Disturbances in the Magnetosphere and Ionosphere during Spotless Sun

Ionosphere Heterogeneities at Dawn−Dusk Terminator Related to the Starlink Satellites Launch Disaster on 3−8 February 2022

“…The solar terminator (ST 0 ) at sea‐level ( h = 0 km) is indicated with white‐point line, and ST h at an altitude of h = 300 km with a white‐cross line. The nighttime area surrounded with ST h (hatched area) is reduced as compared to ST 0 (Gulyaev & Gulyaeva, 1984). The intersection of Dip with ST h at GIM‐TEC (left panel) shows greater TEC SS at sunset equal to (a) 28.9 TECU and (c) 51.6 TECU at the dip between the two hills of the Equatorial Ionization Anomaly (EIA) than the sunrise TEC SR equal to (a) 7.3 TECU and (c) 5.7 TECU.…”

“…As noted by Galushko et al (1998), among all gravity waves sources, the solar terminator holds a special significance, since it is a well-defined and predictable phenomenon. The solar terminator effects in the atmosphere and ionosphere have been explored earlier by different authors (Afraimovich, 2008;Afraimovich et al, 2009;Brady & Crombie, 1964;Colonna & Tramutoli, 2021;Forbes et al, 2008;Gulyaev & Gulyaeva, 1984;Mersha et al, 2021;Miyoshi et al, 2009;Somsikov, 1995). Gravity waves with periods from a few hours down to 5 min must have impact on the charged particles variability at solar terminator similar to the neutral atmosphere density and temperature, Total Electron Content (TEC) scintillation S4 index, sporadic E layer, etc.…”

Impact of seasonal variations on low and mid-latitudes ionospheric electric field satellite measurements

“…The activities of the Sun and the Earth's position relative to the Sun are key parameters that influence various changes observed in the Earth's ionosphere, characterizing seasonal variations. Among these processes, ionospheric atoms and molecules are ionized by solar radiation and impact the densities of elements, leading to the observation of special events such as the winter/seasonal anomaly, widely noted [1], the sign reversal of seasonal variations correlations in summer [2] and the seasonal dependence of the ionospheric disturbances [3]. Earlier observation suggested that seasonal variations, such as the decrease in production of ionization at winter latitudes, are maximized at the location of extreme solar-geomagnetic season [4].…”