Articles | Volume 38, issue 1
https://doi.org/10.5194/angeo-38-243-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/angeo-38-243-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Regular paper
| 
19 Feb 2020
Regular paper |
| 19 Feb 2020
| 19 Feb 2020
Traits of sub-kilometre F-region irregularities as seen with the Swarm satellites
Department of Physics, Mbarara University of Science and Technology, Mbarara, Uganda
Stephan Buchert
Swedish Institute of Space Physics, Uppsala, Sweden
Edward Jurua
Department of Physics, Mbarara University of Science and Technology, Mbarara, Uganda
Related authors
Sharon Aol, Stephan Buchert, Edward Jurua, and Marco Milla
Ann. Geophys., 38, 1063–1080, https://doi.org/10.5194/angeo-38-1063-2020, https://doi.org/10.5194/angeo-38-1063-2020, 2020
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Ionospheric irregularities are a common phenomenon in the low-latitude ionosphere. In this paper, we compared simultaneous observations of plasma plumes by the JULIA radar, ionogram spread F generated from ionosonde observations installed at the Jicamarca Radio Observatory, and irregularities observed in situ by Swarm to determine whether Swarm in situ observations can be used as indicators of the presence of plasma plumes and spread F on the ground.
Joachim Vogt, Octav Marghitu, Adrian Blagau, Leonie Pick, Nele Stachlys, Stephan Buchert, Theodoros Sarris, Stelios Tourgaidis, Thanasis Balafoutis, Dimitrios Baloukidis, and Panagiotis Pirnaris
Geosci. Instrum. Method. Data Syst., 12, 239–257, https://doi.org/10.5194/gi-12-239-2023, https://doi.org/10.5194/gi-12-239-2023, 2023
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Motivated by recent community interest in a satellite mission to the atmospheric lower thermosphere and ionosphere (LTI) region (100–200 km altitude), the DIPCont project is concerned with the reconstruction quality of vertical profiles of key LTI variables using dual- and single-spacecraft observations. The report introduces the probabilistic DIPCont modeling framework, demonstrates its usage by means of a set of self-consistent parametric non-isothermal models, and discusses first results.
Filomena Catapano, Stephan Buchert, Enkelejda Qamili, Thomas Nilsson, Jerome Bouffard, Christian Siemes, Igino Coco, Raffaella D'Amicis, Lars Tøffner-Clausen, Lorenzo Trenchi, Poul Erik Holmdahl Olsen, and Anja Stromme
Geosci. Instrum. Method. Data Syst., 11, 149–162, https://doi.org/10.5194/gi-11-149-2022, https://doi.org/10.5194/gi-11-149-2022, 2022
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The quality control and validation activities performed by the Swarm data quality team reveal the good-quality LPs. The analysis demonstrated that the current baseline plasma data products are improved with respect to previous baseline. The LPs have captured the ionospheric plasma variability over more than half of a solar cycle, revealing the data quality dependence on the solar activity. The quality of the LP data will further improve promotion of their application to a broad range of studies.
Joshua Dreyer, Noora Partamies, Daniel Whiter, Pål G. Ellingsen, Lisa Baddeley, and Stephan C. Buchert
Ann. Geophys., 39, 277–288, https://doi.org/10.5194/angeo-39-277-2021, https://doi.org/10.5194/angeo-39-277-2021, 2021
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Small-scale auroral features are still being discovered and are not well understood. Where aurorae are caused by particle precipitation, the newly reported fragmented aurora-like emissions (FAEs) seem to be locally generated in the ionosphere (hence,
aurora-like). We analyse data from multiple instruments located near Longyearbyen to derive their main characteristics. They seem to occur as two types in a narrow altitude region (individually or in regularly spaced groups).
Minna Palmroth, Maxime Grandin, Theodoros Sarris, Eelco Doornbos, Stelios Tourgaidis, Anita Aikio, Stephan Buchert, Mark A. Clilverd, Iannis Dandouras, Roderick Heelis, Alex Hoffmann, Nickolay Ivchenko, Guram Kervalishvili, David J. Knudsen, Anna Kotova, Han-Li Liu, David M. Malaspina, Günther March, Aurélie Marchaudon, Octav Marghitu, Tomoko Matsuo, Wojciech J. Miloch, Therese Moretto-Jørgensen, Dimitris Mpaloukidis, Nils Olsen, Konstantinos Papadakis, Robert Pfaff, Panagiotis Pirnaris, Christian Siemes, Claudia Stolle, Jonas Suni, Jose van den IJssel, Pekka T. Verronen, Pieter Visser, and Masatoshi Yamauchi
Ann. Geophys., 39, 189–237, https://doi.org/10.5194/angeo-39-189-2021, https://doi.org/10.5194/angeo-39-189-2021, 2021
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This is a review paper that summarises the current understanding of the lower thermosphere–ionosphere (LTI) in terms of measurements and modelling. The LTI is the transition region between space and the atmosphere and as such of tremendous importance to both the domains of space and atmosphere. The paper also serves as the background for European Space Agency Earth Explorer 10 candidate mission Daedalus.
Sharon Aol, Stephan Buchert, Edward Jurua, and Marco Milla
Ann. Geophys., 38, 1063–1080, https://doi.org/10.5194/angeo-38-1063-2020, https://doi.org/10.5194/angeo-38-1063-2020, 2020
Short summary
Short summary
Ionospheric irregularities are a common phenomenon in the low-latitude ionosphere. In this paper, we compared simultaneous observations of plasma plumes by the JULIA radar, ionogram spread F generated from ionosonde observations installed at the Jicamarca Radio Observatory, and irregularities observed in situ by Swarm to determine whether Swarm in situ observations can be used as indicators of the presence of plasma plumes and spread F on the ground.
Stephan C. Buchert
Ann. Geophys., 38, 1019–1030, https://doi.org/10.5194/angeo-38-1019-2020, https://doi.org/10.5194/angeo-38-1019-2020, 2020
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Winds in the Earth's upper atmosphere cause magnetic and electric variations both at the ground and in space all over the Earth. According to the model of entangled dynamos the true cause is wind differences between regions in the Northern and Southern Hemispheres that are connected by the Earth's dipole-like magnetic field. The power produced in the southern dynamo heats the northern upper atmosphere and vice versa. The dynamos exist owing to this entanglement, an analogy to quantum mechanics.
Theodoros E. Sarris, Elsayed R. Talaat, Minna Palmroth, Iannis Dandouras, Errico Armandillo, Guram Kervalishvili, Stephan Buchert, Stylianos Tourgaidis, David M. Malaspina, Allison N. Jaynes, Nikolaos Paschalidis, John Sample, Jasper Halekas, Eelco Doornbos, Vaios Lappas, Therese Moretto Jørgensen, Claudia Stolle, Mark Clilverd, Qian Wu, Ingmar Sandberg, Panagiotis Pirnaris, and Anita Aikio
Geosci. Instrum. Method. Data Syst., 9, 153–191, https://doi.org/10.5194/gi-9-153-2020, https://doi.org/10.5194/gi-9-153-2020, 2020
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Daedalus aims to measure the largely unexplored area between Eart's atmosphere and space, the Earth's
ignorosphere. Here, intriguing and complex processes govern the deposition and transport of energy. The aim is to quantify this energy by measuring effects caused by electrodynamic processes in this region. The concept is based on a mother satellite that carries a suite of instruments, along with smaller satellites carrying a subset of instruments that are released into the atmosphere.
Geoffrey Andima, Emirant B. Amabayo, Edward Jurua, and Pierre J. Cilliers
Ann. Geophys., 37, 65–76, https://doi.org/10.5194/angeo-37-65-2019, https://doi.org/10.5194/angeo-37-65-2019, 2019
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Based on hourly averages of the total electron content (TEC), a regional model of the TEC was constructed. Annual averages calculated from monthly medians of the detrended TEC were used to estimate any trends in the TEC over the African low latitudes. A predominantly negative trend in the ionospheric TEC was observed in the vicinity of the dip equator.
Patrick Mungufeni, John Bosco Habarulema, Yenca Migoya-Orué, and Edward Jurua
Ann. Geophys., 36, 841–853, https://doi.org/10.5194/angeo-36-841-2018, https://doi.org/10.5194/angeo-36-841-2018, 2018
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We have established that, over the East African region, the trough of the equatorial ionisation anomaly (EIA) during high solar activity and quiet geomagnetic conditions lies slightly south of the magnetic equator. During the equinox and December solstice seasons, and a local time interval of 13:00–15:00, the probability of observing the EIA on days with daytime equatorial electrojet (EEJ) strength ≥ 40 nT was mostly > 80 %.
J. Park, H. Lühr, C. Stolle, G. Malhotra, J. B. H. Baker, S. Buchert, and R. Gill
Ann. Geophys., 33, 829–835, https://doi.org/10.5194/angeo-33-829-2015, https://doi.org/10.5194/angeo-33-829-2015, 2015
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Though high-latitude plasma convection has been monitored with a number of methods, more independent measurements are still warranted. In this study we introduce an automatic method to estimate along-track plasma drift velocity in the high-latitude ionosphere using the Swarm constellation. The obtained velocity is in qualitative agreement with Super Dual Auroral Radar Network (SuperDARN) data. The method can be generalized to any satellite constellations in pearls-on-a-string configurations.
T. Živković, S. Buchert, P. Ritter, L. Palin, and H. Opgenoorth
Ann. Geophys., 33, 623–635, https://doi.org/10.5194/angeo-33-623-2015, https://doi.org/10.5194/angeo-33-623-2015, 2015
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In this paper we analyze 21 conjunctions between the Cluster and CHAMP satellites while they were passing magnetic cusp during relatively quiet solar activity. Only three of the conjunctions reveal field-aligned currents on both satellites as well as neutral density enhancement in the thermosphere. Poynting and electron energy fluxes (EEF) as well as Joule heating were computed and the conclusion is that for these weak events EEF has the strongest contribution to the observed density increase.
Related subject area
Subject: Earth's ionosphere & aeronomy | Keywords: Ionospheric irregularities
Simultaneous OI 630 nm imaging observations of thermospheric gravity waves and associated revival of fossil depletions around midnight near the equatorial ionization anomaly (EIA) crest
F-region drift current and magnetic perturbation distribution by the X-wave heating ionosphere
Fluid models capturing Farley–Buneman instabilities
Temporal and altitudinal variability of the spread F observed by the VHF radar over Christmas Island
Effect of neutral winds on the creation of non-specular meteor trail echoes
Simultaneous ground-based and in situ Swarm observations of equatorial F-region irregularities over Jicamarca
Occurrence climatology of equatorial plasma bubbles derived using FormoSat-3 ∕ COSMIC GPS radio occultation data
Localized total electron content enhancements in the Southern Hemisphere
Stratification observed by the in situ plasma density measurements from the Swarm satellites
Structural characterization of the equatorial F region plasma irregularities in the multifractal context
Equatorial plasma bubbles developing around sunrise observed by an all-sky imager and global navigation satellite system network during storm time
Investigation of the relationship between the spatial gradient of total electron content (TEC) between two nearby stations and the occurrence of ionospheric irregularities
Research on small-scale structures of ice particle density and electron density in the mesopause region
On developing a new ionospheric plasma index for Brazilian equatorial F region irregularities
Observation of seasonal asymmetry in the range spread F occurrence at different longitudes during low and moderate solar activity
Identifying a possible stratification phenomenon in ionospheric F2 layer using the data observed by the DEMETER satellite: method and results
Global sounding of F region irregularities by COSMIC during a geomagnetic storm
On the convection of ionospheric density features
The ionospheric response over the UK to major bombing raids during World War II
Navin Parihar, Saranya Padincharapad, Anand Kumar Singh, Prasanna Mahavarkar, and Ashok Priyadarshan Dimri
Ann. Geophys., 42, 131–143, https://doi.org/10.5194/angeo-42-131-2024, https://doi.org/10.5194/angeo-42-131-2024, 2024
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Gravity waves are well known for deforming the bottom-side plasma of the F region into the wavelike ionization structures which then act as a seed for Rayleigh–Taylor instability, which in turn generates irregularities. The present study features midnight fossil airglow depletions that revived due to ongoing gravity wave (GW) activity and turned into an active depletion.
Yong Li, Hui Li, Jian Wu, Xingbao Lv, Chengxun Yuan, Ce Li, and Zhongxiang Zhou
Ann. Geophys., 41, 541–549, https://doi.org/10.5194/angeo-41-541-2023, https://doi.org/10.5194/angeo-41-541-2023, 2023
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According to plasma drift theory, charged particles will drift when they are subjected to external forces, thus generating a drift current. In this paper, we establish the drift current and magnetic perturbation model in the ionosphere. Based on the HAARP ionospheric background, we analyze the properties of drift current and magnetic perturbation. This work provides guidance for a better understanding of ionospheric current distributions and magnetic perturbations.
Enrique L. Rojas, Keaton J. Burns, and David L. Hysell
Ann. Geophys., 41, 281–287, https://doi.org/10.5194/angeo-41-281-2023, https://doi.org/10.5194/angeo-41-281-2023, 2023
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The standard linear fluid theory of Farley and Buneman predicts that kinetic physics are required to avoid the artificial growth of smaller structures. We explore the possibility of simulating the Farley–Buneman instability using, for the first time, a fully fluid five-moment model. This is the first time a fully fluid model has been used to simulate the Farley–Buneman instability. The results obtained with both models are qualitatively consistent with the ones from kinetic simulations.
Ricardo Yvan de La Cruz Cueva, Eurico Rodrigues de Paula, and Acácio Cunha Neto
Ann. Geophys., 40, 563–570, https://doi.org/10.5194/angeo-40-563-2022, https://doi.org/10.5194/angeo-40-563-2022, 2022
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This paper brings analysis of spread-F echoes along the years of 2003 to 2012 from Christmas Island radar. We organize our data with the objective of observing the peak time and altitude distribution. Our results indicate the peak time occurrence of echoes to be distributed closer to local sunset during solar maximum and around midnight during solar minimum; meanwhile, the peak altitude echoes show higher altitude occurrences during solar maxima and lower altitudes during solar minima.
Freddy Galindo, Julio Urbina, and Lars Dyrud
Ann. Geophys., 39, 709–719, https://doi.org/10.5194/angeo-39-709-2021, https://doi.org/10.5194/angeo-39-709-2021, 2021
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Micro-size particles entering the Earth’s atmosphere do not emit enough light to be observed as meteors, but they can be probed with radars. The echo from these meteors depends on particle size and the atmosphere in which the particle travels. In this paper, we study the importance of neutral winds in forming meteor returns sensed by radars. We show that meteor trails can exhibit unique radar signatures due to neutral winds, explaining unique signatures in radar maps.
Sharon Aol, Stephan Buchert, Edward Jurua, and Marco Milla
Ann. Geophys., 38, 1063–1080, https://doi.org/10.5194/angeo-38-1063-2020, https://doi.org/10.5194/angeo-38-1063-2020, 2020
Short summary
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Ionospheric irregularities are a common phenomenon in the low-latitude ionosphere. In this paper, we compared simultaneous observations of plasma plumes by the JULIA radar, ionogram spread F generated from ionosonde observations installed at the Jicamarca Radio Observatory, and irregularities observed in situ by Swarm to determine whether Swarm in situ observations can be used as indicators of the presence of plasma plumes and spread F on the ground.
Ankur Kepkar, Christina Arras, Jens Wickert, Harald Schuh, Mahdi Alizadeh, and Lung-Chih Tsai
Ann. Geophys., 38, 611–623, https://doi.org/10.5194/angeo-38-611-2020, https://doi.org/10.5194/angeo-38-611-2020, 2020
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The paper focuses on the analyses of the global occurrence of equatorial plasma bubble events using S4 data that were calculated from GPS radio occultation measurements of the FormoSat-3/COSMIC mission. The advantage in using radio occultation data is that we get information not only on the occurrence and intensity of the equatorial bubble events, but also on the altitude distribution. We analyzed a 10.5-year time series of COSMIC data and demonstrated a strong dependence on the solar cycle.
Ilya K. Edemskiy
Ann. Geophys., 38, 591–601, https://doi.org/10.5194/angeo-38-591-2020, https://doi.org/10.5194/angeo-38-591-2020, 2020
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This paper investigates a feature in the Southern Hemisphere ionosphere that is observed near midday in the form of a localized enhancement of the electron density. After being discovered in global ionospheric maps, the enhancements were also observed via in situ measurements of the electron concentration. The probability of detecting an enhancement is maximal during the autumn–winter period and does not seem to be directly dependent on geomagnetic indices or solar wind parameters.
Xiuying Wang, Wanli Cheng, Zihan Zhou, Dehe Yang, Jing Cui, and Feng Guo
Ann. Geophys., 38, 517–526, https://doi.org/10.5194/angeo-38-517-2020, https://doi.org/10.5194/angeo-38-517-2020, 2020
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To get the global distribution of the stratification phenomenon, the in situ plasma density measurements, obtained by the Swarm satellites orbiting at different altitudes above the F2 peak, are used to study this phenomenon. The continuous morphology of this phenomenon and its features along the latitudinal direction are obtained, and a new discovery from the in situ measurements is the stratification on southern mid-latitudes.
Neelakshi Joshi, Reinaldo R. Rosa, Siomel Savio, Esfhan Alam Kherani, Francisco Carlos de Meneses, Stephan Stephany, and Polinaya Muralikrishna
Ann. Geophys., 38, 445–456, https://doi.org/10.5194/angeo-38-445-2020, https://doi.org/10.5194/angeo-38-445-2020, 2020
Kun Wu, Jiyao Xu, Xinan Yue, Chao Xiong, Wenbin Wang, Wei Yuan, Chi Wang, Yajun Zhu, and Ji Luo
Ann. Geophys., 38, 163–177, https://doi.org/10.5194/angeo-38-163-2020, https://doi.org/10.5194/angeo-38-163-2020, 2020
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An equatorial plasma bubble (EPB) event, emerging near dawn and developing after sunrise, was simultaneously observed by an all-sky imager and the global navigation satellite system (GNSS) network. The observed EPBs showed westward drifts, different from post-sunset EPBs. The EPBs occurred in the recovery phase of a geomagnetic storm, possibly playing a key role in initializing their developments. The results provide a new perspective of EPBs, enriching our knowledge of ionospheric irregularity.
Teshome Dugassa, John Bosco Habarulema, and Melessew Nigussie
Ann. Geophys., 37, 1161–1180, https://doi.org/10.5194/angeo-37-1161-2019, https://doi.org/10.5194/angeo-37-1161-2019, 2019
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The relation between the occurrence of ionospheric irregularities and the spatial gradient of TEC derived from two closely located stations, located within the equatorial region over Ethiopia, was investigated. The relationship between σ(∆TEC/∆long) and ROTIave correlate linearly with correlation coefficients of C = 0.7975 and C = 0.7915 over ASAB and DEBK, respectively. In addition to latitudinal gradients, the longitudinal gradient of TEC has a significant contribution to the TEC fluctuations.
Ruihuan Tian, Jian Wu, Jinxiu Ma, Yonggan Liang, Hui Li, Chengxun Yuan, Yongyuan Jiang, and Zhongxiang Zhou
Ann. Geophys., 37, 1079–1094, https://doi.org/10.5194/angeo-37-1079-2019, https://doi.org/10.5194/angeo-37-1079-2019, 2019
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The density distribution of ice particles and electrons near the boundary of the polar mesosphere summer echo (PMSE) region is studied. The results show that when the radius distribution function of the condensation nucleus is a Gaussian type, for a certain range of the condensation core radius, sharp peaks with a meter scale appear in the density profiles of ice particles and electrons. These small-scale structures of electron density may be one of the causes of the PMSE phenomenon.
Laysa Cristina Araujo Resende, Clezio Marcos Denardini, Giorgio Arlan Silva Picanço, Juliano Moro, Diego Barros, Cosme Alexandre Oliveira Barros Figueiredo, and Régia Pereira Silva
Ann. Geophys., 37, 807–818, https://doi.org/10.5194/angeo-37-807-2019, https://doi.org/10.5194/angeo-37-807-2019, 2019
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The Brazilian Space Weather Study and Monitoring Program (Embrace) has been developing different indexes that describe ionospheric effects in the Brazilian sector. The main purpose of this work was to produce a new ionospheric scale based on the analysis of the ionospheric plasma drift velocity. We analyzed 7 years of data in order to construct a standardized scale. The results of this new index allow us to evaluate the impacts of ionospheric phenomena in the space weather environment.
Abimbola O. Afolayan, Mandeep Jit Singh, Mardina Abdullah, Suhaila M. Buhari, Tatsuhiro Yokoyama, and Pornchai Supnithi
Ann. Geophys., 37, 733–745, https://doi.org/10.5194/angeo-37-733-2019, https://doi.org/10.5194/angeo-37-733-2019, 2019
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The equatorial spread F (ESF) is a nighttime phenomenon that can have a deleterious effect on the radio communication system. We investigated the parameters influencing the seasonal morphology of the range type spread F (RSF) using ionosonde data from different longitude sectors. The observed RSF occurrence features showed distinct patterns across these sectors, including seasonal asymmetry. This asymmetry was attributed to the probable effect of the zonal wind reversal and gravity waves.
Xiuying Wang, Dehe Yang, Dapeng Liu, and Wei Chu
Ann. Geophys., 37, 645–655, https://doi.org/10.5194/angeo-37-645-2019, https://doi.org/10.5194/angeo-37-645-2019, 2019
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To check the difference between data observed at different altitudes of the DEMETER satellite, a statistical method is adopted to evaluate whether data difference is caused by normal data fluctuation or by altitude adjustment. Based on the method, in situ electron density data at higher altitudes are found to be greater than those at lower altitudes. We speculate that this phenomenon is caused by stratification above F2 peak region. The proposed method is useful when comparing fluctuated data.
Klemens Hocke, Huixin Liu, Nicholas Pedatella, and Guanyi Ma
Ann. Geophys., 37, 235–242, https://doi.org/10.5194/angeo-37-235-2019, https://doi.org/10.5194/angeo-37-235-2019, 2019
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The GPS radio occultation data of the COSMIC-FORMOSAT-3 mission are used to visualize the global distribution of ionospheric irregularities in the F2 region during a geomagnetic storm, at solar minimum, and at solar maximum.
John D. de Boer, Jean-Marc A. Noël, and Jean-Pierre St.-Maurice
Ann. Geophys., 37, 201–214, https://doi.org/10.5194/angeo-37-201-2019, https://doi.org/10.5194/angeo-37-201-2019, 2019
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Modelling aurorae, we asked what boundary condition (BC) to use for the E field on the upper boundary. Typically a Dirichlet BC is used, since processes above the domain generate E. But then conductivity structures trigger FACs driven immediately by magnetospheric convection, even though it is a finite energy source, delayed by the Alfvén speed. If the BC is not ideal, then E x B drift in the ionosphere depends on the plasma's properties. So we investigated.
Christopher J. Scott and Patrick Major
Ann. Geophys., 36, 1243–1254, https://doi.org/10.5194/angeo-36-1243-2018, https://doi.org/10.5194/angeo-36-1243-2018, 2018
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The variability of the Earth's ionosphere (the electrified region of the Earth's upper atmosphere) results from external forcing from above (through solar activity and space weather effects) and from below (via natural sources such as lightning storms and tectonics). Bombing raids over Europe during World War II were used to determine the quantitative impact of explosions on the ionosphere. It was found that raids using more than 300 tonnes of explosives weakened the ionosphere for up to 5 h.
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Short summary
During the night, in the F region, equatorial ionospheric irregularities manifest as plasma depletions observed by satellites and may cause radio signals to fluctuate. We checked the distribution traits of ionospheric F-region irregularities in the low latitudes using 16 Hz electron density observations made by the faceplate onboard Swarm satellites. Using the high-resolution faceplate data, we were able to identify ionospheric irregularities of scales of only a few hundred metres.
During the night, in the F region, equatorial ionospheric irregularities manifest as plasma...
