Variations in Thermosphere Composition and Ionosphere Total Electron Content Under “Geomagnetically Quiet” Conditions at Solar‐Minimum

Cai, Xuguang; Burns, A. G.; Wang, Wenbin; Qian, Liying; Pedatella, Nicholas; Coster, A. J.; Zhang, Shun‐Rong; Solomon, Stanley C.; Eastes, R.; Daniell, R. E.; McClintock, W. E.

doi:10.1029/2021gl093300

Cited by 47 publications

(67 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The K p index (Figure 1b) exhibited periods of moderate activity, with K p values exceeding four on several occasions. Though this does not represent significant geomagnetic activity, even minor to moderate variations in K p can impact the ionosphere [43]. The F10.7 cm solar flux had a high of ∼110 sfu on day −32, and then steadily declined to ∼70 sfu around day 5, where it remained relatively constant for the remainder of the time period.…”

Section: Resultsmentioning

confidence: 92%

Ionospheric Variability during the 2020–2021 SSW: COSMIC-2 Observations and WACCM-X Simulations

Pedatella

2022

Atmosphere

Self Cite

View full text Add to dashboard Cite

Variability in the ionosphere during the 2020–2021 sudden stratospheric warming (SSW) is investigated using a combination of Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2) observations and the Whole Atmosphere Community Climate Model with thermosphere–ionosphere eXtension (WACCM-X) simulations. The unprecedented spatial–temporal sampling of the low latitude ionosphere afforded by COSMIC-2 enables investigating the short-term (<5 days) variability in the ionosphere during the SSW event. The COSMIC-2 observations reveal a reduction in the diurnal and zonal mean ionosphere total electron content (ITEC) and reduced amplitude of the diurnal variation in the ionosphere during the SSW. Enhanced ITEC amplitudes of the semidiurnal solar and lunar migrating tides and the westward propagating semidiurnal tide with zonal wavenumber 3 are also observed. The WACCM-X simulations demonstrate that these variations are driven by variability in the stratosphere–mesosphere during the 2020–2021 SSW event. The results show the impact of the 2020–2021 SSW on the mean state, diurnal, and semidiurnal variations in the ionosphere, as well as the capabilities of the COSMIC-2 mission to observe short-term variability in the ionosphere that is driven by meteorological variability in the lower atmosphere.

show abstract

Section: Resultsmentioning

confidence: 92%

Ionospheric Variability during the 2020–2021 SSW: COSMIC-2 Observations and WACCM-X Simulations

Pedatella

2022

Atmosphere

Self Cite

View full text Add to dashboard Cite

show abstract

“…Additionally, Cai, Burns, Wang, Qian, Pedatella, et al (2021) found two cases for which ∑O/N 2 and ionospheric total electron content (TEC) exhibited long (5-11 hr) and strong (∼maximum of 30% the reference values) day-to-day variations at mid-latitudes in the daytime during periods that have been usually considered as geomagnetically quiet times (maximum Kp = 1.7). These studies further showed the potentially important roles of geomagnetic disturbance during "quiet period" in generating observed day-to-day thermosphere composition and ionosphere plasma variations in the mid-latitudes (see Figures 1 and 2 in Cai, Burns, Wang, Qian, Pedatella, et al, 2021). These studies raise two interesting questions: how does the high-latitude energy and momentum deposition from the magnetosphere cause changes in thermospheric composition at high latitudes and then at mid-latitudes during some "geomagnetically quiet" periods at solar-minimum?…”

mentioning

confidence: 99%

The Effects of IMF B_y on the Middle Thermosphere During a Geomagnetically “Quiet” Period at Solar Minimum

et al. 2022

Self Cite

View full text Add to dashboard Cite

Numerical simulations using the National Center for Atmospheric Research (NCAR) thermosphere‐ionosphere‐electrodynamics general circulation model (TIE‐GCM) are performed to elucidate the effects of the interplanetary magnetic field (IMF) on the middle thermosphere composition during a “geomagnetically quiet” period from the day of year (DOY) 110–111 in 2019 (when the Auroral electrojet (AE) index never exceeded 300 nT and the Kp never exceeded 2). In particular, this paper aims to examine how the Global‐scale Observations of the Limb and Disk (GOLD) mission observed daytime thermospheric O and N2 column density ratio (∑O/N2) depletion at mid‐latitudes originated under such a “geomagnetically quiet” condition. A comparison of electric potential, Joule heating rate per unit mass, ion velocity, neutral temperature and winds in the middle thermosphere (∼160 km) between real IMF and without the IMF east‐west component (By) indicates that a By dominant condition can enhance their strengths under this “geomagnetically quiet” condition. Consequently, ∑O/N2 depletion with a stronger magnitude (30% compared with ∼8% without By) and larger disturbed area was introduced in the post‐midnight sector at high‐latitudes due to strong and localized upwelling associated with the enhanced Joule heating rate per unit mass. The ∑O/N2 depletion was transported equatorward and corotated from local post‐midnight to early morning, and was observed by GOLD at middle latitudes during daytime.

show abstract

“…An increase in the geomagnetic activity during QD seems to result in the overestimation by the PCA-MRM models of the night TEC values: ∆TEC increases, MAE does not change. The dependence of TEC variations on the weak geomagnetic activity seen even during the quiet days can be related to the coupling between the high-and mid-latitudinal regions of the ionosphere, as was pointed out in [30].…”

Section: Assessment Of the Forecasting Skills During Quiet Daysmentioning

confidence: 56%

PCA-MRM Model to Forecast TEC at Middle Latitudes

2022

View full text Add to dashboard Cite

The total electron content (TEC) over the Iberian Peninsula was modelled using PCA-MRM models based on decomposition of the observed TEC series using the principal component analysis (PCA) and reconstruction of the daily modes’ amplitudes by a multiple linear regression model (MRM) using space weather parameters as regressors. The following space weather parameters are used: proxies for the solar UV and XR fluxes, number of the solar flares of different classes, parameters of the solar wind and of the interplanetary magnetic field, and geomagnetic indices. Time lags of 1 and 2 days between the TEC and space weather parameters are used. The performance of the PCA-MRM model is tested using data for 2015, both geomagnetically quiet and disturbed periods. The model performs well for quiet days and days with solar flares but without geomagnetic disturbances. The MAE and RMSE metrics are of the order of 3–5 TECu for daytime and ~2 TECu for night-time. During geomagnetically disturbed periods, the performance of the model deteriorates but only for daytime: MAE and RMSE are of the order of 4–6 TECu and can rise to ~13 TECu for the strongest geomagnetic storms.

show abstract

Variations in Thermosphere Composition and Ionosphere Total Electron Content Under “Geomagnetically Quiet” Conditions at Solar‐Minimum

Cited by 47 publications

References 33 publications

Ionospheric Variability during the 2020–2021 SSW: COSMIC-2 Observations and WACCM-X Simulations

Ionospheric Variability during the 2020–2021 SSW: COSMIC-2 Observations and WACCM-X Simulations

The Effects of IMF B_y on the Middle Thermosphere During a Geomagnetically “Quiet” Period at Solar Minimum

PCA-MRM Model to Forecast TEC at Middle Latitudes

Contact Info

Product

Resources

About

Variations in Thermosphere Composition and Ionosphere Total Electron Content Under “Geomagnetically Quiet” Conditions at Solar‐Minimum

Cited by 47 publications

References 33 publications

Ionospheric Variability during the 2020–2021 SSW: COSMIC-2 Observations and WACCM-X Simulations

Ionospheric Variability during the 2020–2021 SSW: COSMIC-2 Observations and WACCM-X Simulations

The Effects of IMF By on the Middle Thermosphere During a Geomagnetically “Quiet” Period at Solar Minimum

PCA-MRM Model to Forecast TEC at Middle Latitudes

Contact Info

Product

Resources

About

The Effects of IMF B_y on the Middle Thermosphere During a Geomagnetically “Quiet” Period at Solar Minimum