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Journal articles on the topic 'Travelling ionospheric disturbances'

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Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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1

Madonia, Paolo, Alessandro Bonaccorso, Alessandro Bonforte, Ciro Buonocunto, Andrea Cannata, Luigi Carleo, Claudio Cesaroni, et al. "Propagation of Perturbations in the Lower and Upper Atmosphere over the Central Mediterranean, Driven by the 15 January 2022 Hunga Tonga-Hunga Ha’apai Volcano Explosion." Atmosphere 14, no. 1 (December 29, 2022): 65. http://dx.doi.org/10.3390/atmos14010065.

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The Hunga Tonga-Hunga Ha’apai volcano (Pacific Ocean) generated a cataclysmic explosion on 15 January 2022, triggering several atmospheric disturbances at a global scale, as a huge increase in the total electron content (TEC) in the ionosphere, and a pressure wave travelling in the troposphere. We collected and analysed data over the Mediterranean to study these disturbances, and in particular, (i) data from the barometric and infrasonic stations installed on Italian active volcanoes by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) for investigating the tropospheric pressure waves; (ii) barometric data from the INGV-TROPOMAG and SIAS (Sicilian Agro-meteorological Information System) networks, for investigating the interaction between the orography and pressure waves; (iii) ionograms from the Advanced Ionospheric Sounder-INGV ionosonde at Gibilmanna (Sicily, Italy); (iv) data from the RING (Rete Italiana Integrata GNSS) network, to retrieve the ionospheric TEC; (v) soil CO2 flux data from the INGV surveillance network of Vulcano Island. The analysis of the ground-level barometric data highlights that pressure waves were reflected and diffracted by the topographic surface, creating a complex space–time dynamic of the atmospheric disturbances travelling over Sicily, driven by the interference among the different wavefronts. The ionograms show that a medium-scale travelling ionospheric disturbance (MSTID), with a horizontal wavelength of about 220 km and a period of about 35 min, propagated through the ionospheric plasma in the correspondence of the first barometric variations. Moreover, comparing detrended TEC and barometric data, we further confirmed the presence of the aforementioned MSTID together with its close relation to the tropospheric disturbance.

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2

Liu, Tong, Zhibin Yu, Zonghua Ding, Wenfeng Nie, and Guochang Xu. "Observation of Ionospheric Gravity Waves Introduced by Thunderstorms in Low Latitudes China by GNSS." Remote Sensing 13, no. 20 (October 15, 2021): 4131. http://dx.doi.org/10.3390/rs13204131.

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The disturbances of the ionosphere caused by thunderstorms or lightning events in the troposphere have an impact on global navigation satellite system (GNSS) signals. Gravity waves (GWs) triggered by thunderstorms are one of the main factors that drive short-period Travelling Ionospheric Disturbances (TIDs). At mid-latitudes, ionospheric GWs can be detected by GNSS signals. However, at low latitudes, the multi-variability of the ionosphere leads to difficulties in identifying GWs induced by thunderstorms through GNSS data. Though disturbances of the ionosphere during low-latitude thunderstorms have been investigated, the explicit GW observation by GNSS and its propagation pattern are still unclear. In this paper, GWs with periods from 6 to 20 min are extracted from band-pass filtered GNSS carrier phase observations without cycle-slips, and 0.2–0.8 Total Electron Content Unit (TECU) magnitude perturbations are observed when the trajectories of ionospheric pierce points fall into the perturbed region. The propagation speed of 102.6–141.3 m/s and the direction of the propagation indicate that the GWs are propagating upward from a certain thunderstorm at lower atmosphere. The composite results of disturbance magnitude, period, and propagation velocity indicate that GWs initiated by thunderstorms and propagated from the troposphere to the ionosphere are observed by GNSS for the first time in the low-latitude region.

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3

Afraimovich, E. L., K. S. Palamartchouk, and N. P. Perevalova. "GPS radio interferometry of travelling ionospheric disturbances." Journal of Atmospheric and Solar-Terrestrial Physics 60, no. 12 (January 1998): 1205–23. http://dx.doi.org/10.1016/s1364-6826(98)00074-1.

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4

Blanc, Elisabeth, and Brigitte Mercandalli-Rascalou. "Mid-latitude ionospheric disturbances produced by major magnetic storms." Canadian Journal of Physics 70, no. 7 (July 1, 1992): 553–65. http://dx.doi.org/10.1139/p92-090.

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Large-scale ionospheric disturbances were observed in France by HF ionospheric sounding measurements during major magnetic storms, specially during the March 13–14, 1989 storm. The experiment used a network of four stations (one continuous wave transmitting station and three receiving stations) to determine the horizontal component of the phase velocity of the travelling disturbances by triangulation. The vertical component was determined by using several frequencies on one of the links and ionograms indicated overall ionospheric changes every 30 min. During the first diurnal phase of the March 13, 1989 magnetic storm, four large oscillations of the F2-layer critical frequency f0F2 were observed. During the first and second f0F2 decreases, a dense F1 region, revealing strong compositional changes in the lower thermosphere, modulated the oscillations and contributed to a F2-region virtual height increase to above 800 km. The Doppler measurements at 150–180 km detected only magnetic pulsations and southward travelling acoustic waves. The large-scale disturbances reached the altitude of the Doppler measurements 30 min after the fourth f0F2 peak, with a rapid upward and downward plasma drift of 250 m s−1. This disturbance moved to the southwest at 860 m s−1. During the March 13–14 nocturnal phase an auroral type Es appeared, formed by irregularities extending over 800 km. The ionosphere almost disappeared at 0330 UT and a low-density spread F was observed until the sunrise; the Doppler links were interrupted all the night. During the March 14 morning phase, southward travelling acoustic waves were observed and the F region seemed to be limited to the F1 region. This is probably an effect of the extreme G condition, arising from a decrease of the F2-layer maximum below the F1-layer maximum. The principal features of this storm are compared with those of two other storms on April 12, 1990 and August 14–15, 1989.

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5

MacDougall, J. W., D. A. Andre, G. J. Sofko, C. S. Huang, and A. V. Koustov. "Travelling ionospheric disturbance properties deduced from Super Dual Auroral Radar measurements." Annales Geophysicae 18, no. 12 (December 31, 2000): 1550–59. http://dx.doi.org/10.1007/s00585-001-1550-z.

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Abstract. Based on modeling of the perturbations in power and elevation angle produced by travelling ionospheric disturbances (TIDs), and observed by the Super Dual Auroral Radar Network, procedures for determining the TID properties are suggested. These procedures are shown to produce reasonable agreement with those properties of the TIDs that can be measured from simultaneous ionosonde measurements. The modeling shows that measurements of angle-of-elevation perturbations by SuperDARN allows for better determination of the TID properties than using only the perturbations of power as is commonly done.Key words: Ionosphere (auroral ionosphere; ionosphere-atmosphere interactions)

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6

He, L. S., P. L. Dyson, M. L. Parkinson, and W. Wan. "Studies of medium scale travelling ionospheric disturbances using TIGER SuperDARN radar sea echo observations." Annales Geophysicae 22, no. 12 (December 22, 2004): 4077–88. http://dx.doi.org/10.5194/angeo-22-4077-2004.

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Abstract. Seasonal and diurnal variations in the direction of propagation of medium-scale travelling ionospheric disturbances (MSTIDs) have been investigated by analyzing sea echo returns detected by the TIGER SuperDARN radar located in Tasmania (43.4° S, 147.2° E geographic; –54.6°Λ). A strong dependency on local time was found, as well as significant seasonal variations. Generally, the propagation direction has a northward (i.e. equatorward) component. In the early morning hours the direction of propagation is quite variable throughout the year. It then becomes predominantly northwest and changes to northeast around 09:00 LT. In late fall and winter it changes back to north/northwest around 15:00 LT. During the other seasons, northward propagation is very obvious near dawn and dusk, but no significant northward propagation is observed at noon. It is suggested that the variable propagation direction in the morning is related to irregular magnetic disturbances that occur at this local time. The changes in the MSTID propagation directions near dawn and dusk are generally consistent with changes in ionospheric electric fields occurring at these times and is consistent with dayside MSTIDs being generated by the Lorentz force. Key words. Ionosphere (ionospheric disturbances; wave propagation; ionospheric irregularities; signal processing)

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7

Hocke, K., and K. Schlegel. "A review of atmospheric gravity waves and travelling ionospheric disturbances: 1982-1995." Annales Geophysicae 14, no. 9 (September 30, 1996): 917–40. http://dx.doi.org/10.1007/s00585-996-0917-6.

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Abstract. Recent investigations of atmospheric gravity waves (AGW) and travelling ionospheric disturbances (TID) in the Earth\\'s thermosphere and ionosphere are reviewed. In the past decade, the generation of gravity waves at high latitudes and their subsequent propagation to low latitudes have been studied by several global model simulations and coordinated observation campaigns such as the Worldwide Atmospheric Gravity-wave Study (WAGS), the results are presented in the first part of the review. The second part describes the progress towards understanding the AGW/TID characteristics. It points to the AGW/TID relationship which has been recently revealed with the aid of model-data comparisons and by the application of new inversion techniques. We describe the morphology and climatology of gravity waves and their ionospheric manifestations, TIDs, from numerous new observations.

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8

Stocker, A. J., N. F. Arnold, and T. B. Jones. "The synthesis of travelling ionospheric disturbance (TID) signatures in HF radar observations using ray tracing." Annales Geophysicae 18, no. 1 (January 31, 2000): 56–64. http://dx.doi.org/10.1007/s00585-000-0056-4.

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Abstract. Characteristic signatures are often observed in HF radar range-time-intensity plots when travelling ionospheric disturbances (TIDs) are present. These signatures, in particular the variation of the F-region skip distance, have been synthesised using a ray tracing model. The magnitude of the skip variation is found to be a function of the peak electron density perturbation associated with the TID and radar frequency. Examination of experimental observations leads to an estimate of the peak electron density perturbation amplitude of around 25% for those TIDs observed by the CUTLASS radar system. The advantage of using the skip variation over the radar return amplitude as an indicator of density perturbation is also discussed. An example of a dual radar frequency experiment has been given. The investigation of the effect of radar frequency on the observations will aid the optimisation of future experiments..Key words. Ionosphere (auroral ionosphere; ionosphere -atmosphere interactions; ionospheric disturbances)

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9

Namgaladze, A. A., M. Förster, and R. Y. Yurik. "Analysis of the positive ionospheric response to a moderate geomagnetic storm using a global numerical model." Annales Geophysicae 18, no. 4 (April 30, 2000): 461–77. http://dx.doi.org/10.1007/s00585-000-0461-8.

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Abstract. Current theories of F-layer storms are discussed using numerical simulations with the Upper Atmosphere Model, a global self-consistent, time dependent numerical model of the thermosphere-ionosphere-plasmasphere-magnetosphere system including electrodynamical coupling effects. A case study of a moderate geomagnetic storm at low solar activity during the northern winter solstice exemplifies the complex storm phenomena. The study focuses on positive ionospheric storm effects in relation to thermospheric disturbances in general and thermospheric composition changes in particular. It investigates the dynamical effects of both neutral meridional winds and electric fields caused by the disturbance dynamo effect. The penetration of short-time electric fields of magnetospheric origin during storm intensification phases is shown for the first time in this model study. Comparisons of the calculated thermospheric composition changes with satellite observations of AE-C and ESRO-4 during storm time show a good agreement. The empirical MSISE90 model, however, is less consistent with the simulations. It does not show the equatorward propagation of the disturbances and predicts that they have a gentler latitudinal gradient. Both theoretical and experimental data reveal that although the ratio of [O]/[N2] at high latitudes decreases significantly during the magnetic storm compared with the quiet time level, at mid to low latitudes it does not increase (at fixed altitudes) above the quiet reference level. Meanwhile, the ionospheric storm is positive there. We conclude that the positive phase of the ionospheric storm is mainly due to uplifting of ionospheric F2-region plasma at mid latitudes and its equatorward movement at low latitudes along geomagnetic field lines caused by large-scale neutral wind circulation and the passage of travelling atmospheric disturbances (TADs). The calculated zonal electric field disturbances also help to create the positive ionospheric disturbances both at middle and low latitudes. Minor contributions arise from the general density enhancement of all constituents during geomagnetic storms, which favours ion production processes above ion losses at fixed height under day-light conditions.Key words: Atmospheric composition and structure (thermosphere · composition and chemistry) · Ionosphere (ionosphere · atmosphere interactions; modelling and forecasting)

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10

Bowman, G. G. "Some aspects of large-scale travelling ionospheric disturbances." Planetary and Space Science 40, no. 6 (June 1992): 829–45. http://dx.doi.org/10.1016/0032-0633(92)90110-a.

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11

Bowman, G. G., and P. E. Monro. "Mid-latitude range spread and travelling ionospheric disturbances." Journal of Atmospheric and Terrestrial Physics 50, no. 3 (March 1988): 215–23. http://dx.doi.org/10.1016/0021-9169(88)90070-0.

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12

Ashkaliev, Ya F., G. I. Gordienko, Ch Jacobi, Yu G. Litvinov, V. V. Vodyannikov, and A. F. Yakovets. "Comparison of travelling ionospheric disturbance measurements with thermosphere/ionosphere model results." Annales Geophysicae 21, no. 4 (April 30, 2003): 1031–37. http://dx.doi.org/10.5194/angeo-21-1031-2003.

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Abstract. Comparisons of modeled and measured responses of the ionosphere to the passage of atmospheric gravity waves are made for data recorded by an ionosonde located at Almaty (76°55' E, 43°15' N) from June 2000 until May 2001. Temporal variations of the altitude (hmF) and electron content (NmF) of the F-layer peak are used for comparisons. A significant part of the observations showed well-defined wave structures on the hmF, NmF and other parameter variations observed throughout the entire nights. Both the modeling study and measurements showed that, as the F-layer is lifted by the positive surge in gravity wave, the electron content at the F-layer peak decreases, with the slab thickness being increased as well. Subsequently, the opposite happens as hmF falls below its equilibrium value. Some discrepancy between the model and experimental results related to the phase difference between hmF and NmF variations is revealed.Key words. Ionosphere (ionosphere-atmosphere interaction, ionospheric disturbances)

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13

Fallows, Richard A., Biagio Forte, Ivan Astin, Tom Allbrook, Alex Arnold, Alan Wood, Gareth Dorrian, et al. "A LOFAR observation of ionospheric scintillation from two simultaneous travelling ionospheric disturbances." Journal of Space Weather and Space Climate 10 (2020): 10. http://dx.doi.org/10.1051/swsc/2020010.

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This paper presents the results from one of the first observations of ionospheric scintillation taken using the Low-Frequency Array (LOFAR). The observation was of the strong natural radio source Cassiopeia A, taken overnight on 18–19 August 2013, and exhibited moderately strong scattering effects in dynamic spectra of intensity received across an observing bandwidth of 10–80 MHz. Delay-Doppler spectra (the 2-D FFT of the dynamic spectrum) from the first hour of observation showed two discrete parabolic arcs, one with a steep curvature and the other shallow, which can be used to provide estimates of the distance to, and velocity of, the scattering plasma. A cross-correlation analysis of data received by the dense array of stations in the LOFAR “core” reveals two different velocities in the scintillation pattern: a primary velocity of ~20–40 ms−1 with a north-west to south-east direction, associated with the steep parabolic arc and a scattering altitude in the F-region or higher, and a secondary velocity of ~110 ms−1 with a north-east to south-west direction, associated with the shallow arc and a scattering altitude in the D-region. Geomagnetic activity was low in the mid-latitudes at the time, but a weak sub-storm at high latitudes reached its peak at the start of the observation. An analysis of Global Navigation Satellite Systems (GNSS) and ionosonde data from the time reveals a larger-scale travelling ionospheric disturbance (TID), possibly the result of the high-latitude activity, travelling in the north-west to south-east direction, and, simultaneously, a smaller-scale TID travelling in a north-east to south-west direction, which could be associated with atmospheric gravity wave activity. The LOFAR observation shows scattering from both TIDs, at different altitudes and propagating in different directions. To the best of our knowledge this is the first time that such a phenomenon has been reported.

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14

Fedorenko, Yu P. "Dependence of spatial periods of travelling ionospheric disturbances on their relative amplitudes." Kosmìčna nauka ì tehnologìâ 26, no. 6 (2020): 38–59. http://dx.doi.org/10.15407/knit2020.06.038.

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The relationship between the horizontal spatial period L and the relative amplitude Ad of traveling ionospheric disturbances (TID) at various levels of solar (SA) and geomagnetic (GA) activity is experimentally studied. In the vast majority of cases, the TIDs observed during our study were generated by high-latitude sources. It was found that the period L and amplitude Ad of the medium-scale (MS) TIDs (L = 100 – 800 km) are related by a linear dependence, which does not depend upon the SA level. For large-scale (LS) TID with L = 1000 – 4000 km, the linear approximation of the function L(Ad) at low and high SA levels are increasing or decreasing functions, respectively. For global-scale (GM) TIDs with L = 5000 – 35000 km at low SA levels, the linear approximation L(Ad) is an increasing function. The function L(Ad) for TIDs of all spatial scales does not depend upon the GA level. The data were collected at the radio-physical observatory of V. N. Karazin Kharkiv National University (j = 49.63°N, l = 36.32°E) in 1999—2010 with the ionosphere radio sounding by using coherent radio waves at frequencies of about 150 and 400 MHz radiated by low-orbit navigation satellites Parus and Cicada orbiting at circular near-polar orbit with a height of about 1000 km. The experimental dependence of the horizontal period L of TID upon their relative amplitude Ad is explained based on the global prognostic semi-empirical model of the generation and propagation of acoustic-gravitational waves and traveling ionospheric disturbances.

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15

Balthazor, R. L., and R. J. Moffett. "A study of atmospheric gravity waves and travelling ionospheric disturbances at equatorial latitudes." Annales Geophysicae 15, no. 8 (August 31, 1997): 1048–56. http://dx.doi.org/10.1007/s00585-997-1048-4.

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Abstract. A global coupled thermosphere-ionosphere-plasmasphere model is used to simulate a family of large-scale imperfectly ducted atmospheric gravity waves (AGWs) and associated travelling ionospheric disturbances (TIDs) originating at conjugate magnetic latitudes in the north and south auroral zones and subsequently propagating meridionally to equatorial latitudes. A 'fast' dominant mode and two slower modes are identified. We find that, at the magnetic equator, all the clearly identified modes of AGW interfere constructively and pass through to the opposite hemisphere with unchanged velocity. At F-region altitudes the 'fast' AGW has the largest amplitude, and when northward propagating and southward propagating modes interfere at the equator, the TID (as parameterised by the fractional change in the electron density at the F2 peak) increases in magnitude at the equator. The amplitude of the TID at the magnetic equator is increased compared to mid-latitudes in both upper and lower F-regions with a larger increase in the upper F-region. The ionospheric disturbance at the equator persists in the upper F-region for about 1 hour and in the lower F-region for 2.5 hours after the AGWs first interfere, and it is suggested that this is due to enhancements of the TID by slower AGW modes arriving later at the magnetic equator. The complex effects of the interplays of the TIDs generated in the equatorial plasmasphere are analysed by examining neutral and ion winds predicted by the model, and are demonstrated to be consequences of the forcing of the plasmasphere along the magnetic field lines by the neutral air pressure wave.

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16

Yizengaw, E., P. L. Dyson, E. A. Essex, and M. B. Moldwin. "Ionosphere dynamics over the Southern Hemisphere during the 31 March 2001 severe magnetic storm using multi-instrument measurement data." Annales Geophysicae 23, no. 3 (March 30, 2005): 707–21. http://dx.doi.org/10.5194/angeo-23-707-2005.

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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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17

Yakovets, A. F., M. Z. Kaliev, and V. V. Vodyannikov. "An experimental study of wave packets in travelling ionospheric disturbances." Journal of Atmospheric and Solar-Terrestrial Physics 61, no. 8 (May 1999): 629–39. http://dx.doi.org/10.1016/s1364-6826(99)00010-3.

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18

Terekhov, A. I. "Reconstruction of travelling ionospheric disturbances parameters by a tomographic method." Journal of Atmospheric and Terrestrial Physics 54, no. 10 (October 1992): 1295–302. http://dx.doi.org/10.1016/0021-9169(92)90038-m.

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19

Yakovets, A. F., V. I. Drobjev, and Yu G. Litvinov. "The spatial coherence of travelling ionospheric disturbances at mid-latitudes." Journal of Atmospheric and Terrestrial Physics 57, no. 1 (January 1995): 25–33. http://dx.doi.org/10.1016/0021-9169(93)e0014-z.

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20

Kouba, Daniel, and Jaroslav Chum. "Ground-based measurements of ionospheric dynamics." Journal of Space Weather and Space Climate 8 (2018): A29. http://dx.doi.org/10.1051/swsc/2018018.

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Different methods are used to research and monitor the ionospheric dynamics using ground measurements: Digisonde Drift Measurements (DDM) and Continuous Doppler Sounding (CDS). For the first time, we present comparison between both methods on specific examples. Both methods provide information about the vertical drift velocity component. The DDM provides more information about the drift velocity vector and detected reflection points. However, the method is limited by the relatively low time resolution. In contrast, the strength of CDS is its high time resolution. The discussed methods can be used for real-time monitoring of medium scale travelling ionospheric disturbances. We conclude that it is advantageous to use both methods simultaneously if possible. The CDS is then applied for the disturbance detection and analysis, and the DDM is applied for the reflection height control.

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21

Cazuza, Elio Pessoa, Anderson Luiz Pinheiro De Oliveira, Hadassa Raquel Peixoto Jácome, Gilvan Luiz Borba, José Pedro Silva Junior, and Manilo Soares Marques. "POSSÍVEL TID GERADO NA REGIÃO POLAR E OBSERVADO SOBRE ESTAÇÕES EQUATORIAIS E DE BAIXAS LATITUDES." HOLOS 4 (November 1, 2018): 46–61. http://dx.doi.org/10.15628/holos.2018.7108.

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Os Distúrbios Ionosféricos Propagantes (TID’s - Travelling Ionospheric Disturbances) são irregularidades no plasma ionosférico que se propagam com velocidades da ordem de dezenas a poucas centenas de quilômetros por hora. Nesse trabalho, foram detectadas e caracterizadas perturbações do tipo LSTID’s (Large scale Travelling Ionospheric Disturbances), em baixas latitudes, durante intensas tempestades geomagnéticas e também a forma como se propagação. Utilizou-se registros ionosféricos obtidos a partir de digissondas do tipo CADI (Canadian Advanced Digital Ionosonde) localizada na cidade de Natal e do tipo DSP (Digisonde Portable Souder) localizadas nas cidades de Cachoeira Paulista, Ramey e Eglin. Os dados de sondagem de Ramey e Eglin foram disponibilizados pela Global Ionosphere Radio Observatory (GIRO). Para observar os efeitos de tempestades sobre a ionosfera polar, foram utilizadas imagens aurorais do polo Norte, obtidas pelo satélite POLAR, que mostraram a intensificação do eletrojato auroral pela injeção de partículas nas cúspides. O período analisado compreendeu os dias 06 e 07 de abril de 2000 e os índices utilizados para caracterizar a atividade magnética nesse período foram Dst, Kp, e AE, além da componente Bz do campo magnético interplanetário. A tempestade ocorrida no dia 6 de abril apresentou um Dstmin = - 288 nT. A partir de gráficos de isolinhas foram verificados comportamentos anômalos da ionosfera sobre as quatro cidades, caracterizando a propagação como sendo do tipo LSTID’s, gerados pela expansão do oval auroral nos polos.

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22

Бернгардт, Олег, and Oleg Berngardt. "Space weather impact on radio device operation." Solnechno-Zemnaya Fizika 3, no. 3 (September 29, 2017): 40–60. http://dx.doi.org/10.12737/szf-33201705.

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This paper reviews the space weather impact on operation of radio devices. The review is based on recently published papers, books, and strategic scientific plans of space weather investigations. The main attention is paid to ionospheric effects on propagation of radiowaves, basically short ones. Some examples of such effects are given based on 2012–2016 ISTP SB RAS EKB radar data: attenuation of ground backscatter signals during solar flares, effects of travelling ionospheric disturbances of different scales in ground backscatter signals, effects of magnetospheric waves in ionospheric scatter signals.

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23

Belehaki, Anna, Ioanna Tsagouri, David Altadill, Estefania Blanch, Claudia Borries, Dalia Buresova, Jaroslav Chum, et al. "An overview of methodologies for real-time detection, characterisation and tracking of traveling ionospheric disturbances developed in the TechTIDE project." Journal of Space Weather and Space Climate 10 (2020): 42. http://dx.doi.org/10.1051/swsc/2020043.

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The main objective of the TechTIDE project (warning and mitigation technologies for travelling ionospheric disturbances effects) is the development of an identification and tracking system for travelling ionospheric disturbances (TIDs) which will issue warnings of electron density perturbations over large world regions. The TechTIDE project has put in operation a real-time warning system that provides the results of complementary TID detection methodologies and many potential drivers to help users assess the risks and develop mitigation techniques tailored to their applications. The TechTIDE methodologies are able to detect in real time activity caused by both large-scale and medium-scale TIDs and characterize background conditions and external drivers, as an additional information required by the users to assess the criticality of the ongoing disturbances in real time. TechTIDE methodologies are based on the exploitation of data collected in real time from Digisondes, Global Navigation Satellite System (GNSS) receivers and Continuous Doppler Sounding System (CDSS) networks. The results are obtained and provided to users in real time. The paper presents the achievements of the project and discusses the challenges faced in the development of the final TechTIDE warning system.

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24

van Velthoven, P. F. J., and T. A. Th Spoelstra. "Climatology of medium scale travelling ionospheric disturbances from radio interferometric observations." Advances in Space Research 12, no. 6 (1992): 211–14. http://dx.doi.org/10.1016/0273-1177(92)90057-5.

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25

Bolmgren, Karl, Cathryn Mitchell, Talini Pinto Jayawardena, Gary Bust, Jon Bruno, and Elizabeth Mitchell. "Tomographic imaging of a large-scale travelling ionospheric disturbance during the Halloween storm of 2003." Annales Geophysicae 38, no. 6 (November 3, 2020): 1149–57. http://dx.doi.org/10.5194/angeo-38-1149-2020.

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Abstract. The most intense ionospheric storm observed in recent times occurred between 29 and 31 October 2003. The disturbances to the high-latitude regions set off several large-scale travelling ionospheric disturbances (LSTIDs), wave-like perturbations in the ionospheric electron density. This paper investigates one particular TID on 31 October 2003 using North American Global Positioning System (GPS) receiver network data and a tomographic imaging technique. The TID has an estimated period of 30 min and an estimated horizontal wavelength of 700 km and propagates south-westward over North America. The tomographic reconstruction of the wave is validated using a simulation of the observations and with independent observations from ionosondes and the CHAMP planar Langmuir probe. The results are discussed in the context of the magnetic and ionospheric conditions that may have contributed to the launch of the wave. Large-scale TIDs are challenging to study over large regions of the Earth, and the GPS network here is shown to offer a unique perspective on the spatial and temporal variation of the TID. The experimental results are backed up by simulations that show a denser network of receivers, as is available in more recent years, would produce improved accuracy in the TID imaging.

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26

BOWMAN, G. G. "Nighttime Mid-Latitude Travelling Ionospheric Disturbances Associated with Mild Spread-F Conditions." Journal of geomagnetism and geoelectricity 43, no. 11 (1991): 899–920. http://dx.doi.org/10.5636/jgg.43.899.

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Hocke, K., and K. Schlegel. "A review of atmospheric gravity waves and travelling ionospheric disturbances: 1982–1995." Annales Geophysicae 14, no. 9 (1996): 917. http://dx.doi.org/10.1007/s005850050357.

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28

Katamzi, Z. T., N. D. Smith, C. N. Mitchell, P. Spalla, and M. Materassi. "Statistical analysis of travelling ionospheric disturbances using TEC observations from geostationary satellites." Journal of Atmospheric and Solar-Terrestrial Physics 74 (January 2012): 64–80. http://dx.doi.org/10.1016/j.jastp.2011.10.006.

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29

Waldock, J. A., and T. B. Jones. "HF Doppler observations of medium-scale travelling ionospheric disturbances at mid-latitudes." Journal of Atmospheric and Terrestrial Physics 48, no. 3 (March 1986): 245–60. http://dx.doi.org/10.1016/0021-9169(86)90099-1.

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Waldock, J. A., and T. B. Jones. "Source regions of medium scale travelling ionospheric disturbances observed at mid-latitudes." Journal of Atmospheric and Terrestrial Physics 49, no. 2 (February 1987): 105–14. http://dx.doi.org/10.1016/0021-9169(87)90044-4.

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31

ZHANG, Dong-He, K. Igarashi, Zuo XIAO, and Guan-Yi MA. "The Observation of Large Scale Travelling Ionospheric Disturbances Based on GPS Network." Chinese Journal of Geophysics 45, no. 4 (July 2002): 469–75. http://dx.doi.org/10.1002/cjg2.260.

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32

Popov, M. V., N. Bartel, M. S. Burgin, T. V. Smirnova, and V. A. Soglasnov. "Ionospheric effects in VLBI measured with space-ground interferometer RadioAstron." Monthly Notices of the Royal Astronomical Society 506, no. 3 (July 7, 2021): 4101–6. http://dx.doi.org/10.1093/mnras/stab1921.

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ABSTRACT We report on slow phase variations of the response of the space-ground radio interferometer RadioAstron during observations of pulsar B0329+54. The phase variations are due to the ionosphere and clearly distinguishable from effects of interstellar scintillation. Observations were made in a frequency range of 316–332 MHz with the 110-m Green Bank Telescope and the 10-m RadioAstron telescope in 1-h sessions on 2012 November 26, 27, 28, and 29 with progressively increasing baseline projections of about 60, 90, 180, and 240 thousand kilometres. Quasi-periodic phase variations of interferometric scintles were detected in two observing sessions with characteristic time-scales of 12 and 10 min and amplitudes of up to 6.9 radians. We attribute the variations to the influence of medium-scale Travelling Ionospheric Disturbances. The measured amplitude corresponds to variations in vertical total electron content in ionosphere of about $0.1\times 10^{16}\, \text{m}^{-2}$. Such variations would noticeably constrain the coherent integration time in VLBI studies of compact radio sources at low frequencies.

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33

Le, H., L. Liu, X. Yue, and W. Wan. "The ionospheric behavior in conjugate hemispheres during the 3 October 2005 solar eclipse." Annales Geophysicae 27, no. 1 (January 9, 2009): 179–84. http://dx.doi.org/10.5194/angeo-27-179-2009.

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Abstract. We investigate the ionospheric behavior in conjugate hemispheres during the 3 October 2005 solar eclipse, on the basis of observations of electron temperature (Te) from the Defense Meteorological Satellites Program (DMSP) spacecraft, F2 layer critical frequency (foF2) and F2 layer peak height (hmF2) at the Grahamstown ionosonde station, and total electron content (TEC) from the Global Positioning System (GPS) station SUTH. The observations show that when the eclipse occurred in the Northern Hemisphere, there was a decrease in Te, an increase in foF2 and TEC, and an uprising in hmF2 in its conjugate region compared with their reference values. We also simulated the ionosphere behavior during this eclipse using a mid- and low-latitude ionospheric model. The simulations agree well with the observations. Because of the eclipse effect, there are far fewer photoelectrons travelling along the magnetic field lines from the eclipse region to the conjugate region, resulting in reduced photoelectron heating in the conjugate hemisphere which causes a drop in electron temperature and subsequent disturbances in the region.

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34

Zakharov, V. I., and Ya A. Ilyushin. "Anthropogenic impact signatures revealed in the travelling ionospheric disturbances by regional GPS interferometry." IOP Conference Series: Earth and Environmental Science 107 (January 2018): 012081. http://dx.doi.org/10.1088/1755-1315/107/1/012081.

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35

Natorf, L., A. W. Wernik, E. B. Wodnicka, and K. Schlegel. "Detecting travelling ionospheric disturbances in incoherent scatter data using the maximum entropy method." Journal of Atmospheric and Terrestrial Physics 51, no. 5 (May 1989): 389–400. http://dx.doi.org/10.1016/0021-9169(89)90121-9.

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36

Karhunen, T. J. T., T. R. Robinson, N. F. Arnold, and M. Lester. "Determination of the parameters of travelling ionospheric disturbances in the high-latitude ionosphere using CUTLASS coherent scatter radars." Journal of Atmospheric and Solar-Terrestrial Physics 68, no. 3-5 (February 2006): 558–67. http://dx.doi.org/10.1016/j.jastp.2005.03.021.

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37

Afraimovich, E. L., A. I. Terekhov, M. Yu Udodov, and S. V. Fridman. "Refraction distortions of transionospheric radio signais caused by changes in a regular ionosphere and by travelling ionospheric disturbances." Journal of Atmospheric and Terrestrial Physics 54, no. 7-8 (July 1992): 1013–20. http://dx.doi.org/10.1016/0021-9169(92)90068-v.

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38

Beggs, H. M., and E. C. Butcher. "A study of travelling ionospheric disturbances over macquarie island using an oblique CW sounder." Planetary and Space Science 37, no. 8 (August 1989): 967–77. http://dx.doi.org/10.1016/0032-0633(89)90051-2.

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39

Hajkowicz, L. A. "Auroral electrojet effect on the global occurrence pattern of large scale travelling ionospheric disturbances." Planetary and Space Science 39, no. 8 (August 1991): 1189–96. http://dx.doi.org/10.1016/0032-0633(91)90170-f.

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40

Afraimovich, E. L., N. P. Minko, and S. V. Fridman. "Spectral and dispersion characteristics of travelling ionospheric disturbances as deduced from transionospheric sounding data." Journal of Atmospheric and Terrestrial Physics 56, no. 11 (September 1994): 1431–46. http://dx.doi.org/10.1016/0021-9169(94)90109-0.

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41

Afraimovich, E. L., and M. Yu Udodov. "Travelling ionospheric disturbances and the effectiveness of powerful HF transmitters in ionospheric modification and radio location of the Moon." Journal of Atmospheric and Terrestrial Physics 55, no. 1 (January 1993): 57–64. http://dx.doi.org/10.1016/0021-9169(93)90154-q.

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42

Muafiry, Ihsan Naufal, Irwan Meilano, Kosuke Heki, Dudy D. Wijaya, and Kris Adi Nugraha. "Ionospheric Disturbances after the 2022 Hunga Tonga-Hunga Ha’apai Eruption above Indonesia from GNSS-TEC Observations." Atmosphere 13, no. 10 (October 3, 2022): 1615. http://dx.doi.org/10.3390/atmos13101615.

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On 15 January 2022, a VEI 5 eruption occurred at the submarine Hunga Tonga-Hunga Ha’apai (HTHH) Volcano in the Southwest Pacific, causing an ash plume reaching a height of 50–55 km. The eruption generated strong acoustic-gravity waves in the near-field and stations all over the world recorded Lamb waves (LW) that travelled around the earth multiple times at a speed of ~0.3 km/s. Here we report ionospheric anomalies due to the LW over Indonesian islands, 5000–10,000 km away from the volcano, in terms of changes in total electron contents (TEC) using the nationwide network of GNSS stations. We detected ionospheric anomalies travelling above Indonesia several times both westward and eastward. The first passage of LW over Java caused strong TEC increases of >12 TECU. The wave circled the earth and returned to Java on subsequent days. The second passage was recorded early 1/17, the anomaly decayed to 6 TECU. We also detected the passage of long-path waves propagating from west to east. In addition to such anomalies, we examined the existence of ionospheric disturbances apparently propagating from the geomagnetic conjugate point of the volcano that could possibly emerge in Indonesia. However, their signatures in Indonesia were not clear.

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43

Osei-Poku, Louis, Long Tang, Wu Chen, and Chen Mingli. "Evaluating Total Electron Content (TEC) Detrending Techniques in Determining Ionospheric Disturbances during Lightning Events in A Low Latitude Region." Remote Sensing 13, no. 23 (November 24, 2021): 4753. http://dx.doi.org/10.3390/rs13234753.

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Total Electron Content (TEC) from Global Navigation Satellite Systems (GNSS) is used to ascertain the impact of space weather events on navigation and communication systems. TEC is detrended by several methods to show this impact. Information from the detrended TEC may or may not necessarily represent a geophysical parameter. In this study, two commonly used detrending methods, Savitzky–Golay filter and polynomial fitting, are evaluated during thunderstorm events in Hong Kong. A two-step approach of detection and distinguishing is introduced alongside linear correlation in order to determine the best detrending model. Savitzky–Golay filter on order six and with a time window length of 120 min performed the best in detecting lightning events, and had the highest moderate positive correlation of 0.4. That the best time frame was 120 min suggests that the observed disturbances could be travelling ionospheric disturbance (TID), with lightning as the potential source.

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44

Hawlitschka, S. "Travelling ionospheric disturbances (TIDs) and tides observed by a super-resolution HF direction finding system." Journal of Atmospheric and Solar-Terrestrial Physics 68, no. 3-5 (February 2006): 568–77. http://dx.doi.org/10.1016/j.jastp.2005.03.022.

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45

Yang, Heng, Enrique Monte Moreno, and Manuel Hernández-Pajares. "Detection and Description of the Different Ionospheric Disturbances that Appeared during the Solar Eclipse of 21 August 2017." Remote Sensing 10, no. 11 (October 30, 2018): 1710. http://dx.doi.org/10.3390/rs10111710.

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This work will provide a detailed characterization of the travelling ionospheric disturbances (TIDs) created by the solar eclipse of 21 August 2017, the shadow of which crossed the United States from the Pacific to the Atlantic ocean. The analysis is done by means of the Atomic Decomposition Detector of Traveling Ionospheric Disturbances (ADDTID) algorithm. This method automatically detects and characterizes multiple TIDs from the global navigation satellite system (GNSS) observation. The set of disturbances generated by the eclipse has a richer and more varied behavior than that associated with the shock wave directly produced by cooling effects of the moon shadow. This can be modeled in part as if the umbra and penumbra of the eclipse were moving cylinders that intersects with variable elevation angle a curved surface. This projection gives rise to regions of equal penumbra with shapes similar to ellipses, with different centers and foci. The result of this is reflected in the time evolution of the TID wavelengths produced by the eclipse, which depend on the vertical angle of the sun with the surface of the earth, and also a double bow wave phenomenon, where the bow waves are generated in advance to the umbra. We show that the delay in the appearance of the disturbances with the transit of the eclipse are compatible with the physical explanations, linked to the different origins of the disturbances and the wavelengths. Finally, we detected a consistent pattern, in location and time of disturbances in advance to the penumbra as a set of medium scale TIDs, which could be hypothesized as soliton waves of the bow wave. In all cases, the detected disturbances were checked visually on the detrended vertical total electron content (TEC) maps.

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46

Bowman, G. G., and I. K. Mortimer. "Some characteristics of large-scale travelling ionospheric disturbances and a relationship between the F<sub>2</sub> layer height rises of these disturbances and equatorial pre-sunrise events." Annales Geophysicae 28, no. 7 (July 12, 2010): 1419–30. http://dx.doi.org/10.5194/angeo-28-1419-2010.

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Abstract. Initially some characteristics of large-scale travelling ionospheric disturbances (LS-TIDs) have been discussed briefly particularly as reported in the early literature. These discussions also involve the literature on the generation of LS-TIDs at times of geomagnetic bays. Secondly, the possibility that LS-TIDs may be responsible for the F2 layer equatorial pre-sunrise height rises is investigated. Tabulations at hourly intervals of h'F at Huancayo and Washington for a Rz max period (1957–1960) have been used to identify height rises. For a three-hour interval at Huancayo h'F levels equal to or greater than 40 km of medians are used to identify the pre-sunrise height rises. Also height rises at Washington, which occurred earlier than those at Huancayo, have been considered for evidence of travelling disturbances. For 40 events analysed using geomagnetic bays and Washington height rises, a few hours before they occur at Huancayo, indicate the statistical significance of an association with LS-TIDs. Similar results of statistical significance have been obtained using Washington events and bays on average 34 h before 46 Huancayo events. These delays ranged from 29 h to 38 h. The results indicate that bays which occur the day before are responsible for LS-TIDs which encircle the earth.

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47

He, Long-Song, and Jin-Song Ping. "Occurrence of medium-scale travelling ionospheric disturbances identified in the Tasman international geospace environment radar observations." Advances in Space Research 42, no. 7 (October 2008): 1276–80. http://dx.doi.org/10.1016/j.asr.2007.06.010.

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48

Liu, J. Y., P. K. Rajesh, I. T. Lee, and T. C. Chow. "Airglow observations over the equatorial ionization anomaly zone in Taiwan." Annales Geophysicae 29, no. 5 (May 5, 2011): 749–57. http://dx.doi.org/10.5194/angeo-29-749-2011.

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Abstract. Airglow imaging at mid-latitude stations often show intensity modulations associated with medium scale travelling ionospheric disturbances (MSTID), while those carried out near the equatorial regions reveal depletions caused by equatorial plasma bubbles (EPB). Two all sky cameras are used to observe plasma depletions in the 630.0 nm emission over the equatorial ionization anomaly (EIA) region, Taiwan (23° N, 121° E; 13.5° N Magnetic) during 1998–2002 and 2006–2007. The results show EPB and MSTID depletions in different solar activity conditions. Several new features of the EPB depletions such as bifurcation, secondary structure on the walls, westward tilt, etc., are discussed in this paper. Evidence of tilted depletions with secondary structures developing on the eastern wall that later evolve to appear as bifurcations, are presented for the first time. Moreover, detail investigations are carried out using International Reference Ionosphere (IRI) model as well as the electron density from Ionosonde and Global Positioning System (GPS) Occultation Experiment (GOX) onboard FORMOSAT-3/COSMIC satellite, to understand the conditions that favor the propagation of MSTID to the latitude of Taiwan.

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49

Bowman, G. G., and I. K. Mortimer. "Some aspects of large-scale travelling ionospheric disturbances which originate at conjugate locations in auroral zones, cross the equator and sometimes encircle the earth." Annales Geophysicae 29, no. 12 (December 1, 2011): 2203–10. http://dx.doi.org/10.5194/angeo-29-2203-2011.

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Abstract. The occurrence of large-scale travelling ionospheric disturbances (LS-TIDs) has been examined. Initially some literature on their generation is considered. Travel during daylight hours and also paths which involve propagation paths towards the poles are illustrated by a few examples from the literature. A daytime ionogram recording of an LS-TID is presented and discussed as are nighttime ionogram recordings for a poleward path of propagation. The tabulations of Moscow h'F recordings around midnight are examined for significant height increases which along with geomagnetic bays some hours earlier confirm the existence of LS-TIDs. A sunspot-maximum interval is involved. Some of the Moscow events were related to bays which occurred 32 h earlier thus indicating earth encirclements. Also additional encirclements are recorded by using superposed-epoch analyses for some other events.

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50

Shiokawa, K., M. Mori, Y. Otsuka, S. Oyama, S. Nozawa, S. Suzuki, and M. Connors. "Observation of nighttime medium-scale travelling ionospheric disturbances by two 630-nm airglow imagers near the auroral zone." Journal of Atmospheric and Solar-Terrestrial Physics 103 (October 2013): 184–94. http://dx.doi.org/10.1016/j.jastp.2013.03.024.

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