Solar Cycle 24 Observations of Storm‐Enhanced Density and the Tongue of Ionization

Coster, A. J.; Erickson, Philip J.; Foster, J. C.; Thomas, E. G.; Ruohoniemi, J. M.; Baker, J. B.

doi:10.1002/9781118929216.ch6

Cited by 7 publications

(17 citation statements)

References 33 publications

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“…In Figures 4i and 4j, the rTEC enhancement with a narrow structure appears in the high‐latitude region (>60°N GMLAT) at 11:00–12:00 (MLT), which is separated from the latitudinally broad rTEC enhancement. This structure corresponds to the SED plume defined by Coster et al (2017). The enhanced rTEC region expands to the polar cap, which corresponds to the TOI.…”

Section: Characteristics Of Temporal and Spatial Variations Of The Iomentioning

confidence: 83%

“…In Figure 4h, the region with the rTEC value of more than 0.5 (corresponding to the yellow color) is observed at least in wide GMLAT and MLT ranges of 20–70°N (GMLAT) and 09:00–21:00 (MLT), respectively, although the ground GNSS‐TEC observation is not covered enough in the Russian and Ocean regions. This rTEC enhancement with a wide latitudinal and longitudinal extent corresponds to the midlatitude broad SED (Coster et al, 2017). As shown in Figure 4g, the high‐latitude convection is weakened and shrunk in association with the northward turning of the IMF, but the extension of the enhanced rTEC region is not ceased.…”

Section: Characteristics Of Temporal and Spatial Variations Of The Iomentioning

confidence: 94%

“…Based on the development of Global Positioning System (GPS) techniques and worldwide expansion of dense regional GPS receiver networks, the global change in the ionospheric electron density distribution during geomagnetic storms has been investigated using the world map of the GPS total electron content (TEC) in combination with ionospheric radars, ionosondes, optical imagers, and magnetometers (e.g., Balan et al, 2009, 2010; Coster et al, 2003, 2017; David et al, 2011; Foster et al, 2005; Heelis, 2017; Liu, Wang, Burns, Yue, et al, 2016, Liu, Wang, Burns, Solomon, et al, 2016; Maruyama, 2006; Maruyama et al, 2004, 2013; Sori et al, 2019; Thomas et al, 2013; Tsurutani et al, 2004; Yizengaw et al, 2006; Zhao et al, 2005; Zou et al, 2013). Based on the GPS‐TEC, geomagnetic field, ionosonde, and satellite observations, Tsurutani et al (2004) showed that a large TEC enhancement occurs in low‐ and middle‐latitude regions in association with the penetration of an intense convection electric field to the equatorial region during the main phase of the geomagnetic storm that occurred on 5–6 November 2001.…”

Section: Introductionmentioning

confidence: 99%

“…Moldwin et al (2016) reviewed the recent observation results and possible generation mechanisms of plasmaspheric plume, SED plume, and equatorial plasma plume. Heelis (2017) and Coster et al (2017) classified an SED phenomenon into the midlatitude broad SED with the large spatial feature and the SED plume that expands from a high‐latitude portion of the broad SED toward higher latitudes near local noon.…”

Section: Introductionmentioning

confidence: 99%

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Temporal and Spatial Variations of Total Electron Content Enhancements During a Geomagnetic Storm on 27 and 28 September 2017

et al. 2020

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Temporal and spatial evolutions of total electron content (TEC) and electron density in the ionosphere during a geomagnetic storm that occurred on 27 and 28 September 2017 have been investigated using global TEC data obtained from many Global Navigation Satellite System stations together with the ionosonde, geomagnetic field, Jicamarca incoherent scatter and Super Dual Auroral Radar Network (SuperDARN) radar data. Our analysis results show that a clear enhancement of the ratio of the TEC difference (rTEC) first occurs from noon to afternoon at high latitudes within 1 hr after a sudden increase and expansion of the high‐latitude convection and prompt penetration of the electric field to the equator associated with the southward excursion of the interplanetary magnetic field. Approximately 1–2 hr after the onset of the hmF2 increase in the midlatitude and low‐latitude regions associated with the high‐latitude convection enhancement, the rTEC and foF2 values begin to increase and the enhanced rTEC region expands to low latitudes within 1–2 hr. This signature suggests that the ionospheric plasmas in the F2 region move at a higher altitude due to local electric field drift, where the recombination rate is smaller, and that the electron density increases due to additional production at the lower altitude in the sunlit region. Later, another rTEC enhancement related to the equatorial ionization anomaly appears in the equatorial region approximately 1 hr after the prompt penetration of the electric field to the equator and expands to higher latitudes within 3–4 hr.

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Section: Characteristics Of Temporal and Spatial Variations Of The Iomentioning

confidence: 83%

Section: Characteristics Of Temporal and Spatial Variations Of The Iomentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Temporal and Spatial Variations of Total Electron Content Enhancements During a Geomagnetic Storm on 27 and 28 September 2017

et al. 2020

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“…A new multi‐instrumental era, with a large number of ground‐based instruments installed, along with multiple satellite missions operating, allowed to observe new interesting features of the dayside ionospheric behavior. For instance, intense geomagnetic storms and superstorms often generate storm‐enhanced density (SED) perturbations at high latitudes [e.g., Horvath and Lovell , ; Coster et al , ], which, in turn, can reach midlatitude regions. The amplitude of such SED can sometimes exceed that of the EIA [e.g., Lei et al , ], and to form, therefore a large third and even fourth ionization peaks poleward from the EIA.…”

Section: Introductionmentioning

confidence: 99%

Occurrence of the dayside three‐peak density structure in the F₂ and the topside ionosphere

2016

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In this work, we discuss the occurrence of the dayside three‐peak electron density structure in the ionosphere. We first use a set of ground‐based and satellite‐borne instruments to demonstrate the development of a large‐amplitude electron density perturbation at the recovery phase of a moderate storm of 11 October 2008. The perturbation developed in the F2 and low topside ionospheric regions over the American sector; it was concentrated on the north from the equatorial ionization anomaly (EIA) but was clearly separated from it. At the F2 region height, the amplitude of the observed perturbation was comparable or even exceeded that of the EIA. Further analysis of the observational data together with the Coupled Thermosphere Ionosphere Plasmasphere Electrodynamics model simulation results showed that a particular local combination of the thermospheric wind surges provided favorable conditions for the generation of the three‐peak EIA structure. We further proceed with a statistical study of occurrence of the three‐peak density structure in the ionosphere in general. Based on the analysis of 7 years of the in situ data from CHAMP satellite, we found that such three‐peak density structure occurs sufficiently often during geomagnetically quiet time. The third ionization peak develops in the afternoon hours in the summer hemisphere at solstice periods. Based on analysis of several quiet time events, we conclude that during geomagnetically quiet time, the prevailing summer‐to‐winter thermospheric circulation acts in similar manner as the storm‐time enhanced thermospheric winds, playing the decisive role in generation of the third ionization peak in the daytime ionosphere.

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Relationship Between the Locations of the Midlatitude Trough and Plasmapause Using GNSS‐TEC and Arase Satellite Observation Data

et al. 2021

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The midlatitude trough is characterized by a significant plasma depletion in the F-region of the ionosphere at subauroral and midlatitudes below the auroral oval. The structure of the midlatitude trough shows a Abstract Relationship between the locations of the midlatitude trough minimum in the ionosphere and plasmapause in the inner magnetosphere has been statistically investigated using global navigation satellite system (GNSS)-total electron content (TEC) and electron density data obtained from the Arase satellite from March 23, 2017 to May 31, 2020. In this analysis, we identify the midlatitude trough minimum as a minimum value of GNSS-TEC at subauroral and midlatitude regions, and determine the plasmapause as an electron density decrease by a factor of 5 or more within ΔL < 0.5 in the inner magnetosphere. As a result, the plasmapause does not always coincide with the midlatitude trough minimum in all magnetic local time (MLT) sectors under all geomagnetic conditions. During the geomagnetically quiet periods, the midlatitude trough minimum is located at higher and lower geomagnetic latitudes (GMLATs) of the plasmapause in the MLT ranges of 5-21 and 21-5 h, respectively. This implies that both the features could not be on the same magnetic field line. On the other hand, during the storm main phase, the midlatitude trough minimum and plasmapause move toward a low-latitude region with day-night and dawn-dusk asymmetries and the correlation becomes highest, compared with that under other geomagnetic conditions. Especially, both the features mapped on the ionosphere at a height of 300 km exist near GMLAT in the afternoon-midnight sectors. This suggests that the midlatitude trough and plasmapause are formed at almost the same location due to an enhanced subauroral polarization stream during the storm main phase.Plain Language Summary The Earth's plasmasphere, which is filled with dense cold plasmas originating from the ionosphere, has a donut-like structure in the inner magnetosphere. The plasma density decreases gradually with an increasing distance from the topside ionosphere, and it decreases sharply around the plasmapause. The location of the plasmapause tends to move toward the Earth when the geomagnetic activity increases due to the arrival of solar wind disturbances to the magnetosphere. Furthermore, the plasmaspheric plasmas give major influence on plasma wave propagation, generation, absorption, and wave-particle interaction. Therefore, to investigate the shape of the plasmasphere and the spatial distribution of plasma density is important for understanding the generation processes of high-energetic particles in the inner magnetosphere. On the other hand, it has been thought that the midlatitude trough indicating the plasma density depletion in the ionosphere with a narrow latitudinal structure corresponds to the location of the plasmapause. In this study, we investigate the relationship between the locations of the midlatitude trough minimum in the ionosphere and plasmapause in the inner magnetosphere usi...

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Solar Cycle 24 Observations of Storm‐Enhanced Density and the Tongue of Ionization

Cited by 7 publications

References 33 publications

Temporal and Spatial Variations of Total Electron Content Enhancements During a Geomagnetic Storm on 27 and 28 September 2017

Temporal and Spatial Variations of Total Electron Content Enhancements During a Geomagnetic Storm on 27 and 28 September 2017

Occurrence of the dayside three‐peak density structure in the F₂ and the topside ionosphere

Relationship Between the Locations of the Midlatitude Trough and Plasmapause Using GNSS‐TEC and Arase Satellite Observation Data

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Solar Cycle 24 Observations of Storm‐Enhanced Density and the Tongue of Ionization

Cited by 7 publications

References 33 publications

Temporal and Spatial Variations of Total Electron Content Enhancements During a Geomagnetic Storm on 27 and 28 September 2017

Temporal and Spatial Variations of Total Electron Content Enhancements During a Geomagnetic Storm on 27 and 28 September 2017

Occurrence of the dayside three‐peak density structure in the F2 and the topside ionosphere

Relationship Between the Locations of the Midlatitude Trough and Plasmapause Using GNSS‐TEC and Arase Satellite Observation Data

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Occurrence of the dayside three‐peak density structure in the F₂ and the topside ionosphere