scholarly journals Multi-Scale Ionospheric Anomalies Monitoring and Spatio-Temporal Analysis during Intense Storm

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 215
Author(s):  
Na Cheng ◽  
Shuli Song ◽  
Wei Li
Keyword(s):  
Magnetic Storm ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Ionospheric Disturbance ◽  
Ionospheric Scintillation ◽  
Small Scale ◽  
Electron Content ◽  
Total Electron ◽  
Multi Scale ◽  
Intense Storm

The ionosphere is a significant component of the geospace environment. Storm-induced ionospheric anomalies severely affect the performance of Global Navigation Satellite System (GNSS) Positioning, Navigation, and Timing (PNT) and human space activities, e.g., the Earth observation, deep space exploration, and space weather monitoring and prediction. In this study, we present and discuss the multi-scale ionospheric anomalies monitoring over China using the GNSS observations from the Crustal Movement Observation Network of China (CMONOC) during the 2015 St. Patrick’s Day storm. Total Electron Content (TEC), Ionospheric Electron Density (IED), and the ionospheric disturbance index are used to monitor the storm-induced ionospheric anomalies. This study finally reveals the occurrence of the large-scale ionospheric storms and small-scale ionospheric scintillation during the storm. The results show that this magnetic storm was accompanied by a positive phase and a negative phase ionospheric storm. At the beginning of the main phase of the magnetic storm, both TEC and IED were significantly enhanced. There was long-duration depletion in the topside ionospheric TEC during the recovery phase of the storm. This study also reveals the response and variations in regional ionosphere scintillation. The Rate of the TEC Index (ROTI) was exploited to investigate the ionospheric scintillation and compared with the temporal dynamics of vertical TEC. The analysis of the ROTI proved these storm-induced TEC depletions, which suppressed the occurrence of the ionospheric scintillation. To improve the spatial resolution for ionospheric anomalies monitoring, the regional Three-Dimensional (3D) ionospheric model is reconstructed by the Computerized Ionospheric Tomography (CIT) technique. The spatial-temporal dynamics of ionospheric anomalies during the severe geomagnetic storm was reflected in detail. The IED varied with latitude and altitude dramatically; the maximum IED decreased, and the area where IEDs were maximum moved southward.

scholarly journals Ionospheric response to magnetar flare: signature of SGR J1550–5418 on coherent ionospheric Doppler radar

2017 ◽  
Vol 35 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Ayman Mahrous
Keyword(s):  
Total Electron Content ◽  
Large Scale ◽  
Doppler Radar ◽  
Ionospheric Disturbance ◽  
Eastern Mediterranean ◽  
Small Scale ◽  
Electron Content ◽  
Total Electron ◽  
Ionospheric Perturbations ◽  
Onset Phase

Abstract. This paper presents observational evidence of frequent ionospheric perturbations caused by the magnetar flare of the source SGR J1550–5418, which took place on 22 January 2009. These ionospheric perturbations are observed in the relative change of the total electron content (ΔTEC/Δt) measurements from the coherent ionospheric Doppler radar (CIDR). The CIDR system makes high-precision measurements of the total electron content (TEC) change along ray-paths from ground receivers to low Earth-orbiting (LEO) beacon spacecraft. These measurements can be integrated along the orbital track of the beacon satellite to construct the relative spatial, not temporal, TEC profiles that are useful for determining the large-scale plasma distribution. The observed spatial TEC changes reveal many interesting features of the magnetar signatures in the ionosphere. The onset phase of the magnetar flare was during the CIDR's nighttime satellite passage. The nighttime small-scale perturbations detected by CIDR, with ΔTEC/Δt  ≥  0.05 TECU s−1, over the eastern Mediterranean on 22 January 2009 were synchronized with the onset phase of the magnetar flare and consistent with the emission of hundreds of bursts detected from the source. The maximum daytime large-scale perturbation measured by CIDR over northern Africa and the eastern Mediterranean was detected after ∼ 6 h from the main phase of the magnetar flare, with ΔTEC/Δt  ≤  0.10 TECU s−1. These ionospheric perturbations resembled an unusual poleward traveling ionospheric disturbance (TID) caused by the extraterrestrial source. The TID's estimated virtual velocity is 385.8 m s−1, with ΔTEC/Δt  ≤  0.10 TECU s−1.

scholarly journals Combinatorial observation ionospheric characteristics during tropical cyclone Debbie passing eastern Australia in 2017 using GPS and ion sounder

2019 ◽  
Author(s):  
Fuyang Ke ◽  
Jinling Wang ◽  
Kehe Wang ◽  
Jiujing Xu ◽  
Yong Wang ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
High Frequency ◽  
Ionospheric Disturbance ◽  
Morphological Characteristics ◽  
Ionospheric Scintillation ◽  
Electron Content ◽  
Coupling Mechanism ◽  
Total Electron ◽  
Gps Satellites ◽  
Eastern Australia

Abstract. The ionospheric morphology responses to tropical cyclone passing over eastern Australia, named as DEBBIE in 2017, is investigated using Global Positioning System (GPS) Slant Total Electron Content (STEC), GPS ionospheric scintillation S4 index and ionospheric characteristics by High Frequency (HF) radio. Based on the data analysis in this study, some significant morphological characteristics of ionospheric responses to tropical cyclone Debbie are identified as follows: a) As the GPS satellites PRN01 and PRN11 were passing above typhoon center, their ROTI (Rate of STEC index) is obviously increased. b) The S4 intensity of the GPS ionospheric scintillation is significantly enhanced on March 27, which mostly concentrate around tropical cyclone center and distribute over the region within 18 °S-25 °S. c) The stronger enhancement of f0F1 and f0F2 was observed by High Frequency at Townsville on March 28, when the distance between Townsville and the center of tropical cyclone Debbie was shorter. Regarding the coupling mechanism between the ionospheric disturbance and the tropical cyclone, it is suspected that the electric field perturbations due to turbulent top movement from tropical cyclones might generate ionospheric irregularity and disturbance. To a certain extent, some ionospheric irregularities can further produce bubbles.

The global behavior of the March 1989 ionospheric storm

1992 ◽  
Vol 70 (7) ◽  
pp. 532-543 ◽  
Author(s):  
K. C. Yeh ◽  
K. H. Lin ◽  
R. O. Conkright
Keyword(s):  
Magnetic Storm ◽  
Hemispheric Asymmetry ◽  
Large Scale ◽  
Abnormal Behavior ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Equatorial Anomaly ◽  
Total Electron ◽  
Diurnal Maximum ◽  
Global Data

By any measure the magnetic storm beginning with a sudden storm commencement at 0128 UT March 13, 1989 must be classified historically as a great storm. Associated with this great magnetic storm was the drastic modification of the normal ionosphere lasting for several days. To study this abnormal behavior, ionospheric data collected at 52 ionosonde stations and 12 total electron content observing stations have been analyzed. The global data show a longitudinal dependence on the storm behavior; a pronounced worldwide depression in the diurnal maximum values of f0F2; the extreme depression of the diurnal-minimum in f0F2 to a frequency less than 2 MHz at many stations, sometimes accompanied by an unprecedented rise in h'F to 700 km or more; the presence of traveling ionospheric disturbances; the presence of large-scale standing oscillations; the development of hemispheric asymmetry; and the suppression of the equatorial anomaly. These and other unusual phenomena are described in this paper.

scholarly journals Assessment of Morelian Meteoroid Impact on Mexican Environment

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 185
Author(s):  
Maria A. Sergeeva ◽  
Vladislav V. Demyanov ◽  
Olga A. Maltseva ◽  
Artem Mokhnatkin ◽  
Mario Rodriguez-Martinez ◽  
...  
Keyword(s):  
Interesting Case ◽  
High Rate ◽  
Ionospheric Scintillation ◽  
Small Scale ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Total Electron ◽  
Total Electron Content Data ◽  
Acoustic Gravity Waves ◽  
Ionospheric Effects

Possible ionospheric effects of the Morelian meteoroid that passed and exploded over Mexico on 19 February 2020 (18 February 2020 local time) were estimated. The meteoroid trajectory, velocity and time of occurrence were calculated based on outdoor camera records. Modeling was used to estimate the meteoroid initial diameter, density, mass, velocity, energy and their change during its flight in the atmosphere. The ensemble of ionospheric scintillation indices calculated from the high-rate GNSS data and the filtered slant Total Electron Content data were used to reveal the presence of ionospheric disturbances generated by shock waves excited by the meteoroid flight and explosion. The first ionospheric responses to phenomena accompanying the meteoroid were detected (2.5–3.5) min after the explosion. The disturbances were attenuated quickly with distance from their source and were rarely recorded by GNSS receivers located more than 600 km from the meteoroid explosion site. The ionospheric disturbances of intermediate-scale, small-scale, shock-acoustic-wave-scale and sometimes medium-scale were revealed. The detected disturbances corresponded to the range of acoustic-gravity waves. An asymmetry of the disturbance manifestation in different directions was observed. The obtained results are in accordance with results of the observation of other meteoroids. Although the object was smaller and of less energy than other known meteoroids, it is an interesting case because, to the best of our knowledge, it isthe first known to us low-latitude meteoroid with the detected ionospheric effects.

scholarly journals Global propagation features of large-scale traveling ionospheric disturbances during the magnetic storm of 7~10 November 2004

2012 ◽  
Vol 30 (4) ◽  
pp. 683-694 ◽  
Author(s):  
Q. Song ◽  
F. Ding ◽  
W. Wan ◽  
B. Ning ◽  
L. Liu
Keyword(s):  
North America ◽  
Phase Velocity ◽  
East Asia ◽  
Magnetic Storm ◽  
Large Scale ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances ◽  
Damping Rate

Abstract. Larger-scale traveling ionospheric disturbances (LSTIDs) were studied using the total electron content (TEC) data observed from global GPS network in the regions of North America, Europe, and East Asia during the magnetic storm of 7~10 November 2004. 4 LSTID events were detected in North America, 4 in Europe, and 3 in East Asia. The parameters of the 11 LSTID events, such as the propagation azimuth (the angle with respect to north, taking clockwise as positive), horizontal phase velocity and damping rate were determined. Our results showed two new propagation features of the LSTIDs. One was the latitudinal dependence of the LSTIDs' propagation azimuths. The LSTIDs tended to deflect more to west from south as they propagated to lower latitudes, which indicated that the Coriolis force was one of the main causes of the LSTIDs' southwestward deviation. The other was the different mean horizontal phase velocities of LSTIDs among different regions. The mean horizontal phase velocity of LSTIDs was 422 ± 36 m s−1 in North America, 381 ± 69 m s−1 in Europe, and 527 ± 21 m s−1 in East Asia, respectively. The results also indicated that the amplitudes of LSTIDs decreased during their propagation for every event, and the daytime damping rates were more than 1 time larger than the nighttime ones due to different ion drag between daytime and nighttime. The source regions of the LSTIDs were likely to be located between geomagnetic latitudes of 68° N and 62° N in North America, and between 65° N and 57° N in Europe, according to the variation of magnetic H component observed in these two regions.

scholarly journals The nighttime ionospheric response and occurrence of equatorial plasma irregularities during geomagnetic storms: a case study

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Xin Wan ◽  
Chao Xiong ◽  
Shunzu Gao ◽  
Fuqing Huang ◽  
Yiwen Liu ◽  
...  
Keyword(s):  
Large Scale ◽  
Geomagnetic Storms ◽  
Recovery Phase ◽  
Small Scale ◽  
Electron Content ◽  
Total Electron ◽  
Ionospheric Response ◽  
Plasma Irregularities ◽  
Night Side ◽  
Ionospheric Plasma Density

AbstractRecent studies revealed that the long-lasting daytime ionospheric enhancements of Total Electron Content (TEC) were sometimes observed in the Asian sector during the recovery phase of geomagnetic storms (e.g., Lei (J Geophys Res Space Phys 123: 3217–3232, 2018), Li (J Geophys Res Space Phys 125: e2020JA028238, 2020). However, they focused only on the dayside ionosphere, and no dedicated studies have been performed to investigate the nighttime ionospheric behavior during such kinds of storm recovery phases. In this study, we focused on two geomagnetic storms that happened on 7–8 September 2017 and 25–26 August 2018, which showed the prominent daytime TEC enhancements in the Asian sector during their recovery phases, to explore the nighttime large-scale ionospheric responses as well as the small-scale Equatorial Plasma Irregularities (EPIs). It is found that during the September 2017 storm recovery phase, the nighttime ionosphere in the American sector is largely depressed, which is similar to the daytime ionospheric response in the same longitude sector; while in the Asian sector, only a small TEC increase is observed at nighttime, which is much weaker than the prominent daytime TEC enhancement in this longitude sector. During the recovery phase of the August 2018 storm, a slight TEC increase is observed on the night side at all longitudes, which is also weaker than the prominent daytime TEC enhancement. For the small-scale EPIs, they are enhanced and extended to higher latitudes during the main phase of both storms. However, during the recovery phases of the first storm, the EPIs are largely enhanced and suppressed in the Asian and American sectors, respectively, while no prominent nighttime EPIs are observed during the second storm recovery phase. The clear north–south asymmetry of equatorial ionization anomaly crests during the second storm should be responsible for the suppression of EPIs during this storm. In addition, our results also suggest that the dusk side ionospheric response could be affected by the daytime ionospheric plasma density/TEC variations during the recovery phase of geomagnetic storms, which further modulates the vertical plasma drift and plasma gradient. As a result, the growth rate of post-sunset EPIs will be enhanced or inhibited.

Traveling Ionospheric Disturbances Characteristics during the 2018 Typhoon Maria from GPS Observations

2020 ◽  
Vol 12 (4) ◽  
pp. 746 ◽  
Author(s):  
Yiduo Wen ◽  
Shuanggen Jin
Keyword(s):  
Time Series ◽  
Large Scale ◽  
Ionospheric Disturbance ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Dual Frequency ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances ◽  
Gps Observations

Typhoons often occur and may cause huge loss of life and damage of infrastructures, but they are still difficult to precisely monitor and predict by traditional in-situ measurements. Nowadays, ionospheric disturbances at a large-scale following typhoons can be monitored using ground-based dual-frequency Global Positioning System (GPS) observations. In this paper the responses of ionospheric total electron content (TEC) to Typhoon Maria on 10 July 2018 are studied by using about 150 stations of the GPS network in Taiwan. The results show that two significant ionospheric disturbances on the southwest side of the typhoon eye were found between 10:00 and 12:00 UTC. This was the stage of severe typhoon and the ionospheric disturbances propagated at speeds of 118.09 and 186.17 m/s, respectively. Both traveling ionospheric disturbances reached up to 0.2 TECU and the amplitudes were slightly different. The change in the filtered TEC time series during the typhoon was further analyzed with the azimuth. It can be seen that the TEC disturbance anomalies were primarily concentrated in a range of between −0.2 and 0.2 TECU and mainly located at 135–300° in the azimuth, namely the southwest side of the typhoon eye. The corresponding frequency spectrum of the two TEC time series was about 1.6 mHz, which is consistent with the frequency of gravity waves. Therefore, the upward propagating gravity wave was the main cause of the traveling ionospheric disturbance during Typhoon Maria.

scholarly journals Ionosphere dynamics over the Southern Hemisphere during the 31 March 2001 severe magnetic storm using multi-instrument measurement data

2005 ◽  
Vol 23 (3) ◽  
pp. 707-721 ◽  
Author(s):  
E. Yizengaw ◽  
P. L. Dyson ◽  
E. A. Essex ◽  
M. B. Moldwin
Keyword(s):  
Magnetic Storm ◽  
Southern Hemisphere ◽  
Large Scale ◽  
Tomographic Reconstruction ◽  
Measurement Data ◽  
Equatorial Region ◽  
Electron Content ◽  
Clear Understanding ◽  
Inversion Algorithm ◽  
Total Electron

Abstract. The effects of the 31 March 2001 severe magnetic storm on the Southern Hemisphere ionosphere have been studied using ground-based and satellite measurements. The prime goal of this comprehensive study is to track the ionospheric response from high-to-low latitude to obtain a clear understanding of storm-time ionospheric change. The study uses a combination of ionospheric Total Electron Content (TEC) obtained from GPS signal group delay and phase advance measurements, ionosonde data, and data from satellite in-situ measurements, such as the Defense Metrological Satellite Program (DMSP), TOPographic EXplorer (TOPEX), and solar wind data from the Advanced Composition Explorer (ACE). A chain of Global Positioning System (GPS) stations near the 150° E meridian has been used to give comprehensive latitude coverage extending from the cusp to the equatorial region. A tomographic inversion algorithm has been applied to the GPS TEC measurements to obtain maps of the latitudinal structure of the ionospheric during this severe magnetic storm period, enabling both the spatial and temporal response of the ionosphere to be studied. Analysis of data from several of the instruments indicates that a strong density enhancement occurred at mid-latitudes at 11:00 UT on 31 March 2001 and was followed by equatorward propagating large-scale Travelling Ionospheric Disturbances (TIDs). The tomographic reconstruction revealed important features in ionospheric structure, such as quasi-wave formations extending finger-like to higher altitudes. The most pronounced ionospheric effects of the storm occurred at high- and mid-latitudes, where strong positive disturbances occurred during the storm main phase, followed by a long lasting negative storm effect during the recovery phase. Relatively minor storm effects occurred in the equatorial region.

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