scholarly journals The ion population of the magnetotail during the 17 April 2002 magnetic storm: Large-scale kinetic simulations and IMAGE/HENA observations

2011 ◽  
Vol 116 (A5) ◽  
Author(s):  
Vahé Peroomian ◽  
Mostafa El-Alaoui ◽  
Pontus Cson Brandt
Keyword(s):  
Magnetic Storm ◽  
Large Scale

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 Electron radiation belt dynamics during magnetic storms and in quiet time

2018 ◽  
Vol 4 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Леонид Лазутин ◽  
Leonid Lazutin ◽  
Алексей Дмитриев ◽  
Aleksey Dmitriev ◽  
Алла Суворова ◽  
...  
Keyword(s):  
Electric Field ◽  
Magnetic Storm ◽  
Large Scale ◽  
Radiation Belt ◽  
Electron Flux ◽  
Continuous Series ◽  
Outer Electron ◽  
Quiet Time ◽  
Trapping Region ◽  
Individual Character

The paper discusses the dynamics of the outer electron belt, adiabatic and nonadiabatic mechanisms of replenishment and losses of energetic electrons. Under undisturbed conditions, the outer electron belt gradually empties: in the inner magnetosphere due to electron precipitation in the atmosphere and in the quasi-trapping region due to losses at the magnetopause because drift shells of electrons are not closed there. The latter process does not occur in normal years due to the masking replenishment by freshly accelerated particles, but in years of extremely low activity it leads to a significant decrease in the electron population of the belt. During the magnetic storm main phase, the first reason for the decrease in the electron flux intensity is the adiabatic cooling associated with conservation of adiabatic invariants and complemented by precipitation of electrons into the atmosphere and their dropout at the magnetopause. Electron flux increases involve EB electron injection by the induction electric field of substorm activation and by the large-scale solar wind electric field, with pitch energy diffusion along with adiabatic heating in the recovery phase. The rate of electron flux recovery after a storm is determined by the ratio of nonadiabatic increases and losses; hence the electron flux represents a continuous series from low to very high values. The combination of these processes determines the individual character of radiation belt development during each magnetic storm and the behavior of the belt in the quiet time.

scholarly journals Parameters of large-scale TEC disturbances during the strong magnetic storm on 29 October 2003

2008 ◽  
Vol 113 (A3) ◽  
pp. n/a-n/a ◽  
Author(s):  
N. P. Perevalova ◽  
E. L. Afraimovich ◽  
S. V. Voeykov ◽  
I. V. Zhivetiev
Keyword(s):  
Magnetic Storm ◽  
Large Scale ◽  
Strong Magnetic Storm

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 Electron radiation belt dynamics during magnetic storms and in quiet time

2018 ◽  
Vol 4 (1) ◽  
pp. 59-71
Author(s):  
Леонид Лазутин ◽  
Leonid Lazutin ◽  
Алексей Дмитриев ◽  
Aleksey Dmitriev ◽  
Алла Суворова ◽  
...  
Keyword(s):  
Electric Field ◽  
Magnetic Storm ◽  
Large Scale ◽  
Radiation Belt ◽  
Electron Flux ◽  
Continuous Series ◽  
Outer Electron ◽  
Quiet Time ◽  
Trapping Region ◽  
Individual Character

The paper discusses the dynamics of the outer electron belt, adiabatic and nonadiabatic mechanisms of replenishment and losses of energetic electrons. Under undisturbed conditions, the outer electron belt gradually empties: in the inner magnetosphere due to electron precipitation in the atmosphere and in the quasi-trapping region due to losses at the magnetopause because drift shells of electrons are not closed there. The latter process does not occur in normal years due to the masking replenishment by freshly accelerated particles, but in years of extremely low activity it leads to a significant decrease in the electron population of the belt. During the magnetic storm main phase, the first reason for the decrease in the electron flux intensity is the adiabatic cooling associated with conservation of adiabatic invariants and complemented by precipitation of electrons into the atmosphere and their dropout at the magnetopause. Electron flux increases involve EB electron injection by the induction electric field of substorm activation and by the large-scale solar wind electric field, with pitch energy diffusion along with adiabatic heating in the recovery phase. The rate of electron flux recovery after a storm is determined by the ratio of nonadiabatic increases and losses; hence the electron flux represents a continuous series from low to very high values. The combination of these processes determines the individual character of radiation belt development during each magnetic storm and the behavior of the belt in the quiet time.

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 Magnetic storm effect on the occurrence of ionospheric irregularities at an equatorial station in the African sector

2014 ◽  
Vol 56 (5) ◽  
Author(s):  
Olushola Abel Oladipo ◽  
Torben Schüler
Keyword(s):  
Magnetic Storm ◽  
Local Time ◽  
Large Scale ◽  
Solar Maximum ◽  
Equatorial Region ◽  
Ionospheric Irregularities ◽  
Main Phase ◽  
Font Size ◽  
Equatorial Station ◽  
Storm Effect

<p class="MsoNormal" style="margin: 0cm 0cm 10pt;"><span style="color: black; line-height: 115%; font-family: 'Times New Roman','serif'; font-size: 12pt; mso-ansi-language: EN-US;" lang="EN-US">Large-scale ionospheric irregularities usually measured by GPS TEC fluctuation indices are regular occurrence at the equatorial region shortly after sunset around solar maximum. Magnetic storm can trigger or inhibit the generation of these irregularities depending on the local time the main phase of a particular storm occurs. We studied the effect of nine (9) distinct storms on the occurrence of ionospheric irregularities at Fraceville in Gabon (Lat = −1.63˚, Long = 13.55˚, dip lat. = −15.94˚), an equatorial station in the African sector. These storms occurred between November 2001 and September 2002. We used TEC fluctuation indices (i.e. ROTI and ROTIAVE) estimated from 30 s interval Rinex data and also we used the storm indices (i.e. Dst, dDst/dt, and IMF BZ) to predict the likely effect of each storm on the irregularities occurrence at this station. The results obtained showed that most of the storms studied inhibited ionospheric irregularities. Only one out of all the storms studied (i.e. September 4, 2002 storms with the main phase on the night of September 7-8) triggered post-midnight ionospheric irregularities. There are two of the storms during which ionospheric irregularities were observed. However, these may not be solely attributed to the storms event because the level of irregularities observed during these two storms is comparable to that observed during previous days before the storms. For this station and for the storms investigated, it seems like a little modification to the use of Aarons categories in terms of the local time the maximum negative Dst occurs could lead to a better prediction. However, it would require investigating many storms during different level of solar activities and at different latitudes to generalize this modification. <br /></span></p>

Sign in / Sign up

Export Citation Format

Share Document