Semi‐Monthly Lunar Tide Oscillation of f oF2 in Equatorial Ionization Anomaly (EIA) Crests During 2014–2015 SSW

2021 ◽  
Vol 126 (2) ◽  
Author(s):  
Qiong Tang ◽  
Chen Zhou ◽  
Zi‐Shen Li ◽  
Yi Liu ◽  
Guan‐Yi Chen
Keyword(s):  
Lunar Tide ◽  
Equatorial Ionization Anomaly

On the solar modulation of the atmospheric lunar tide

Tellus ◽  
1980 ◽  
Vol 32 (1) ◽  
pp. 27-32
Author(s):  
A. Palumbo ◽  
A. Mazzarella
Keyword(s):  
Solar Modulation ◽  
Lunar Tide

scholarly journals High-speed stream impacts on the equatorial ionization anomaly region during the deep solar minimum year 2008

2012 ◽  
Vol 117 (A10) ◽  
pp. n/a-n/a ◽  
Author(s):  
Jing Liu ◽  
Libo Liu ◽  
Biqiang Zhao ◽  
Yong Wei ◽  
Lianhuan Hu ◽  
...  
Keyword(s):  
Solar Minimum ◽  
High Speed ◽  
High Speed Stream ◽  
Equatorial Ionization Anomaly ◽  
Anomaly Region

scholarly journals Super plasma fountain and equatorial ionization anomaly during penetration electric field

2009 ◽  
Vol 114 (A3) ◽  
pp. n/a-n/a ◽  
Author(s):  
N. Balan ◽  
K. Shiokawa ◽  
Y. Otsuka ◽  
S. Watanabe ◽  
G. J. Bailey
Keyword(s):  
Electric Field ◽  
Equatorial Ionization Anomaly

scholarly journals Seasonal, Diurnal, and Solar-Cycle Variations of Electron Density at Two West Africa Equatorial Ionization Anomaly Stations

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Frédéric Ouattara ◽  
Doua Allain Gnabahou ◽  
Christine Amory Mazaudier
Keyword(s):  
Solar Cycle ◽  
West Africa ◽  
Ultraviolet Radiation ◽  
Correlation Coefficient ◽  
Sunspot Number ◽  
Extreme Ultraviolet ◽  
Cycle Phase ◽  
Significant Variability ◽  
Equatorial Ionization Anomaly ◽  
Significant Difference

We analyse the variability of foF2 at two West Africa equatorial ionization anomaly stations (Ouagadougou and Dakar) during three solar cycles (from cycle 20 to cycle 22), that is, from 1966 to 1998 for Ouagadougou and from 1971 to 1997 for Dakar. We examine the effect of the changing levels of solar extreme ultraviolet radiation with sunspot number. The study shows high correlation between foF2 and sunspot number (Rz). The correlation coefficient decreases from cycle 20 to cycle 21 at both stations. From cycle 21 to cycle 22 it decreases at Ouagadougou station and increases at Dakar station. The best correlation coefficient, 0.990, is obtained for Dakar station during solar cycle 22. The seasonal variation displays equinoctial peaks that are asymmetric between March and September. The percentage deviations of monthly average data from one solar cycle to another display variability with respect to solar cycle phase and show solar ultraviolet radiation variability with solar cycle phase. The diurnal variation shows a noon bite out with a predominant late-afternoon peak except during the maximum phase of the solar cycle. The diurnal Ouagadougou station foF2 data do not show a significant difference between the increasing and decreasing cycle phases, while Dakar station data do show it, particularly for cycle 21. The percentage deviations of diurnal variations from solar-minimum conditions show more ionosphere during solar cycle 21 at both stations for all three of the other phases of the solar cycle. There is no significant variability of ionosphere during increasing and decreasing solar cycle phases at Ouagadougou station, but at Dakar station there is a significant variability of ionosphere during these two solar-cycle phases.

scholarly journals An investigation of the ionospheric F region near the EIA crest in India using OI 777.4 and 630.0 nm nightglow observations

2018 ◽  
Vol 36 (3) ◽  
pp. 809-823 ◽  
Author(s):  
Navin Parihar ◽  
Sandro Maria Radicella ◽  
Bruno Nava ◽  
Yenca Olivia Migoya-Orue ◽  
Prabhakar Tiwari ◽  
...  
Keyword(s):  
Electron Density ◽  
Gravity Waves ◽  
Satellite Mission ◽  
Low Latitude ◽  
Density Maximum ◽  
Density Profiles ◽  
F Region ◽  
Equatorial Ionization Anomaly ◽  
Low Latitude Ionosphere ◽  
Electron Density Profiles

Abstract. Simultaneous observations of OI 777.4 and OI 630.0 nm nightglow emissions were carried at a low-latitude station, Allahabad (25.5° N, 81.9° E; geomag. lat.  ∼  16.30° N), located near the crest of the Appleton anomaly in India during September–December 2009. This report attempts to study the F region of ionosphere using airglow-derived parameters. Using an empirical approach put forward by Makela et al. (2001), firstly, we propose a novel technique to calibrate OI 777.4 and 630.0 nm emission intensities using Constellation Observing System for Meteorology, Ionosphere, and Climate/Formosa Satellite Mission 3 (COSMIC/FORMOSAT-3) electron density profiles. Next, the electron density maximum (Nm) and its height (hmF2) of the F layer have been derived from the information of two calibrated intensities. Nocturnal variation of Nm showed the signatures of the retreat of the equatorial ionization anomaly (EIA) and the midnight temperature maximum (MTM) phenomenon that are usually observed in the equatorial and low-latitude ionosphere. Signatures of gravity waves with time periods in the range of 0.7–3.0 h were also seen in Nm and hmF2 variations. Sample Nm and hmF2 maps have also been generated to show the usefulness of this technique in studying ionospheric processes.

scholarly journals foF2 Long-Term Trend at a Station Located near the Crest of the Equatorial Ionization Anomaly

2020 ◽  
Vol 11 (08) ◽  
pp. 518-528
Author(s):  
Doua Allain Gnabahou ◽  
Sibri Alphonse Sandwidi ◽  
Frédéric Ouattara
Keyword(s):  
Term Trend ◽  
Equatorial Ionization Anomaly ◽  
Long Term Trend

scholarly journals On the variability of the semidiurnal solar and lunar tides of the equatorial electrojet during sudden stratospheric warmings

2018 ◽  
Author(s):  
Tarique A. Siddiqui ◽  
Astrid Maute ◽  
Nick Pedatella ◽  
Yosuke Yamazaki ◽  
Hermann Lühr ◽  
...  
Keyword(s):  
Zonal Wind ◽  
Equatorial Electrojet ◽  
Stratospheric Warming ◽  
Tidal Amplitude ◽  
Lunar Tide ◽  
Sudden Stratospheric Warming ◽  
Lunar Tides ◽  
Neutral Temperature ◽  
Tidal Changes ◽  
Solar Tide

Abstract. The variabilities of the semidiurnal solar and lunar tide of the equatorial electrojet (EEJ) are investigated during the 2003, 2006, 2009 and 2013 major sudden stratospheric warming (SSW) events in this study. For this purpose, the ground-magnetometer recordings at the equatorial observatories in Huancayo and Fuquene are utilized. Results show a major enhancement in the amplitude of the EEJ semidiurnal lunar tide in each of the four warming events. The EEJ semidiurnal solar tidal amplitude shows an amplification prior to the onset of warmings, a reduction during the deceleration of the zonal mean zonal wind at 60° N and 10 hPa and a second enhancement a few days after the peak reversal of the zonal mean zonal wind during all the four SSWs. Results also reveal that the amplitude of the EEJ semidiurnal lunar tide becomes comparable or even greater than the amplitude of the EEJ semidiurnal solar tide during all these warming events. The present study also compares the EEJ semidiurnal solar and lunar tidal changes with numerical simulations of the variability of the migrating semidiurnal solar (SW2) and lunar (M2) tide in neutral temperature at ~ 120 km altitude. A better agreement between the enhancements of the EEJ semidiurnal lunar tide and the M2 tide in neutral temperature is observed in comparison with the enhancements of the EEJ semidiurnal solar tide and the SW2 tide in neutral temperature.

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