A statistical study of single crest phenomenon in the equatorial ionospheric anomaly region using Swarm A satellite

Fathy, Adel; Ghamry, Essam

doi:10.1016/j.asr.2016.12.020

Cited by 12 publications

(19 citation statements)

References 24 publications

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“…For more details concerning the density at the peak and its magnetic latitude, see Table 1. Fathy and Ghamry (2017) reported that the majority of single crests (86%) is observed between 08:00 and 12:00 magnetic local time. They reported that the lowest number of single crests (14%) is observed within the dawn side and before midnight.…”

Section: Latitudinal Distribution Average Of Ionospheric Electron Den...mentioning

confidence: 99%

Interhemispheric Asymmetry of the Equatorial Ionization Anomaly (EIA) on the African Sector Over 3 Years (2014–2016): Effects of Thermospheric Meridional Winds

et al. 2022

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One of the important phenomena of the equatorial and midlatitude ionosphere is the equatorial ionization anomaly (EIA). It forms as a consequence of the equatorial fountain effect (Appleton, 1946;Martyn, 1947;MITRA, 1946;Schunk & Nagy, 2000), caused by the upward vertical E × B/B 2 plasma drift that elevates the F region ionosphere plasma to higher altitudes over the magnetic equator, followed by diffusion along the geomagnetic field lines, that moves the plasma down and away from the equator, forming ionization crests in both sides of the magnetic equator and an ionization trough over the dip equator. The latitudinal plasma distribution that characterizes the EIA (a trough at the magnetic equator and two crests at approximately ±17° magnetic latitude) is well reproduced by many theoretical models (

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Section: Latitudinal Distribution Average Of Ionospheric Electron Den...mentioning

confidence: 99%

Interhemispheric Asymmetry of the Equatorial Ionization Anomaly (EIA) on the African Sector Over 3 Years (2014–2016): Effects of Thermospheric Meridional Winds

et al. 2022

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“…Their findings revealed that the single crest occurs primarily on days with low solar activity. Fathy and Ghamry (2017) studied the features of single crest using Swarm-A satellite data at different seasons and local times. They found that the single crest displaces its location away from the equator to the northern hemisphere in summer and in the winter to the southern hemisphere.…”

Section: Introductionmentioning

confidence: 99%

Ionospheric single crest events at different altitudes and activity levels observed by Swarm constellation

Hussien

Ghamry

Mohammed

et al. 2023

Astrophys Space Sci

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The current work makes use of eight years of electron density data observed by the Swarm constellation to study the characteristics of the equatorial ionospheric single crest phenomenon recorded at the altitudes of these satellites. The features of single crests have been investigated at different altitudes and geomagnetic activity levels. Results showed that the occurrence rate of a single crest was not significantly different between the lower and higher satellite altitudes. The relationship between the occurrence of single crests and the Kp index has shown a dramatic enhancement at high level activities. In addition, the occurrence of single crest has dramatically enhanced with the strength of both the interplanetary electric field and the north-south interplanetary magnetic field. Also, irrespective of season, the South Atlantic Anomaly (SAA) region has always shown a large occurrence of single crest events compared to other longitudes. In addition, the occurrence of the events is always larger during equinoxes than during summer and winter solstices. The significant occurrence of single crest recorded during both equinoxes and the maximum phase of the solar cycle (F10.7 index) and those observed over the SSA region, suggests an alignment between the strength of electron density and the occurrence rate of single crests.

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“…The north−south hemispheric asymmetry of the IBIs in summer months could be attributed to the large electron density which develops steeper ∇ n according to Equation (1) [17,46]. Also, it is worth noting that the large electron density during equinoxes [55] is considered the main reason behind the large equinoctial IBIs. Also, the authors of [53] proposed that the increase in the background plasma density at the topside F region improves the EPB development in two ways: by enhancing the growth of EPD along the flux tube or by maintaining EPB rising upward.…”

Section: Discussionmentioning

confidence: 99%

“…On 22 November 2013, the Swarm mission was launched into an almost polar orbit with an inclination angle of 87.5 • at an initial altitude of about 490 km. From that time, Swarm A and C fly alongside each other at an altitude of about 470 km and with a longitudinal separation distance of about 1.4 • (150 km) [55,56]. The third spacecraft, Swarm B, swirls the Earth at about 520 km with a higher inclination.…”

Section: Swarm Satellite Missionmentioning

confidence: 99%

A Statistical Analysis of Plasma Bubbles Observed by Swarm Constellation during Different Types of Geomagnetic Storms

2021

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Based on the observations of Ionospheric Bubble Index (IBI) data from the Swarm mission, the characteristics of plasma bubbles are investigated during different types of geomagnetic storms recorded from 2014 to 2020. The geometrical constellation of the Swarm mission enabled us to investigate the altitudinal profile of the IBIs during different activity levels in a statistical mean. Results show that the majority of IBIs associated with moderate storms are observed at low altitudes and the probability of observing IBIs at high altitudes (Swarm-B) increases with the increase in storm level. This is confirmed by observing the F2 layer peak height (hmF2) during super storm events at larger altitudes using COSMIC data. The maximum number of IBIs is recorded within the South Atlantic Anomaly (SAA) region with a long duration time and tends to increase only during dusk time. Both the large duration time and number of IBIs over the South Atlantic Anomaly (SAA) suggest that the gradient in the electron density and the depression in the magnetic field are the main factors controlling IBI events. Also, the IBIs at high altitudes are larger at sunset and at low altitudes pre-midnight. In addition, the occurrence of IBIs is always larger in the northern hemisphere than in the southern hemisphere irrespective of the type of storm, as well as during the summer months. Moreover, there is no correlation between the duration time of IBIs and both the altitudinal observation of the IBIs and the storm type. Seasonal occurrence of IBIs is larger during equinoxes and vice versa during solstices irrespective of both the type of storm and the altitude of the satellite. The large number of IBIs during equinoxes agrees with the previous studies, which expect that the large electron density is a developer of steeper . Large occurrences of super storm IBIs observed within the pre-midnight during summer and at sunset during equinoxes are a novel observation that needs further investigation. Also, the majority of IBIs are observed a few hours after geomagnetic substorms, which reflects the role of the Disturbance Dynamo Electric Field (DDEF) as a main driver of IBIs.

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A statistical study of single crest phenomenon in the equatorial ionospheric anomaly region using Swarm A satellite

Cited by 12 publications

References 24 publications

Interhemispheric Asymmetry of the Equatorial Ionization Anomaly (EIA) on the African Sector Over 3 Years (2014–2016): Effects of Thermospheric Meridional Winds

Interhemispheric Asymmetry of the Equatorial Ionization Anomaly (EIA) on the African Sector Over 3 Years (2014–2016): Effects of Thermospheric Meridional Winds

Ionospheric single crest events at different altitudes and activity levels observed by Swarm constellation

A Statistical Analysis of Plasma Bubbles Observed by Swarm Constellation during Different Types of Geomagnetic Storms

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