Variations in Ionospheric Peak Electron Density During Sudden Stratospheric Warmings in the Arctic Region

Abstract

The focus of the paper is the ionospheric disturbances during sudden stratospheric warming (SSW) events in the Arctic region. This study examines the ionospheric behavior during 12 SSW events, which occurred in the Northern Hemisphere over 2006–2013, based on vertical sounding data from DPS‐4 ionosonde located in Norilsk (88.0°E, 69.2°N). Most of the addressed events show that despite generally quiet geomagnetic conditions, notable changes in the ionospheric behavior are observed during SSWs. During the SSW evolution and peak phases, there is a daytime decrease in NmF2 values at 10–20% relative to background level. After the SSW maxima, in contrast, midday NmF2 surpasses the average monthly values for 10–20 days. These changes in the electron density are observed for both strong and weak stratospheric warmings occurring at midwinter. The revealed SSW effects in the polar ionosphere are assumed to be associated with changes in the thermospheric neutral composition, affecting the F2‐layer electron density. Analysis of the Global Ultraviolet Imager data revealed the positive variations in the O/N2 ratio within the thermosphere during SSW peak and recovery periods. Probable mechanisms for SSW impact on the state of the high‐latitude neutral thermosphere and ionosphere are discussed.

Longitudinal and Interhemispheric Ionospheric Response to 2009 and 2013 SSW Events in the African‐European and Indian‐East Asian Sectors

“…The variation in [O + /N2] ratio in the lower thermosphere changed the O + recombination rate, resulting in fluctuations in the ionospheric parameters. Yasyukevich (2018) showed an increase in the daytime GUVI [O/N2] along 88°E during the peak and decaying period of major warmings. Furthermore, Pedatella et al (2016), using numerical experiments and model simulations, revealed that enhancement in the migrating semidiurnal solar tide (SW2) during SSW modifies the lower thermosphere zonal mean circulation causing variations in [O/N2] ratio that induces a reduction in the Zonal and diurnal mean peak F layer electron density.…”

Multivariate Analysis on the Ionospheric Responses to Planetary Waves During the 2019 Antarctic SSW Event

“…It is generally accepted that the ionospheric variabilities during SSW period in the equatorial and low‐middle latitude regions are due to the modulation of vertical drift by PW and tide interactions as well as the direct impact of tidal waves (Goncharenko et al., 2010; Liu et al., 2011; Pedatella & Liu, 2013). As for the middle and high latitudinal regions, the neutral background wind changes, which are caused by the tides and SSW‐driven circulation, are significant sources for the ionospheric variations during SSW events (Pedatella et al., 2016; Yasyukevich, 2018; Yue et al., 2010).…”

The Influence of the Atmosphere on the Variability of the Electronic Concentration in the Ionosphere on January 2009

“…The n(O)/n(N 2 ) ratio was calculated according to the results of calculations of the EAGLE model based on the calculation method used in the interpretation of the GUVI data [32]. The general properties n(O)/n(N 2 ) according to the results of the calculations and observation data are as follows: negative disturbances n(O)/n(N 2 ) during warming (21-25 January), which, according to [33], is the main cause of the observed negative disturbances foF2 at midlatitudes [34,35]; and positive disturbances n(O)/n(N 2 ) at midlatitudes after warming (27-31 January), which were noted earlier [36]. Thus, the EAGLE model successfully reproduces multiday trends (quasi-period ~20 days) of disturbances in the electron content and composition of the neutral atmosphere during and after the sudden stratospheric warming of 2009.…”