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 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 RESPON TEC IONOSFER DI ATAS BANDUNG DAN MANADO TERKAIT FLARE SINAR-X MATAHARI KELAS M5.1 DAN M7.9 TAHUN 2015 (IONOSPHERIC TEC RESPONSE OVER BANDUNG DAN MANADO ASSOCIATED WITH M5.1 AND M7.9 CLASSES OF SOLAR FLARE XRAYS IN 2015)

2018 ◽  
Vol 14 (2) ◽  
pp. 111
Author(s):  
Sri Ekawati
Keyword(s):  
Time Delay ◽  
Solar Flare ◽  
Electron Density ◽  
Total Electron Content ◽  
Geomagnetic Latitude ◽  
Ionospheric Scintillation ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
X Rays ◽  
Total Electron

The solar flare is potential to cause sudden increase of the electron density in the ionosphere,particularly in D layer, known as Sudden Ionospheric Disturbances (SID). This increase of electron density occurs not only in the ionospheric D layer but also in the ionospheric E and F layers. Total Electron Content (TEC) measured by GPS is the total number of electrons from D to F layer. The aim of this research is to study the effect of solar flare x-rays, greater than M5 class in 2015, on ionospheric TEC over Bandung and Manado. This paper presents the preliminary result of ionospheric TEC response on solar flare occurrence over Indonesia. The ionospheric TEC data is derived from GPS Ionospheric Scintillation and TEC Monitor (GISTM) receiver at Bandung (-6.90o S;107.6o E geomagnetic latitude 16.54o S) and Manado (1.48o N; 124.85o E geomagnetic latitude 7.7o S). The solar x-rays flares classes analyzed where M5.1 on 10 March 2015 and M7.9 on 25 June 2015. Slant TEC (STEC) values where calculated to obtain Vertical TEC (VTEC) and the Differential of the VTEC (DVTEC) per PRN satellite for further analysis. The results showed that immediately after the flare, there where sudden enhancement of the VTEC and the DVTEC (over Bandung and Manado) at the same time. The time delay of ionospheric TEC response on M5.1 flare was approximately 2 minutes, then the VTEC increased by 0.5 TECU and the DVTEC rose sharply by 0.5 – 0.6 TECU/minutes. Moreover, the time delay after the M7.9 flare was approximately 11 minutes, then the VTEC increased by 1 TECU and the DVTEC rose sharply by 0.6 – 0.9 TECU/minutes. ABSTRAK Flare matahari berpotensi meningkatkan kerapatan elektron ionosfer secara mendadak, khususnya di lapisan D, yang dikenal sebagai Sudden Ionospheric Disturbances (SID). Peningkatan kerapatan elektron tersebut terjadi tidak hanya di lapisan D, tetapi juga di lapisan E dan F ionosfer. Total Electron Content (TEC) dari GPS merupakan jumlah banyaknya elektron total dari lapisan D sampai lapisan F. Penelitian ini bertujuan mengetahui efek flare, yang lebih besar dari kelas M5 tahun 2015, terhadap TEC ionosfer di atas Bandung dan Manado. Makalah ini merupakan hasil awal dari respon TEC ionosfer terhadap fenomena flare di atas Indonesia. Data TEC ionosfer diperoleh dari penerima GPS Ionospheric Scintillation and TEC Monitor (GISTM) di Bandung (-6,90o S; 107,60o E lintang geomagnet 16,54o LS) dan Manado (1,48oLU;124,85oBT lintang geomagnet 7,7o LS) dikaitkan dengan kejadian flare kelas M5.1 pada tanggal 10 Maret 2015 dan kelas M7.9 pada tanggal 25 Juni 2015. Nilai Slant TEC (STEC) dihitung untuk memperoleh nilai Vertical TEC (VTEC), kemudian nilai Differential of VTEC (DVTEC) per PRN satelit diperoleh untuk analisis selanjutnya. Hasil menunjukkan segera setelah terjadi flare, terjadi peningkatan VTEC dan DVTEC (di atas Bandung dan Manado) secara mendadak pada waktu yang sama. Waktu tunda dari respon TEC ionosfer setelah terjadi flare M5.1 adalah sekitar 2 menit, kemudian VTEC meningkat sebesar 0,5 TECU dan DVTEC meningkat secara tajam sebesar 0,5 – 0,6 TECU/menit. Sedangkan, waktu tunda setelah terjadi flare M7.9 adalah 11 menit, kemudian VTEC meningkat sebesar 1 TECU dan DVTEC meningkat secara tajam sebesar 0,6 – 0,9 TECU/menit.

scholarly journals Isolated ionospheric disturbances as deduced from global GPS network

2004 ◽  
Vol 22 (1) ◽  
pp. 47-62 ◽  
Author(s):  
E. L. Afraimovich ◽  
E. I. Astafieva ◽  
S. V. Voyeikov
Keyword(s):  
Total Electron Content ◽  
Acoustic Waves ◽  
Mean Value ◽  
Global Network ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Total Electron ◽  
Radio Science ◽  
Acoustic Gravity Waves ◽  
Medium Scale

Abstract. We investigate an unusual class of medium-scale traveling ionospheric disturbances of the nonwave type, isolated ionospheric disturbances (IIDs) that manifest themselves in total electron content (TEC) variations in the form of single aperiodic negative TEC disturbances of a duration of about 10min (the total electron content spikes, TECS). The data were obtained using the technology of global detection of ionospheric disturbances using measurements of TEC variations from a global network of receivers of the GPS. For the first time, we present the TECS morphology for 170 days in 1998–2001. The total number of TEC series, with a duration of each series of about 2.3h (2h18m), exceeded 850000. It was found that TECS are observed in no more than 1–2% of the total number of TEC series mainly in the nighttime in the spring and autumn periods. The TECS amplitude exceeds the mean value of the "background" TEC variation amplitude by a factor of 5–10 as a minimum. TECS represent a local phenomenon with a typical radius of spatial correlation not larger than 500km. The IID-induced TEC variations are similar in their amplitude, form and duration to the TEC response to shock-acoustic waves (SAW) generated during rocket launchings and earthquakes. However, the IID propagation velocity is less than the SAW velocity (800–1000m/s) and are most likely to correspond to the velocity of background medium-scale acoustic-gravity waves, on the order of 100–200m/s. Key words. Ionosphere (ionospheric irregularities, instruments and techniques) - Radio science (ionospheric propagation)

scholarly journals Geomagnetic control of the spectrum of traveling ionospheric disturbances based on data from a global GPS network

2001 ◽  
Vol 19 (7) ◽  
pp. 723-731 ◽  
Author(s):  
E. L. Afraimovich ◽  
E. A. Kosogorov ◽  
O. S. Lesyuta ◽  
I. I. Ushakov ◽  
A. F. Yakovets
Keyword(s):  
Geomagnetic Activity ◽  
Time Derivative ◽  
Power Spectra ◽  
Small Scale ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Geomagnetic Disturbances ◽  
Absolute Level ◽  
Total Electron ◽  
Traveling Ionospheric Disturbances

Abstract. In this paper an attempt is made to verify the hypothesis of the role of geomagnetic disturbances as a factor in determining the intensity of traveling ionospheric disturbances (TIDs). To improve the statistical validity of the data, we have used the method involving a global spatial averaging of disturbance spectra of the total electron content (TEC). To characterize the TID intensity quantitatively, we suggest that a new global index of the degree of disturbance should be used, which is equal to the mean value of the rms variations in TEC within the selected range of spectral periods (of 20– 60 min, in the present case). The analysis has been made for a set of 100 to 300 GPS stations for 10 days with a different level of geomagnetic activity (Dst from 0 to –350 nT; the Kp index from 3 to 9). It was found that power spectra of daytime TEC variations in the range of 20–60 min periods under quiet conditions have a power-law form with the slope index k = –2.5. With an increase in the level of magnetic disturbance, there is an increase in the total intensity of TIDs, with a concurrent kink of the spectrum caused by an increase in oscillation intensity in the range of 20–60 min. The TEC variation amplitude is found to be smaller at night than during the daytime, and the spectrum decreases in slope, which is indicative of a disproportionate increase in the amplitude of the small-scale part of the spectrum. It was found that an increase in the level of geomagnetic activity is accompanied by an increase in the total intensity of TEC; however, it does not correlate with the absolute level of Dst, but rather with the value of the time derivative of Dst (a maximum correlation coefficient reaches –0.94). The delay of the TID response of the order of 2 hours is consistent with the view that TIDs are generated in auroral regions, and propagate equatorward with the velocity of about 300–400 m/s.Key words. Ionosphere (ionospheric disturbances; auroral ionosphere; equatorial ionopshere)

scholarly journals IONOSPHERIC DISTURBANCES OVER EASTERN SIBERIA DURING APRIL 12–15, 2016 GEOMAGNETIC STORMS

2020 ◽  
Vol 6 (1) ◽  
pp. 75-85
Author(s):  
Aleksandr Rubtsov ◽  
Boris Maletckii ◽  
Ekaterina Danilchuk ◽  
Ekaterina Smotrova ◽  
Aleksei Shelkov ◽  
...  
Keyword(s):  
Electron Density ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Peak Height ◽  
Negative Response ◽  
Small Scale ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Total Electron ◽  
Optical Instruments

We present the results of the complex study of ionospheric parameter variations during two geomagnetic storms, which occurred on April 12–15, 2016. The study is based on data from a set of radiophysical and optical instruments. Both the storms with no sudden commencement were generated by high-speed streams from a coronal hole. Despite the minor intensity of the storms (Dst ≥ –55 and –59 nT), we have revealed a distinct ionospheric response to these disturbances. A negative response of electron density and F2-layer critical frequency was observed during the main phase of both the storms. The amplitude of the negative response was higher for the second storm. The period of negative electron density deviations was accompanied by an increase in the peak height, as well as by the downward plasma drift in the evening and night hours, which is not typical of quiet conditions. We have also recorded sharp peaks in the AATR (Along Arc TEC Rate) index and in total electron content noise spikes on average 2–2.5 times. This indicates an intensification of small-scale ionospheric disturbances caused by disturbed geomagnetic conditions and high substorm activity.

scholarly journals Scintillation measurements at Bahir Dar during the high solar activity phase of solar cycle 24

2017 ◽  
Vol 35 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Martin Kriegel ◽  
Norbert Jakowski ◽  
Jens Berdermann ◽  
Hiroatsu Sato ◽  
Mogese Wassaie Mersha
Keyword(s):  
Drift Velocity ◽  
Global Navigation Satellite Systems ◽  
High Rate ◽  
High Solar Activity ◽  
Small Scale ◽  
Electron Content ◽  
Bahir Dar ◽  
Total Electron ◽  
Plasma Irregularities ◽  
Cross Correlation Analysis

Abstract. Small-scale ionospheric disturbances may cause severe radio scintillations of signals transmitted from global navigation satellite systems (GNSSs). Consequently, small-scale plasma irregularities may heavily degrade the performance of current GNSSs such as GPS, GLONASS or Galileo. This paper presents analysis results obtained primarily from two high-rate GNSS receiver stations designed and operated by the German Aerospace Center (DLR) in cooperation with Bahir Dar University (BDU) at 11.6° N, 37.4° E. Both receivers collect raw data sampled at up to 50 Hz, from which characteristic scintillation parameters such as the S4 index are deduced. This paper gives a first overview of the measurement set-up and the observed scintillation events over Bahir Dar in 2015. Both stations are located close to one another and aligned in an east–west, direction which allows us to estimate the zonal drift velocity and spatial dimension of equatorial ionospheric plasma irregularities. Therefore, the lag times of moving electron density irregularities and scintillation patterns are derived by applying cross-correlation analysis to high-rate measurements of the slant total electron content (sTEC) along radio links between a GPS satellite and both receivers and to the associated signal power, respectively. Finally, the drift velocity is derived from the estimated lag time, taking into account the geometric constellation of both receiving antennas and the observed GPS satellites.

scholarly journals ADDTID: An Alternative Tool for Studying Earthquake/Tsunami Signatures in the Ionosphere. Case of the 2011 Tohoku Earthquake

2019 ◽  
Vol 11 (16) ◽  
pp. 1894 ◽  
Author(s):  
Heng Yang ◽  
Enrique Monte Moreno ◽  
Manuel Hernández-Pajares
Keyword(s):  
Acoustic Waves ◽  
Tohoku Earthquake ◽  
Location Estimation ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Vertical Total Electron Content ◽  
The 2011 Tohoku Earthquake ◽  
Total Electron ◽  
Acoustic Gravity Waves ◽  
Traveling Ionospheric Disturbances

In this work, we characterized the ionospheric disturbances generated during the Japan Tohoku earthquake of 11 March 2011, by means of the Atomic Decomposition Detector of Traveling Ionospheric Disturbances (ADDTID) algorithm. This algorithm automatically detects and characterizes Traveling Ionospheric Disturbances (TIDs) from Global Navigation Satellite System (GNSS) measurements. Applying the high-precision estimates of ADDTID, the propagation parameters would make it easier to distinguish TIDs from different origins, in particular the characteristics conforming the acoustic gravity waves driven by the earthquake/tsunami. This method does not assume that disturbances follow a circular pattern of propagation, and can estimate the location by the propagation pattern of tsunami wavefronts and related TIDs. In this work, we present in a single framework a description of phenomena observed by different researchers. By means of the ADDTID algorithm, we detect: (a) simultaneous TIDs of different characteristics, where the detection was robust against the curvature of the wave fronts of the perturbations and the accuracy of the estimated parameters. The results were double-checked by visual inspection from detrended Vertical Total Electron Content (VTEC) maps and keogram plots, and the parameters of the slow-speed TIDs were consistent with the tsunami waveform measurements; (b) different wavefronts between the west and east TIDs around the epicenter, consistent in time and space with the post-earthquake tsunami; (c) complete evolution of the circular TIDs driven by the tsunami during the GNSS observable area; (d) fast and short circular TIDs related to the acoustic waves of earthquake; (e) the pre-seismic activity consisting of a set of fast westward TIDs, and the comparison with neighboring days; (f) the location estimation of the tsunami wavefront along the coast and the possible use as early warning. Finally, we report disturbances that had not been previously published with a possible application to local and real-time detection of tsunamis.

scholarly journals IONOSPHERIC DISTURBANCES OVER EASTERN SIBERIA DURING APRIL 12–15, 2016 GEOMAGNETIC STORMS

2020 ◽  
Vol 6 (1) ◽  
pp. 60-68
Author(s):  
Aleksandr Rubtsov ◽  
Boris Maletckii ◽  
Ekaterina Danilchuk ◽  
Ekaterina Smotrova ◽  
Aleksei Shelkov ◽  
...  
Keyword(s):  
Electron Density ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Peak Height ◽  
Negative Response ◽  
Small Scale ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Total Electron ◽  
Optical Instruments

We present the results of the complex study of ionospheric parameter variations during two geomagnetic storms, which occurred on April 12–15, 2016. The study is based on data from a set of radiophysical and optical instruments. Both the storms with no sudden commencement were generated by high-speed streams from a coronal hole. Despite the minor intensity of the storms (Dst ≥ –55 and –59 nT), we have revealed a distinct ionospheric response to these disturbances. A negative response of electron density and F2-layer critical frequency was observed during the main phase of both the storms. The amplitude of the negative response was higher for the second storm. The period of negative electron density deviations was accompanied by an increase in the peak height, as well as by the downward plasma drift in the evening and night hours, which is not typical of quiet conditions. We have also recorded sharp peaks in the AATR (Along Arc TEC Rate) index and in total electron content noise spikes on average 2–2.5 times. This indicates an intensification of small-scale ionospheric disturbances caused by disturbed geomagnetic conditions and high substorm activity.

scholarly journals New observations of the total electron content and ionospheric scintillations over Ho Chi Minh City

2020 ◽  
Vol 42 (4) ◽  
Author(s):  
Tam Dao ◽  
Minh Le Huy ◽  
Brett Carter ◽  
Que Le ◽  
Thanh Thuy Trinh ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Rate Of Change ◽  
Ho Chi Minh City ◽  
Ionospheric Scintillation ◽  
Phase Method ◽  
Small Scale ◽  
Electron Content ◽  
Total Electron ◽  
Gnss Receiver ◽  
Ionospheric Scintillations

In January 2018, a Trimble NetR9 GNSS receiver was installed at International University - Vietnam National University (IU-VNU), which is located at 10°52'N, 106°48'E in Ho Chi Minh City (HCMC). The GNSS signals recorded from the receiver are useful for studying the ionospheric variations over this station as well as the magnetosphere-ionosphere coupling effects, therefore, we aim to preliminarily process and evaluate data recorded from this new station. Based on the data obtained with this GNSS receiver, we first estimated the total electron content (TEC) using the carrier-phase method which is a combination of code and phase measurements. We then calculated the rate of change of TEC index (ROTI) with respect to time and investigated its day-to-day variations. Our results show some typical features in the diurnal and seasonal TEC and ionospheric scintillation variations during 2018-2019. The distributions of ROTI over these two years of solar minimum show significant occurrences of scintillation, which are caused by small-scale ionospheric irregularities in the equatorial ionosphere. In addition, we found a significant increase of TEC in the latest strong geomagnetic storm in August 2018. The disturbance dynamo appears to have suppressed plasma bubbles after sunset and enhanced their formation at midnight. Thus, the disturbance dynamo effectively caused a delay of ionospheric scintillations. The TEC observed in HCMC also contributes to the data of ground-based observational receiver systems along 105o E longitude for studying ionospheric variations in low-latitude and equatorial regions. Our preliminary results indicate that the GNSS data collected at IU-VNU station is a valuable reference dataset for further research of the ionosphere.

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