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 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 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 A case study of the large-scale traveling ionospheric disturbances in the East Asian sector during the 2015 St. Patrick’s Day geomagnetic storm

2019 ◽  
Author(s):  
Jing Liu ◽  
Dong-He Zhang ◽  
Anthea J. Coster ◽  
Shun-Rong Zhang ◽  
Guan-Yi Ma ◽  
...  
Keyword(s):  
Geomagnetic Storm ◽  
Large Scale ◽  
East Asian ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
East Side ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances ◽  
Propagation Parameters ◽  
Perturbation Maps

Abstract. This study gives the first observation of the large-scale traveling ionospheric disturbances (LSTIDs) in the East Asian sector during the 2015 St. Patrick’s Day (March 17, 2015) geomagnetic storm. For the first time, 3 dense networks of GPS receivers in China and Japan are combined together to obtain the 2-dimensional (2D) vertical total electron content (VTEC) perturbation maps in a wider longitudinal range than previous works in this region. Results show that a negative LSTID spanning at least 60° in longitude (80° E–140° E) occurs and propagating from high to lower latitudes around 09:40–11:20 UT. It is followed by a positive LSTID which shows a tendency of dissipation starting from the East side. The manifestation of the 2D VTEC perturbation maps is in good agreement with the recordings from 2 high-frequency Doppler shift stations and the iso-frequency lines from 8 ionosondes. Then, the propagation parameters of the LSTIDs are estimated by applying least square fitting methods to the distinct structures in the 2D VTEC perturbation plots. In general, the propagation parameters are observably longitudinal dependent. For example, the propagation direction is almost due southward between 105° E–115° E, while it is slightly South by West/East in the West/East side of this region. This feature is probably related to the regional geomagnetic declination. The mean values of the period, trough velocity (Vt), crest velocity (Vc), and wavelength of the wavelike LSTIDs in the studied longitudinal bands are 74.8 ± 1.4 minutes, 578 ± 16 m/s, 617 ± 23 m/s, and 2691 ± 80 km, respectively. Finally, using the VTEC map data from the Madrigal database of the MIT Haystack Observatory, the characteristics of the ionospheric disturbances over the European sector (30° N–70° N, 10° E–20° E) are also studied. The results are very different from those in the East Asian sector in parameters like the occurrence time, oscillation period, and propagation velocities.

scholarly journals Dynamics of disturbance level of total electron content at high and middle latitudes according to GPS data

2016 ◽  
Vol 2 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Наталья Перевалова ◽  
Natalia Perevalova ◽  
Илья Едемский ◽  
Ilya Edemsky ◽  
Ольга Тимофеева ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Large Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Continuous Series ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Minimum Level ◽  
Total Electron ◽  
The Arctic Region

We study the level of total electron content (TEC) disturbance in ionospheric mid-latitude and high-latitude regions during 2013. TEC behavior is calculated using data from two GPS stations: MOND (Mondy) and NRIL (Norilsk). TEC variations are calculated from two-frequency phase measurements for all radio rays. We analyze the TEC variations in two time ranges: 10 and 40 min. These ranges correspond to middle- and large-scale ionospheric disturbances respectively. The TEC disturbance level is characterized using the special index WTEC. WTEC allows us to receive multi-day continuous series of average TEC variation intensity. We reveal that at high latitudes WTEC variations agree well with AE ones. The correlation between WTEC and Dst variations is much less. The minimum level of TEC disturbance is independent of the season in the Arctic region; diurnal WTEC variations are more pronounced for medium-scale ionospheric disturbances than for large-scale ones. At mid-latitudes, the WTEC behavior agrees well with the Dst and Kp variations only during strong magnetic storms. The minimum level of TEC disturbance is higher in summer than in winter. At mid-latitudes, the sunset terminator generates gravitational waves. In the Arctic region, terminator-generated waves are not observed.

scholarly journals Identification of potential precursors for the occurrence of Large-Scale Traveling Ionospheric Disturbances in a case study during September 2017

2020 ◽  
Vol 10 ◽  
pp. 32
Author(s):  
Arthur Amaral Ferreira ◽  
Claudia Borries ◽  
Chao Xiong ◽  
Renato Alves Borges ◽  
Jens Mielich ◽  
...  
Keyword(s):  
Real Time ◽  
Electron Density ◽  
Large Scale ◽  
Rate Of Change ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances ◽  
Auroral Activity

Traveling Ionospheric Disturbances (TIDs) reflect changes in the ionospheric electron density which are caused by atmospheric gravity waves. These changes in the electron density impact the functionality of different applications such as precise navigation and high-frequency geolocation. The Horizon 2020 project TechTIDE establishes a warning system for the occurrence of TIDs with the motivation to mitigate their impact on communication and navigation applications. This requires the identification of appropriate indicators for the generation of TIDs and for this purpose we investigate potential precursors for the TID occurrence. This paper presents a case study of the double main phase geomagnetic storm, starting from the night of 7th September and lasting until the end of 8th September 2017. Detrended Total Electron Content (TEC) derived from Global Navigation Satellite System (GNSS) measurements from more than 880 ground stations in Europe was used to identify the occurrence of different types of large scale traveling ionospheric disturbances (LSTIDs) propagating over the European sector. In this case study, LSTIDs were observed more frequently and with higher amplitude during periods of enhanced auroral activity, as indicated by increased electrojet index (IE) from the International Monitor for Auroral Geomagnetic Effects (IMAGE). Our investigation suggests that Joule heating due to the dissipation of Pedersen currents is the main contributor to the excitation of the observed LSTIDs. We observe that the LSTIDs are excited predominantly after strong ionospheric perturbations at high-latitudes. Ionospheric parameters including TEC gradients, the Along Arc TEC Rate (AATR) index and the Rate Of change of TEC index (ROTI) have been analysed for their suitability to serve as a precursor for LSTID occurrence in mid-latitude Europe, aiming for near real-time indication and warning of LSTID activity. The results of the presented case study suggest that the AATR index and TEC gradients are promising candidates for near real-time indication and warning of the LSTIDs occurrence in mid-latitude Europe since they have a close relation to the source mechanisms of LSTIDs during periods of increased auroral activity.

scholarly journals Simultaneous observations of large-scale traveling ionospheric disturbances on the nightside and dayside middle latitude

2012 ◽  
Vol 30 (12) ◽  
pp. 1709-1717 ◽  
Author(s):  
H. T. Cai ◽  
F. Yin ◽  
S. Y. Ma ◽  
J. S. Xu ◽  
Y. W. Liu
Keyword(s):  
North American ◽  
Large Scale ◽  
Source Region ◽  
Phase Speed ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Gps Receiver ◽  
Atmospheric Gravity Wave ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances

Abstract. In this paper, we present further observational evidence for the transpolar propagation of large-scale traveling ionospheric disturbances (LSTIDs) from their nightside source region to the dayside reported by Cai et al. (2011). Slant total electron content (STEC) observed by longitudinally aligned GPS receiver chains in North American and European sectors was analyzed to demonstrate presences of LSTIDs at both nightside and dayside mid-latitude. Signatures of TID were inferred from phase difference in time series of STEC perturbations (TECP) derived from measurements of ground-based GPS receivers, which are separated by hundreds of kilometers longitudinally. Periods of the daytime and nighttime ionospheric disturbances were estimated to be around 128 min, being in good agreement with that of the transpolar AGW (atmospheric gravity wave) recorded by EISCAT (European Incoherent Scatter Scientific Association)/ESR (EISCAT Svalbard Radar) radars. On the dayside, the LSTID moved equatorward with an average phase speed of ~440 m s−1. In North American sector, however, southward speed of the nighttime LSTID was much slower, being around 160 m s−1. We suggest that the observed daytime and nighttime mid-latitude LSTIDs are likely to have the same source region, being located somewhere at nighttime auroral latitude. Having been launched on the nightside, the waves propagate simultaneously equatorward and poleward. The equatorward-moving waves are recorded by GPS receiver chain in North American sector. The poleward-moving waves, however, cross the polar cap from nightside to dayside and then are detected consecutively at high and mid-latitudes by EISCAT/ESR radars and GPS receiver chains, respectively.

scholarly journals Direct Connection Between Auroral Oval Streamers/Flow Channels and Equatorward Traveling Ionospheric Disturbances

2021 ◽  
Vol 8 ◽  
Author(s):  
Larry R. Lyons ◽  
Yukitoshi Nishimura ◽  
Shunrong Zhang ◽  
Anthea Coster ◽  
Jiang Liu ◽  
...  
Keyword(s):  
Large Scale ◽  
Auroral Oval ◽  
Electron Precipitation ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Direct Connection ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances ◽  
Flow Channels ◽  
Ground Magnetic

We use simultaneous auroral imaging, radar flows, and total electron content (TEC) measurements over Alaska to examine whether there is a direct connection of large-scale traveling ionospheric disturbances (LSTIDs) to auroral streamers and associated flow channels having significant ground magnetic decreases. Observations from seven nights with clearly observable flow channels and/or auroral streamers were selected for analysis. Auroral observations allow identification of streamers, and TEC observations detect ionization enhancements associated with streamer electron precipitation. Radar observations allow direct detection of flow channels. The TEC observations show direct connection of streamers to TIDs propagating equatorward from the equatorward boundary of the auroral oval. The TIDs are also distinguished from the streamers to which they connect by their wave-like TEC fluctuations moving more slowly equatorward than the TEC enhancements from streamer electron precipitation. TIDs previously observed propagating equatorward from the auroral oval have been identified as LSTIDs. Thus, the TIDs here are likely LSTIDs, but we lack sufficient TEC coverage necessary to demonstrate that they are indeed large scale. Furthermore, each of our events shows TID’s connection to groups of a few streamers and flow channels over a period in the order of 15 min and a longitude range of ∼15–20°, and not to single streamers. (Groups of streamers are common during substorms. However, it is not currently known if streamers and associated flow channels typically occur in such groups.) We also find evidence that a flow channel must lead to a sufficiently large ionospheric current for it to lead to a detectable LSTID, with a few tens of nT ground magnetic field decreases not being sufficient.

scholarly journals The Southern Hemisphere and equatorial region ionization response for a 22 September 1999 severe magnetic storm

2004 ◽  
Vol 22 (8) ◽  
pp. 2765-2773 ◽  
Author(s):  
E. Yizengaw ◽  
E. A. Essex ◽  
R. Birsa
Keyword(s):  
Magnetic Storm ◽  
Temporal Variations ◽  
Equatorial Region ◽  
Dominant Negative ◽  
Time Shift ◽  
Electron Content ◽  
Eastern Region ◽  
Equatorial Anomaly ◽  
Total Electron ◽  
Positioning Systems

Abstract. The ionospheric storm evolution process was monitored during the 22 September 1999 magnetic storm over the Australian eastern region, through measurements of the ionospheric Total Electron Content (TEC) from seven Global Positioning Systems (GPS) stations. The spatial and temporal variations of the ionosphere were analysed as a time series of TEC maps. Results of our analysis show that the main ionospheric effect of the storm under consideration are: the long lasting negative storm effect during a magnetic storm at mid-latitude regions; the strong, positive disturbances during the storm's main phase at auroral latitude regions; the effects of storm-induced equatorward directed wind causing a positive disturbance at high and mid-latitude stations with appropriate time shift between higher and lower latitudes; daytime poleward movement of depleted plasma that causes temporary suppression of the equatorial anomaly during the start of the storm recovery phase; and prompt penetration of eastward electric fields to ionospheric altitudes and the production of nearly simultaneous TEC enhancement at all latitudes. In general, we found dominant negative disturbance over mid and high latitudes and positive disturbance at low latitudes. A comparison of storm-time behaviour of TEC determined from GPS satellites, and foF2 derived from ionosondes at a range of latitudes, showed reasonable agreement between the two independent measurements.

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