional support: RVO:68378289
Keywords : Ionosphere * Long-term trends * Solar activity proxies
OECD category: Meteorology and atmospheric sciences
Impact factor: 2.6, year: 2022
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0273117723007834

The most studied ionospheric parameter for long-term trends is foF2. The dominant factor of foF2 variability is the solar cycle, which is much stronger than the long-term trends. Therefore its effect in data must be removed. However, several decade long homogeneous measurements of the solar EUV fluxes are not available, so various solar activity proxies (solar activity indices) must be used. The aim of this paper is to study the impact of selection of different solar activity proxies on foF2 long-term trends and to find the best solar activity proxy for foF2 trends at middle latitudes. The results based on yearly average data of six midlatitude stations from four continents (1976–2014) and of six solar activity proxies show that the long-term trends in foF2 depend substantially on the solar activity proxy used, and the only solar proxy, which provides trends of the same sign for all stations and both sub-periods, is F30. Based on results of this paper and that of Laštovička and Burešová (2023), I can recommend F30 as the best solar proxy for studying long-term trends of foF2 at middle latitudes (at least for yearly average values).
Permanent Link: https://hdl.handle.net/11104/0349103