Ionospheric Long-Term Trends and Its Relevance to Space Weather

ANA G. ELIAS; ZOSSI, BRUNO S.; FAGRE, MARIANO; SAAVEDRA, ZENON; MEDINA, FRANCO D.; MARIA GRACIELA MOLINA

Workshop; Space Weather Workshop 2021; 2021

The Earth's ionosphere presents long-term trends that have been of interest since a pioneering study in 1989 suggesting that long-term increase of greenhouse gases concentration would produce a global cooling in the upper atmosphere in addition to the global warming in the troposphere. Since then, investigation of long-term changes in the upper atmosphere and ionosphere has become a significant topic in global change research. Even though anthropogenic forcing seems to be the main trend driver, there are other ionospheric long-term change forcings. Among them is the secular variation of Earth's magnetic field, which affects not only the electron density, but currents flowing in the ionosphere and magnetosphere, ionospheric conductivity, and radio wave propagation as well. The ionosphere, as a part of the space weather environment, plays a crucial role through the modulation of the global electrodynamic circuit, its coupling to the magnetosphere and as a key medium for communication, sounding and navigation. Certainly it could be said that space weather cannot be fully understood without reference to the ionosphere. Thus, a thorough understanding of its variability in all time scales becomes crucial. In this work, ionospheric trends are analyzed linked to their relevance for space weather. These trends, although weak, are steady and may become significant in the future and of importance for long-term space weather forecasts.