Session SWR4 - Magnetosphere, Ionosphere and Thermosphere Coupling
Lucilla Alfonsi, onsite (Istituto Nazionale di Geofisica e Vulcanologia, Italy), Yaqi Jin, onsite (University of Oslo, Norway), Eelco Doornbos, onsite (Royal Netherlands Meteorological Institute (KNMI), The Netherlands)
The session focuses on the state-of-the-art understanding of the complex mechanisms ruling the Magnetosphere-Ionosphere-Thermosphere (M-I-T) coupling and how it translates into space weather impacts. Such an understanding is fundamental for the development of effective countermeasures against disruption, failure and deterioration of vulnerable technologies, such as GNSS critical applications, HF/VHF/UHF radio communications and LEO satellites operations. In order to forecast, warn, and mitigate adverse space weather effects, a better understanding of the M-I-T coupling plays a key role. It is essential to improve the prediction of: geomagnetic storm-time behaviour of the occurrence of spread-F, polar cap patches and scintillation phenomena that can degrade navigation and communication systems, thermospheric density variability affecting satellite drag and the enhancement of field-aligned currents, just to mention a few examples. Another crucial aspect of M-I-T coupling is the interhemispheric symmetric/asymmetric response to variable drivers that, if properly predicted, could support regional space weather modelling. Contributed papers may address (but are not limited to) recent developments in modelling and forecasting, monitoring methodologies, data analysis, measurement campaigns and international initiatives related to M-I-T coupling and associated threats on systems, at regional and global scale.
Poster ViewingThursday October 27, 08:30 - 13:30, Poster Area Talks Tuesday October 25, 13:30 - 14:45, Earth Hall Wednesday October 26, 14:15 - 15:15, Water Hall Thursday October 27, 14:15 - 15:30, Earth Hall Click here to toggle abstract display in the schedule
Talks : Time scheduleTuesday October 25, 13:30 - 14:45, Earth Hall| 13:30 | A novel technique to identify scale-dependent lags and application to ionospheric science | Urbář, J et al. | Oral | | | Jaroslav Urbář[1,2], Luca Spogli[1,3], Antonio Cicone[1,4,5], Claudio Cesaroni[1] and Lucilla Alfonsi[1] | | | [1]Istituto Nazionale di Geofisica e Vulcanologia, Italy; [2]Institute of Atmospheric Physics, Czech Republic; [3]SpacEarth Technology, Italy; [4]DISIM University of L’Aquila, Italy; [5]Istituto di Astrofisica e Planetologia Spaziali, INAF, Italy | | | The ionosphere is a dynamical system exhibiting nonlinear couplings with the other “spheres” characterizing the geospace environment. Such nonlinearity manifests also through the non-trivial, scale-dependent, time delays in the cause-effect chain characterizing the Solar Wind-Magnetosphere-Ionosphere coupling.
The present study uses the Intrinsic Mode Cross Correlation (IMXC): a novel scale-wise signal lag measurement, conceived to possibly identify scale-dependent lags (Urbar et al., 2021). The method performance is evaluated first on known artificial signals and then applied to ionospheric data, mainly in situ electron density from Swarm constellation. The IMXC relies on non-linear non-stationary signal decomposition provided by the novel Multivariate Fast Iterative Filtering (MvFIF) technique (Cicone&Pellegrino, 2019), which identifies the common scales embedded in the signals. The lags are then obtained scale-wise, enabling the identification of the lag dependence on the involved spatio/temporal scales for the artificial data set (even in presence of high levels of noise), and to estimate them in a real-life signal.
As the first real-life scenario assuming cause-effect relationship, we use the closely separated measurements of the European Space Agency’s Swarm Alpha (A) and Charlie (C) satellites with identical Langmuir probe instruments sampling the ionospheric plasma density in the topside ionosphere. The latitudinal orbital separation between Swarm A and C is about 8.8 s between the two satellites. By using IMXC technique, we can extract the 8.8 s seconds lag from the electron density measurements, as demonstrated in a case event.
As an example of an additional application to demonstrate the usability of the technique in the Space Weather context, we evaluate lags of the intensifications in the common scales between the electron density measurements and the field-aligned current measurements from Swarm FAC dataset again by comparing the leading and trailing satellite (Swarm A-C pair) in the high latitude regions. This can pave the way to future uses of this technique in contexts in which the causation chain can be hidden in a complex, multiscale coupling of the investigated features.
This work is performed within the Swarm Variability of Ionospheric Plasma (Swarm-VIP) project, funded by ESA in the “Swarm+4D-Ionosphere” framework (ESA Contract No. 4000130562/20/I-DT). | | 13:45 | Forecasting the Orbit Decay of low Earth orbiting satellites | Drescher, L et al. | Oral | | | Lukas Drescher[1], Sofia Kroisz[1], Manuela Temmer[1], Sandro Krauss[2], Barbara Suesser-Rechberger[2], Saniya Behzadpour[2], Torsten Mayer-Guerr[2] | | | [1]Institute of Physics, University of Graz; [2]Institute of Geodesy, Graz University of Technology | | | Geomagnetic storms occur rather consistently in accordance with the 11-year solar cycle and have the capability to trigger atmospheric disturbances and subsequently influence the trajectories of Earth orbiting satellites. The strongest disturbances of the space environment are primarily caused by interplanetary coronal mass ejections (ICMEs). We calculate thermospheric densities based on kinematic orbit information and accelerometer measurements, to investigate the disturbances of the Earth`s upper atmosphere. Depending on the density variation induced by the ICME it is possible to calculate the occurring satellite orbit decay. We relate the solar wind plasma and magnetic field measurements at L1 from the ACE and DSCOVR satellites of 299 ICMEs that were identified between 2002 to 2017 to the calculated orbit decay of the GRACE satellite in an altitude of 490 km. The correlation is implemented in the real time forecasting tool SODA (Satellite Orbit DecAy). By taking into consideration the delayed response of the thermosphere, the lead time for the start of the atmospheric perturbation will be up to ~ 18 hours. Additionally, we are working on constructing kinematic orbits for satellites in various heights so we will be able to cover altitudes between 300 to 800 km and a wider timeframe.
The forecast algorithm is part of the project SWEETS (Space Weather Effects on low Earth orbiting Satellites), a joint study between the TU Graz and University of Graz, which will be implemented in the ESA Space Safety Program (Ionospheric Weather Expert Service Center).
| | 14:00 | Local Joule heating profile near small scale auroral features estimated using high resolution electric fields measurements | Krcelic, P et al. | Oral | | | Patrik Krcelic[1], Robert Fear[1], Daniel Whiter[1], Betty Lanchester[1] | | | [1] University of Southampton | | | We use a combination of ASK, HiTIES and EISCAT measurements to estimate the local Joule heating profile near highly dynamic small scale auroral features during an event on February 2nd 2017. ASK consists of 3 cameras each having a narrow band filter centred around different distinct auroral emissions. The ratios of various measured emissions, as well as careful modelling of auroral features, allow us to estimate localised electric fields on a sub second resolution. HiTIES is a spectrograph measuring auroral emissions including N2 1P. The obtained N2 spectrum is dependent on the atmospheric neutral temperature, which is estimated from fitting of synthetic spectra to the measured one. From EISCAT measurements we use profiles of electron densities as well as ion and electron temperatures. All measurements are taken from the same, narrow field of view. We use a horizontal wind model (HWM14) to provide the neutral wind profiles. Results show little dependence of the local Joule heating profile on the neutral wind profile. Our reasoning is that electric fields near auroral features have such high intensity and variability compared to the more stable neutral wind that the E-fields dominate the calculation of the Joule heating rate. Furthermore, our Joule heating estimates are significantly larger (up to 100 times higher) than those estimated with more broad, lower resolution measurements. Such intense local heating in the auroral region may play an important role in the ionosphere and must be further researched. | | 14:15 | Swarm-VIP: a model for Variability of Ionospheric Plasma based on data from the Swarm satellites | Miloch, W et al. | Oral | | | Alan G. Wood[1], Elizabeth Donegan-Lawley[1], Gareth Dorrian[1], James Rawlings[2], Golnaz Sahtahmassebi[2], Lucilla Alfonsi[3], Luca Spogli[3,4], Jaroslav Urbář[3], Claudio Cesaroni[3], Antonio Cicone[5], Lasse B.N. Clausen[6], Yaqi Jin[6], Daria Kotova[6], Per Høeg[6], María José Brazal Aragón[7], Paweł Wojtkiewicz[7], Wojciech J. Miloch[6] | | | [1]School of Engineering, University of Birmingham, UK, [2]School of Science & Technology, Nottingham Trent University, Nottingham, UK, [3]Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy, [4]SpacEarth Technology, Rome, Italy, [5]DISIM, Università degli Studi dell'Aquila, L'Aquila, Italy, [6]Department of Physics, University of Oslo, Oslo, Norway, [7]GMV Innovating Solutions Sp. z o.o., Warsaw, Poland | | | The variability and structuring of the Earth’s ionosphere and its actual state are important aspects of the space weather system. Their good understanding is crucial for building the capability of predicting and mitigating severe space weather effects. For example, ionospheric irregularities can lead to degradation of transionospheric radio waves, and thus they can impact communication or positioning with the Global Navigation Satellite Systems (GNSS).
Through the project Swarm Variability of Ionospheric Plasma (Swarm-VIP), as a part of the Swarm+ 4DIonosphere initiative, we have analyzed spatiotemporal characteristics of ionospheric plasma at different geomagnetic latitudes, and we have developed a semi-empiric model for the ionosphere based on the generalized linear modeling. The project employed data from the European Space Agency’s Swarm satellites, such as the IPIR dataset [1], as well as auxiliary datasets. The Swarm-VIP model determines the probability of occurrence of different scales in ionospheric plasma with respect to geomagnetic conditions and the magnetosphere-ionosphere coupling. It also identifies the dominant driving processes at low, middle, auroral and polar latitudes, and can give insight into ionospheric structuring and coupling between scales. The model is provided globally, along the whole orbits of the Swarm satellites, and the validation study has been carried out with a network of ground-based instruments. We present the workings of the model, its validation, and compare it with other existing models of the ionosphere highlighting its added value.
The Swarm VIP project is funded by the European Space Agency’s in the Swarm+ 4DIonosphere framework (Contract No. 4000130562/20/I-DT).
Reference:
[1] Y. Jin, D. Kotova, Ch. Xiong, S. M. Brask, L.B.N. Clausen, G. Kervalishvili, C. Stolle, W.J. Miloch, Ionospheric Plasma IRregularities - IPIR - data product based on data from the Swarm satellites, J. Geophys. Res. 127, e2021JA030183, https://doi.org/10.1029/2021JA030183 (2022).
| | 14:30 | Predictability of Large Scale Travelling Ionospheric Disturbances During Ionosphere Storm Conditions | Borries, C et al. | Oral | | | Claudia Borries[1], Arthur Amaral Ferreira[1], Renato Alves Borges[2] | | | [1], German Aerospace Center, Institute for Solar-Terrestrial Physics, Neustrelitz, Germany, [2] Universidade de Brasília: Brasilia, DF, Brazil | | | The conditions in the thermosphere and ionosphere are impacting many technological systems like global navigation systems and satellite orbit prediction and the performance of satellite communication links. Therefore, appropriate monitoring and prediction of disturbances is very important. Especially during the passage of disturbances in the solar wind and interplanetary magnetic field, large amounts of energy are transferred into the Earth system and the thermosphere-ionosphere system gets severely disturbed. Strong electric fields and sudden intensive thermosphere heating in the auroral region are major forces driving significant changes in the thermosphere-ionosphere system. A typical phenomenon during these storm conditions are large scale atmospheric gravity waves, which are generated by the heating processes in the auroral region and propagate equatorward. Because they are carrying energy and momentum, they are supposed to play an important role in the generation of storm time ionosphere disturbances on a global scale. Commonly, these large-scale atmospheric gravity waves are measured and analysed via their ionosphere signature, the Large Scale Travelling Ionospheric Disturbances (LSTIDs). There exist more than two decades of Global Navigation Satellite System (GNSS) data from hundreds of ground stations, which are used for statistical analysis. Here, we are presenting correlation studies of LSTIDs with solar wind and geomagnetic activity parameters and demonstrate their predictability for the European region. |
Wednesday October 26, 14:15 - 15:15, Water Hall| 14:15 | A new method to monitor LEO satellite drag in near real time | Kosch, M et al. | Oral | | | Michael Kosch[1] and Emma Bland[2] | | | [1]South African National Space Agency; [2]The University Centre in Svalbard | | | Using the ion-momentum equation in the F-region ionosphere, we derive an expression for the ion-neutral collision frequency that depends primarily on the neutral density in the thermosphere. SuperDARN radars are very well suited to this type of observation because of their near real time large spatial coverage of the high-latitude F-region ionosphere. SuperDARN is an international consortium of 35 radars in both hemispheres, each covering a million square kilometres with 2-minute time resolution at 200-400 km altitude. We present results from a proof-of-principle experiment run on the Svalbard SuperDARN radar, which shows excellent agreement with the MSIS model for low geomagnetic activity.
| | 14:30 | Reconstruction of precipitated electron fluxes using auroral data | Robert, E et al. | Oral | | | [1] Elisa Robert, [2] Mathieu Barthelemy, [3] Gael Cessateur, [4] Hervé Lamy, [5] Simon Bouriat, [6] Angélique Woelfflé, [7] Lionel Birée, [8] Urban Brändstörm and [9] Magnar Gullikstad Johnsen | | | [1] IPAG, SpaceAble ; [2] IPAG, CSUG; [3] BIRA-IASB; [4] BIRA-IASB; [5] IPAG, SpaceAble ; [6] SpaceAble; [7] SpaceAble; [8] Swedish Institute of Space Physics; [9] Tromsø Geophysical Observatory | | | Precipitations of auroral electrons characterize the relationship of the magnetosphere and the upper atmosphere, therefore state of near-Earth space depending on their localization and their intensity. One of the main gaps in both data and modelling is the monitoring of the precipitation of low-energy (0.02 – 35 keV) particles in the ionosphere. These particles are responsible of the surface charging on satellites, which lead to trigger electrostatic discharge (ESD) on components. This impact is the most recurrent in space and need to better understand. The method present here, allows an alternative to particle detectors that do not have access to this area.
From optical data, it can be very interesting to reconstruct low energy electron flux in the aurora region. Therefore, the interpretation of the auroral intensities is made using the Transsolo code, a kinetic code which use as input the electron flux and the solar EUV flux on the dayside. It calculates the transport of the suprathermal electrons along a line of sight or a vertical and the subsequent auroral emissions. A optimization method is worked to trying to retrieve electron flux from optical measurements.
The study present here is based on ALIS network data which provides very useful data (Brändstörm, 2003). Tomographic data of the volume emission rate are built from ALIS measurements (Gustavsson, 2000). From tomographic data and transsolo simulations, we adapt the optimization method to reconstruct energetic particles flux. We focus on measurements of the event of 07 March 2008 at 19:01:25 UT and 20:32:00 UT acquired by 5 stations and centered above Skibotn city. Results are presented in the form of maps of mean energy and total energy (corresponding to the energy flux) depending on geographic coordinates. Maps interpretations will be given during the presentation. | | 14:45 | Study on the NeQuick-G ionospheric model efficiency on navigation positioning based on Galileo observations | Woźniak, P et al. | Oral | | | Anna Świątek [1], Paulina Woźniak [1] | | | [1] Space Research Centre, Polish Academy of Sciences, Bartycka 18A, Warsaw, 00-716, Poland | | | Measurements using GNSS (Global Navigation Satellite Systems) are affected by a number of various factors, of which the ionosphere has the greatest influence. For the electromagnetic waves in the microwave band, including UHF (Ultra High Frequency) waves transmitted by navigation satellites, the ionosphere is a dispersive medium and has a significant impact on the positioning accuracy.
To compensate for the ionospheric refraction, ionosphere models are used in the case of single-frequency observations or so-called iono-free combination for multi-frequencies measurements. In this study, the following models were adopted for the first approach: a computationally simple Klobuchar model, a model developed by an analysis centre belonging to IGS (International GNSS Service) and ultimately, the target NeQuick-G model, broadcasted by Galileo satellites. While considering the second method, used as a reference for model-based solutions, the calculations were performed for the Galileo frequency combinations: E1 and E5a as well as E1 and E5b.
The subject of research is the position of selected globally distributed stations attending the GRC-MS (Galileo Reference Centre – Member States) project and observing Galileo signal, and the aim is to analyse horizontal and vertical errors, which are among the KPIs (Key Performance Indicators). The period under examination covers the years 2019-2021, in addition, selected periods of low and high ionosphere activity were examined in detail.
Furthermore, the ionospheric models themselves were subjected to detailed analysis, both in global and local terms for selected locations. Joint consideration of NeQuick-G solutions and station positions calculated on its basis allows for the identification of its pros and cons depending on time and location. | | 15:00 | Statistical studies of plasma structuring in the auroral ionosphere by in-situ measurements | Buschmann, L et al. | Oral | | | Lisa Buschmann [1], Andres Spicher [2], Sigvald Marholm [3], Lasse B.N. Clausen [1], Wojciech J. Miloch [1] | | | [1] Department of Physics, University of Oslo, Oslo, Norway, [2] Department of Physics and Technology, UiT - The Arctic University of Norway, Tromsø, Norway, [3] Department of Computational Materials Processing, Institute for Energy Technology, Kjeller, Norway | | | The plasma in the cusp ionosphere is subject to auroral particle precipitation, which is thought to be an important source of plasma irregularieties at large scales and long lifetimes. These irregularities can be broken down to smaller scale structures which have been been linked to scintillations, i.e. fluctuations in transionospheric radio waves. We present power spectra of plasma irregularities found in the polar cusp ionosphere for regions with and without electron precipitation. Our analysis is based on the in-situ measurements from the Twin Rockets to Investigate Cusp Electrodynamics-2 (TRICE-2) mission, consisting of two sounding rockets which are flying simultaneously at two different altitudes. We used the electron density measurements from the multi-needle Langmuir probe (m-NLP) systems that were installed on both sounding rockets and analyzed for the whole flight duration for both rockets. Due to the high sampling rate of the m-NLP, the probes allow for a study of plasma density irregularities all the way down to kinetic scales.
A steepening of the slope in the power spectra indicates two regimes, a shallow region, where fluid-like processes are dominating, and a steeper region which can be addressed with kinetic theory. The steepening occurs at frequencies similar to that of the oxygen gyrofrequency and at an increased rate where precipitation starts. In addition, strong electron density fluctuations were found in regions poleward of the cusp, thus in regions immediately after precipitation and in regions where only little or no precipitation was detected.
Integrated power obtained from the power spectra shows very little fluctuations, and no dependence on altitude, for low frequencies.
For high frequencies, fluctuations in higher altitudes coincide with the passing through a flow channel with similar elevations for all frequency intervals, while in lower altitudes fluctuations appear mainly during precipitation, especially for frequency intervals within 100-300Hz.
Additionally, we used the 16-Hz sampling rate electron density measurements from the Swarm advanced data set from the Swarm mission, in order to do long-term statistics. Statistical analysis of the power spectra obtained from the Swarm data shows an asymmetry of the occurrence rate of double slopes between the southern and northern hemispheres for solar minimum, however, there seems to be no such asymmetry for solar maximum. |
Thursday October 27, 14:15 - 15:30, Earth Hall| 14:15 | Long Term Statistical Space Weather Analysis | Sado, P et al. | Oral | | | Pascal Sado[1],Lasse B. N. Clausen[1],Wojciech J. Miloch[1],Hannes Nickisch[2] | | | [1]Department of Physics, University of Oslo, Oslo, Norway, [2]Philips Research, Hamburg, Germany | | | Long Term Statistical Space Weather Analysis
The aurora can be used as a direct way to observe particles precipitating into the ionosphere.
The main drivers behind this particle precipitation are geomagnetic substorms which can be divided into their three phases growth, expansion and recovery.
Energy is stored by coupling between the solar wind, interplanetary magnetic field and magnetosphere.
This energy is subsequently released in the Dungey cycle after which the magnetosphere returns to normal conditions.
Two of the easily observable differences in the aurora are their shape and latitude as well as a measurable difference in the Earth's magnetic field that occurs during a substorm.
For several decades all sky imagers have been placed in regions in Scandinavia, North America and Antarctica and have been taking images of the night sky every few seconds.
At the moment several million images are taken each year, and due to the large amount of images, only a fraction can be manually analysed.
Using transfer learning we use a classifier based on a two step process where a pretrained neural network feature extractor transforms the images in a machine-readable numerical feature vector.
These features are later used for classification but have been shown to contain essential physical information embedded in the images.
Classification and clustering allows us to analyse large datasets spanning several years in a cost- and calculation-efficient manner.
Combining images with their respective measurements of the interplanetary magnetic field, the locally measured disturbances in the Earth's magnetic field and information about substorms occuring at the time of the taken image, we show relationships between the images and measured physical quantities on a statistical level and aim to forecast future conditions.
Accessing millions of images taken in the last decade, we are able to query certain space weather conditions, opening up new possibilities for statistical analysis of auroral behaviour. | | 14:30 | Polarisation of auroral emissions: confirmations and case studies | Bosse, L et al. | Oral | | | Léo Bosse1, Gael Cessateur1, Hervé Lamy1, Jean Lilensten2, 6, Nicolas Gillet3, Colette Brogniez4, Olivier Pujol4, Sylvain Rochat2, Stéphane Curaba2, Alain Delboulbé2, Magnar G. Johnsen5 | | | [1] Institut royal d’Aeronomie Spatiale de Belgique (IASB), Belgique, [2] Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) CNRS – UGA, France [3] Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, UGE, ISTerre, 38000 Grenoble, France [4] Univ. Lille, CNRS, UMR 8518 – LOA – Laboratoire d'Optique Atmosphérique, F-59000 Lille, France [5] Tromso Geophysical Observatory, UiT - the Arctic University of Norway, Tromso, Norway [6] Honorary astronomer at Royal Observatory of Belgium, Brussels | | | Study of auroral light polarisation has faced the issue of anthropic light pollution and scattering in the lower atmosphere (Bosse et al. 2020). To overcome this challenge, a polarised radiative transfer model (POMEROL) has been developed to compute the polarisation measured by a virtual instrument in a given nocturnal environment. This single-scattering model recreates real-world conditions (among them atmospheric and aerosol profiles, light sources with complex geometries at the ground and in the sky, terrain obstructions). It has been successfully tested at mid-latitudes where sky emissions are of weak intensity. We present a series of comparisons between POMEROL predictions and polarisation measurements during two field campaigns in the auroral zone, in both quiet and active conditions. These comparisons show that three main upper atmosphere emissions must be polarised: the green atomic oxygen line at 557.7 nm and the 1st N2+ negative band at 391.4 nm (purple) and 427.8 nm (blue) (Bosse et al. 2022). This polarisation can be either created directly at the radiative de-excitation or may occur when the non-polarised emission crosses the ionospheric currents.
The ionospheric origin of the polarisation being now demonstrated, we will present and discuss some of the most interesting behaviors seen in the polarisation data, during bright auroral arc events and pulsating auroras.
We discuss some of the potentialities these observations and models offer in the frame of space weather, aerosol and light pollution study. | | 14:45 | Interhemispheric investigation of variability of ionospheric parameters measured by the Swarm satellites for quiet geomagnetic conditions | Kotova, D et al. | Oral | | | Daria Kotova[1],Yaqi Jin[1],Wojciech Miloch[1] | | | Department of Physics, University of Oslo, Oslo, Norway | | | The use of satellite data allows us to study the variability of ionospheric plasma parameters globally without references to ground stations or receivers in different regions of the Earth. The Swarm mission, which was launched in November 2013 and is still operational, allows us to investigate the effects of decreasing solar activity on ionospheric variability. We use the Swarm in-situ measurements of the electron density and derived parameters that have been combined into a unique dataset called the Ionospheric Plasma IRregularities product (IPIR) [1]. IPIR provides characteristics of the plasma variability along the orbit and gives information on plasma density structures in the ionosphere in terms of their amplitudes, gradients and spatial scales. In this study, we focused on distributions and statistics of these parameters in the Northern and Southern hemispheres for quiet geomagnetic conditions. Our results provide information on the shape of the distribution and probability density functions of electron density and derived ionospheric parameters that can be used as a baseline important for other modeling studies. Understanding the distribution of such parameters in the context of the geomagnetic activity and selected ionospheric regions can have implications for the development of new satellite instruments and for the accuracy of GNSS precise positioning.
This work was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (ERC Consolidator Grant agreement No. 866357, POLAR-4DSpace).
References
[1] Y. Jin, D. Kotova, Ch. Xiong, S. M. Brask, L.B.N. Clausen, G. Kervalishvili, C. Stolle, W.J. Miloch, Ionospheric Plasma IRregularities - IPIR - data product based on data from the Swarm satellites, J. Geophys. Res. 127, e2021JA030183, https://doi.org/10.1029/2021JA030183 (2022).
| | 15:00 | Atmospheric drag effects on modelled low Earth orbit (LEO) satellites during the July 2000 Bastille Day event in contrast to an interval of geomagnetically quiet conditions | Nwankwo, V et al. | Oral | | | Victor U. J. Nwankwo[1], William Denig[2], Sandip K. Chakrabarti[3], Muyiwa P. Ajakaiye[1], Johnson Fatokun[1], Adeniyi W. Akanni[1], Jean-Pierre Raulin[4], Emilia Correia[4,5], John E. Enoh[6], and Paul I. Anekwe[1] | | | [1]Space, Atmospheric Physics and Radio Waves Propagation Laboratory, Anchor University, Lagos 100278, Nigeria; [2]Department of Sciences, St. Joseph's College of Maine, Standish, ME 04084, USA; [3]Indian Centre for Space Physics, Kolkata 700084, India; [4]Centro de Rádio Astronomia e Astrofísica Mackenzie, Universidade Presbiteriana Mackenzie, São Paulo, Brazil; [5]Instituto Nacional de Pesquisas Espaciais, INPE, São José dos Campos, São Paulo, Brazil; [6]System Engineering and Integration Unit, Interorbital systems, Mojave, CA 93502-0662, USA | | | In this work, we simulated the atmospheric drag effect on two model SmallSats (small satellites) in low Earth orbit (LEO) with different ballistic coefficients during 1-month intervals of solar–geomagnetic quiet and perturbed conditions. The goal of this effort was to quantify how solar–geomagnetic activity influences atmospheric drag and perturbs satellite orbits, with particular emphasis on the Bastille Day event. Atmospheric drag compromises satellite operations due to increased ephemeris errors, attitude positional uncertainties and premature satellite re-entry. During a 1-month interval of generally quiescent solar–geomagnetic activity (July 2006), the decay in altitude (h) was a modest 0.53 km (0.66 km) for the satellite with the smaller (larger) ballistic coefficient of 2.2×10$^{−3}$ m$^2$ kg$^{−1} (3.03×10$^{−3}$ m$^2$ kg$^{−1}). The associated orbital decay rates (ODRs) during this quiet interval ranged from 13 to 23 m per day (from 16 to 29 m per day). For the disturbed interval of July 2000 the significantly increased altitude loss and range of ODRs were 2.77 km (3.09 km) and 65 to 120 m per day (78 to 142 m per day), respectively. Within the two periods, more detailed analyses over 12 d intervals of extremely quiet and disturbed conditions revealed respective orbital decays of 0.16 km (0.20 km) and 1.14 km (1.27 km) for the satellite with the smaller (larger) ballistic coefficient. In essence, the model results show that there was a 6- to 7-fold increase in the deleterious impacts of satellite drag between the quiet and disturbed periods. We also estimated the enhanced atmospheric drag effect on the satellites' parameters caused by the July 2000 Bastille Day event (in contrast to the interval of geomagnetically quiet conditions). The additional percentage increase, due to the Bastille Day event, to the monthly mean values of h and ODR are 34.69 % and 50.13 % for Sat-A and 36.45 % and 68.95 % for Sat-B. These simulations confirmed (i) the dependence of atmospheric drag force on a satellite's ballistic coefficient, and (ii) that increased solar–geomagnetic activity substantially raises the degrading effect of satellite drag. In addition, the results indicate that the impact of short-duration geomagnetic transients (such as the Bastille Day storm) can have a further deleterious effect on normal satellite operations. | | 15:15 | Statistical Properties of 102 SPA Events | Keiling, A et al. | Oral | | | Andreas Keiling [1] | | | [1] Space Sciences Laboratory, UC Berkeley, California, USA | | | The magnetosphere tends to show certain, repeatable behaviors, called magnetospheric response modes. These modes are of great importance, because they represent manifestations of large energy transport and conversion in the global magnetospheric-ionospheric system. While the sawtooth mode, which is a ~3-hr periodic mode, has been investigated extensively, here we provide first statistics on a ~1-periodic response mode, called short-period activation (SPA) mode. We identified 102 events in the Time History of Events and Macroscale Interactions During Substorms (THEMIS) database. The magnetic dipolarization signature at 10–12 RE in the magnetotail was the defining criterium to identify events in our study. This selection includes proper substorms, pseudobreakups, and substorm intensifications/activations. In addition to dipolarization, the events show particle injections and fast plasma flows. The statistical properties of these events were compared with published results of other magnetospheric response modes to provide context. Distributions of associated Kp and solar wind speed are similar to those of substorms and very different from those of sawtooth events. It is also found that they are not associated with storms, which again is in contrast to the storm-related sawtooth mode. However, they can occur during a broad range of AE values, which suggests that the aurora can range from weak to intense. Lastly, it is worth noting that the SPA mode is more probable to occur than the sawtooth mode. These properties suggest that the SPA mode plays an important part in magnetosphere-ionosphere coupling, and due to its periodic behavior, it constitutes a significant energy flow towards the ionosphere. |
Posters| 1 | A study of spatio-temporal variability of equatorial electrojet using long-term ground-observations | Cherkos, A et al. | Poster | | | Alemayehu Mengesha Cherkos and MelesewNigussie | | | [1]Addis Ababa University, Institute of Geophysics Space Science and Astronomy, CNCS, Department of Physics, P. O. Box 1176, Addis Ababa, Ethiopia; [2]Washera Geospace and Radar science Research Laboratory, Department of Physics, Bahir Dar University, P.O. Box 79, Bahir Dar, Ethiopia | | | It is widely accepted that a quiet time equatorial electrojet (EEJ) varies daily, monthly, seasonally, and longitudinally; however, detailed characterization of these variations has not yet been done using multiple ground based stations. Therefore, the purpose of this article is to give a reasonably comprehensive comparison of day-to-day, monthly, seasonal, and longitudinal variabilities of the EEJ and its reversal counter electrojet (CEJ) occurrence during the period from 2011 to 2013. The analysis is based on a 1-minute ground-based magnetic data recorded at eight dip equatorial stations. The results obtained in this study indicate that the mean day-side EEJ is strongest around equinoxes months in the Peruvian, Southeast Asia and Philippine regions throughout the years investigated. On the other hand, stations in the African and Indian regions show medium peaks in the equinoxes months of the years 2011–2012. The EEJ strength in the Pacific sector is weakest throughout the years. The observed seasonal behavior of the peak EEJ during equinox is observed at 10:30–12:00 LT for Peruvian, Southeast Asian, and Philippine regions, but in the West African and Indian sectors, the medium EEJ peaks were observed about 1 h earlier. We also found that, on average, morning CEJ events occur more frequently than in the evening CEJ at TTB followed by AAE and HUA. The largest morning CEJ fluctuations were observed for the TTB during the whole months of the years considered in this study except the December months of 2012. During the December solstice months of 2011, the EEJ current in TTB is maximum while the medium peak has been shown in 2012 and 2013. Overall the observed average EEJ strength is maximum during equinoxes and minimum in solstices months as well as seasons. Our results also show that the magnitude of EEJ gradually increases in the Peruvian and Southeast Asian sectors while the rate of MCEJ occurrence increases at Brazilian and African regions from the years 2011 to 2013. It is also observed that the magnitude of EEJ is highering during the years of the increasing solar cycle. | | 2 | PITHIA-NRF offer access to European upper atmosphere research facilities | Häggström, I et al. | Poster | | | Ingemar Häggström | | | EISCAT Scientific Association | | | One of the objectives of the PITHIA-NRF project is to provide effective and convenient access to the best European research facilities for observations of the upper atmosphere, including the plasmasphere, ionosphere and thermosphere. The access is organised through the Trans-National Access (TNA) programme, and provides an opportunity for researcher and other users to execute and carry out their own projects at one of the twelve PITHIA-NRF research facilities. Through these activities new users will learn how to work with the facilities during the full access cycle, from setting up a campaign, to collection, analysis and finally exploitation of data with the help of tools and services provided by PITHIA-NRF.
The PITHIA-NRF nodes provide access to key experimental and data processing facilities for studies and modelling of physical processes acting in the Earth’s plasmasphere, ionosphere and thermosphere. The facilities connected to the nodes are geographically distributed over Europe, as well as internationally, and their expertise and dedication span over a wide range of topics within the research area. This variety of expertise and techniques, all with the purpose to study specific parts of the ionosphere-thermosphere-plasmasphere (ITP), allows for a common ground and a platform for a better understanding of the many different complex couplings and interactions within ITP as well as between ITP and the magnetospheric/space environment.
Users can request either physical access (one-week visit at the node with support at site) or remote access (one month access from distance with weekly support). Users with granted projects will learn how to work with the facilities during the full access cycle, from setting up a campaign, to collection, analysis and finally exploitation of data with the help of tools and services provided by PITHIA-NRF via the e-science center. For virtual access - typically referring to access to data and digital tools - there are no restrictions to the number of simultaneous users, and no selective process is needed. Access can be requested by scientific users from academia, Small and Medium Enterprises, large companies and public organizations by propose a scientific project. | | 3 | Storm-time mesoscale field-aligned currents and interplanetary parameters | Adero, A et al. | Poster | | | A. Adero Ochieng a,b, Geeta Vichare b,*, Paul Baki a, Pierre Cilliers c, Pieter Kotze c, Chao Xiong d, Ashwini Kumar Sinha | | | [a,b] Department of Physics and Space Science, Technical University of Kenya, P.O Box 52428-00200, Nairobi, Kenya [b] Indian Institute of Geomagnetism, New Panvel, Navi Mumbai, 410 218, India , [c] South Africa National Space Agency, SANSA Space Center, P.O Box 32, 7200 Hospital Street, Hermanus, South Africa , [d] GFZ German Research Centre for Geosciences, Telegrafenberg, 14473, Potsdam, Germany | | | Present paper studies Field aligned currents (FACs) estimated by employing Ampere’s law to the magnetic field recorded by CHAMP satellite during 24 geomagnetic storms. Low-pass filtered FACs with a cutoff period of 20 s (scale size~150 km) are used to determine FAC range, which is defined as a peak-to-peak amplitude of FAC density. Thus we are considering only the strongest positive and negative FACs emerging either from Region 1, Region 2, Region 0, or substorm current wedge systems. It is known that the FACs significantly depend on the highly variable solar wind (SW) and interplanetary magnetic field (IMF) conditions and also on the processes internal to magnetospheric-ionospheric system such as substorm. The correlation analysis carried out here shows that sometimes the FAC range, correlates well with SymH, AsyH, AsyD, AL, am and Kp indices (>95% significance), but not always. The variation of the FAC range with magnetic local times shows distinctly different patterns during southward and northward IMF conditions, with peaks near dawn-dusk during southward IMF and near local noon-midnight during northward IMF. These results are in agreement with the earlier reports.
However, the seasonal dependence reveals that the noon time peak is essentially associated with the summer season. We have determined a new parameter called ‘occurrence rate of FAC range <1 μA/m2’ and examined it under various solar wind and IMF conditions. It is found that the probability of FAC range <1 μA/m2 have a clear dependence on the clock angle, suggesting more frequent intensifications during southward IMF. Clear linear
dependence on the cone angle demonstrates higher occurrence probability of FAC range < 1 μA/m2 when the IMF is perpendicular to the Sun-Earth line (cone angle nearing 90 deg). All these results based on the newly defined parameters such as FAC range and probability of FAC range <1 μA/m2, for the storm time mesoscale FAC are consistent with the previous studies. The FAC ranges are found to have a linear dependence on the values of IMF
BY, BYZ, BT and BZ, though saturation is apparent at higher values of the IMF parameters. FAC range shows distinctly different dependence for slow and fast solar wind, suggesting the importance of the composition and properties of SW in controlling the FAC strengths. | | 4 | GIM-TEC forecast for the past and future during spotless days | Haralambous, H et al. | Poster | | | Tamara Gulyaeva[1] and Haris Haralambous[2] | | | [1]IZMIRAN, Troitsk, 108840 Moscow, Russia; [2]Frederick Research Center, Nicosia, Cyprus | | | We presents scenario for GIM-TEC forecasting for the past and future derived from variability indices of the Earth’s ionosphere and magnetic field under imperceptible solar activity during spotless Sun. The statistics of spotless days observed on the Sun in transiting through the solar cycle minimum is presented at Solar Influences Data Analysis Center (https://wwwbis.sidc.be/silso/).
The analysis of the geomagnetic Kp-index disturbances (Kp > 3) and global 3-h ionospheric indices WU (positive TEC enhancement), WL (negative diminution) and their range WE [1] is made for the spotless days during 23rd-25th Solar Cycles (SC). Relevant WU, WL and WE indices are observed from the daily-hourly global W-index maps based on JPL GIM-TEC maps. We present algorithm for the past and forward modelling of GIM-W maps and GIM-TEC maps using the persistent relationships of daily variation of peak WU, WL and WE indices with peak Kp index during spotless days.
The training database includes 665 days with Kp > 3 from the total 1282 spotless days from 1996 to 2021 when majority of spotless days occurred for 400 years of SSN observations. The training set presents a fraction of 22% from the total 3082 spotless days with Kp > 3 observed from 1950 to 2022. Space weather storm observed for the spotless Sun is demonstrated on 6-8 November 2017. The proposed scenario for 3-h WU, WL and WE forecasting is applied to selected spotless days with Kp > 3 occurred from 1950 to 1993 producing GIM-W maps and GIM-TEC before the epoch of GNSS observation.
This study is supported by RFBR 19-52-25001_Kipr_a, Russia, and RPF Bilateral/Russia(RFBR)/1118/0004 (RENAM), Cyprus.
[1] Gulyaeva, T.L., Haralambous, H. Three-hourly indices of ionospheric activity. Geomagn. Aeronomy, 61(6), 836-845, 2021. DOI: 10.1134/S0016793221060062.
| | 5 | Ionospheric irregularities embedded in a Plasma Bubble as probed with a Swarm overfly | Spogli, L et al. | Poster | | | Luca Spogli [1][2], Lucilla Alfonsi[1] and Claudio Cesaroni[1] | | | [1]Istituto Nazionale di Geofisica e Vulcanologia, [2]SpacEarth Technology | | | Small scale irregularities embedded in the post-sunset equatorial plasma bubbles (EPB) are the principal source of GNSS signal degradation triggered by ionospheric scintillation. Small scale irregularities form in the plasma cascading processes from large-ones along the magnetic field that characterize the EPB evolution. The 3 satellites (Swarm A, Swarm B and Swarm C) constituting the ESA’s Swarm satellite mission follow a quasi-Sun-synchronous near-polar orbit. The orbital altitudes of the closely-separated Swarm A and C satellites are about 460 km (with separation by 1.4° in longitude, 155 km at the equator), the orbit of Swarm B is at an altitude of about 510 km. The different orbital inclination of the satellites results in different drift rates in local time (LT). On 30 September 2021, a rare overfly of the three satellites occurred in the South American sector, with a minimum zonal separation between Swarm A and Swarm B of 118 km at 00:50:14 UT. The local time and ionospheric conditions were such that the overfly occurred exactly in a post-sunset equatorial plasma bubble and gave the precious occasion to study it at different altitudes with in-situ data at almost the same longitudinal sector. The Swarm-based analysis is conducted by leveraging on the parameters derived from the in-situ plasma measurements and from the topside ionosphere total electron content, embedded in the Ionospheric Plasma IRregularities (IPIR) data product, which is able to provide a comprehensive dataset for characterizing plasma structuring along the orbits of the Swarm satellites.
The features of the plasma bubble are also reconstructed by leveraging on a dense network of GNSS receivers, form which the total electron content, its spatial gradients (N-S and E-W), the rate of TEC change index (ROTI) and the amplitude scintillation index are derived. The rare overfly allows to reconstruct how the elongation of the plasma of the bubble over the magnetic field lines results in plasma cascading from large to small scale, resulting in different patterns of S4 and ROTI enhancements.
| | 6 | ATISE : Ground campaigns and calibrations | Mathieu, B et al. | Poster | | | Mathieu Barthelemy[1,3], Juliette Robuschi[1], Elisa Robert[1,2], Laura Serra Amengual[1] | | | [1]Univ. Grenoble Alpes, CSUG, F38000 Grenoble, France; [2]SpaceAble; [3]Univ. Grenoble Alpes, CNRS, IPAG, F38000 Grenoble, France | | | The ATISE instrument is a Fizeau like spectrometer dedicated to the observation of the aurora from space on board a 12U cubesat. The planed orbit is a SSO which allows more than 15 observations per day of each oval. It aims to sight at the limb to observe the vertical profile of the auroras. The specificity of this spectrometer is to be very sensitive and thus to allow spectral reconstruction with 1s exposure time on a FoV of 1.5°x1°. The spectral resolution is around 1 nm between 380 and 900 nm.
Once operational, this instrument will be extremely useful for auroral monitoring from both the ground and space. However, in Fourier transform spectroscopy, the reconstruction of the intensity of each line is really challenging especially when SNR is low.
In this work, we propose to describe the data processing pipe of this instrument, to describe the tests and field campaigns realized and then to characterize the performances of the instrument on the ground. Simulations for the future space instrument will be described and conclusions for future campaigns and space instrument will be given.
| | 8 | Modeling of TEC irregularities over Greenland based on empirical orthogonal function method | Jin, Y et al. | Poster | | | Yaqi Jin[1], Lasse B.N. Clausen[1], Wojciech J. Miloch[1], and Per Høeg[1] | | | Department of Physics, University of Oslo, PO Box 1048, Blindern, 0316 Oslo, Norway | | | In this study, we develop a climatological model based on the long-term climatology (over two solar cycles) of total electron content (TEC) irregularities from a polar cap station (Thule) using the rate of change of the TEC index (ROTI). As the first step, we construct the long-term climatology that reveals variabilities over different time scales, i.e., solar cycle, seasonal, and diurnal variations. Different drivers/contributors can explain these variations in different time scales. Among the drivers, the solar radiation index F10.7P characterizes the longest time scale variations over solar cycle. The seasonal variations can be explained by the interplay of the energy input into the polar cap ionosphere and the solar illumination that damps the amplitude of ionospheric irregularities. The diurnal variations are due to the relative motiomn of the station with respect to the auroral oval. In order to develop a climatological model, we decompose the climatology of ionospheric irregularities using the empirical orthogonal function (EOF) method. Due to the rapid convergence of the EOF method, the first four EOFs could reflect the majority (99.49%) of the total data variability. In order to build an empirical model, we fit the EOF coefficients using three geophysical proxies (namely, F10.7P, Bt, and Dst) based on the correlation analysis. The data-model comparison shows satisfactory results with a high Pearson correlation coefficient and adequate errors. Since the empirical model is only dependent on F10.7P, Bt, and Dst, we are able to model the historical ROTI during the modern grand maximum dating back to 1965 and made the prediction during solar cycle 25 using historical and prediction of geophysical proxies. For the first time, we can directly study the climatic variations of the ROTI activity across six solar cycles. | | 9 | First 3D results with Vlasiator on auroral proton precipitation during southward interplanetary magnetic field driving | Grandin, M et al. | Poster | | | Maxime Grandin[1], Thijs Luttikhuis[1], Markku Alho[1], Markus Battarbee[1], Harriet George[1], Lucile Turc[1], Maxime Dubart[1], Yann Pfau-Kempf[1], Urs Ganse[1], Maarja Bussov[1], Giulia Cozzani[1], Evgeny Gordeev[1], Konstantinos Horaites[1], Konstantinos Papadakis[1], Jonas Suni[1], Vertti Tarvus[1], Fasil Tesema[1], Ivan Zaitsev[1], Hongyang Zhou[1], Minna Palmroth[1,2] | | | [1]Department of Physics, University of Helsinki, Helsinki, Finland; [2]Space and Earth Observation Centre, Finnish Meteorological Institute, Helsinki, Finland | | | The precipitation of charged particles from the magnetosphere into the ionosphere is one of the crucial coupling mechanisms between these two regions of geospace and is associated with multiple space weather effects, such as global navigation satellite system signal disruption and geomagnetically induced currents at ground level. While precipitating particle fluxes have been measured by numerous spacecraft missions over the past decades, it often remains difficult to obtain global precipitation patterns with a good time resolution during a substorm. Numerical simulations can contribute to bridge this gap and help improve the understanding of mechanisms leading to particle precipitation at high latitudes through the global view they offer on the near-Earth space system. We present the first results on auroral (0.5–50 keV) proton precipitation within a 3-dimensional simulation of the Vlasiator hybrid-Vlasov model. The run is driven by southward interplanetary magnetic field conditions with steady solar wind parameters. We find that, on the dayside, cusp proton precipitation exhibits the expected energy–latitude dispersion and takes place in the form of successive bursts associated with the transit of flux transfer events formed through dayside magnetopause reconnection. On the nightside, the precipitation patterns follow the typical auroral substorm development, but it appears clearly that the precipitating particle injection is taking place within a narrow magnetic local time span. Finally, the simulated precipitating fluxes are compared to observations from the Defense Meteorological Satellite Program spacecraft during similar driving conditions and are found to be in good agreement with the measurements. | | 10 | Distributed Space weather Sensor System observations of the magnetosphere, ionosphere and thermosphere | Heil, M et al. | Poster | | | Melanie Heil, Stefan Kraft, Juha-Pekka Luntama, Alexi Glover | | | European Space Agency | | | Monitoring of the Earth's and Sun's environment is an essential task for the now- and forecasting of Space Weather and the modelling of interactions between the Sun and the Earth. Due to the asymmetry and complexity of Earth's magnetosphere, ionosphere and thermosphere it is necessary to capture the state of the magnetic field, and the particle and plasma distribution in a sufficiently large number of sampling points around the Earth, such that it allows state-monitoring and modelling of the involved processes with sufficient accuracy and timeliness.
ESA is implementing the Distributed Space Weather Sensor System (D3S) to observe the effects of solar activity within Earth's vicinity, addressing the data gap in close to real-time observations of the magnetosphere, ionosphere and thermosphere system. First measurements are available from hosted payloads with more becoming available over the next years. In addition multiple dedicated mission concepts are currently under study. The status and plans for D3S monitoring will be presented. | | 11 | Signal arriving direction monitoring tool for PL610 LOFAR station | Pozoga, M et al. | Poster | | | Mariusz Pozoga[1],Helena Ciechowska[1],Barbara Matyjasiak[1],Hanna Rothkaehl[1] | | | [1]Space Research Centre, Polish Academy of Sciences | | | A single LOFAR station allows the reception of anthropogenic radio signals reflected from the ionosphere. The ability to track the direction of signal arrival makes it possible to detect moving structures in the ionosphere, such as TIDs, atmospheric gravity waves, and other phenomena that cause changes in the propagation of signals.
In this work we present a test system that allows tracking the signal direction of arrival and its changes in time scales from a fraction of a second to several hours, enabling tracking of a wide range of various phenomena.
For this purpose, the signal is received by 4 antennas in the frequency range of 8-18 MHz. It allows precise determination of the reception direction. The signals used to track changes are searched automatically and the direction of the signal is recorded for later analysis.
In this research, we present the results of test measurements carried out with the use of the PL610 station. | | 12 | Detection of Travelling Ionospheric Disturbances and effects in the HF direction finding system | Segarra, A et al. | Poster | | | Antoni Segarra[1], David Altadill[1], Jens Tölle[2], Stefan Unger[2] | | | [1]Observatori de l’Ebre (OE), CSIC - Universitat Ramon Llull, Roquetes, Spain; [2]German Federal Police, Swisttal-Heimerzheim„ Germany | | | Travelling Ionospheric Disturbances (TIDs) are plasma density fluctuations that propagate as waves through the ionosphere at a wide range of velocities and frequencies. HF-Int method was developed in the framework of the TechTIDE project to detect and to monitor TIDs in near real time. Further validation of the goodness of the HF-Int method is done by the analysis of its response to the detection of TID launched as effects of corotating Coronal Hole High Speed Stream, that caused Large Scale TIDs during several solar rotations from July to November 2021. In this work we also analyze the potential impact of the TIDs on the HF Direction Finding (DF) measurements developed by the German Federal Police (GFP). GFP measurements of azimuths recorded by HF-DF for given HF beacons are compared with LSTID activity detected by the HF-Int method. The results indicate that the angle between the direction of propagations of the LSTID and the azimuth direction from the HF transmitter beacons to the HF-DF receiver have an influence on the degradation in the HF-DF measurements. The HF-Int method is a candidate to be included as a new TechTIDE product in the ESA portal through the SWESNET contract. | | 13 | The Time-Frequency Analysis (TFA) toolbox: a versatile processing tool for the recognition of geophysical signals in Swarm time series | Balasis, G et al. | Poster | | | Georgios Balasis[1], Constantinos Papadimitriou[1], Adamantia Zoe Boutsi[1], Georgios Vasalos[1], Omiros Giannakis[1], Alexandra Antonopoulou[1], Ashley Smith[2], Klaus Nielsen[3] | | | [1]IAASARS, National Observatory of Athens, Greece, [2]School of GeoSciences, University of Edinburgh, UK, [3]DTU Space, Denmark | | | The ongoing Swarm mission of the European Space Agency (ESA) provides an opportunity for a better knowledge of the near-Earth electromagnetic environment, including investigations of ultra-low frequency (ULF) wave events. The Time-Frequency Analysis (TFA) tool is a processing tool established for deriving Pc1 (0.2–5 Hz) and Pc3 (20–100 mHz) wave indices. The tool includes both a graphical interface as well as a dedicated back-end that can be used to perform wavelet analysis and visualize the results for both Pc1 and Pc3 waves, using both Swarm magnetic Level 1b 50 Hz and 1 Hz data. Following recommendations from the Advisory Board of the Swarm Data, Innovation and Science Cluster (Swarm DISC) the tool has been further developed and generalized so as to accommodate analysis of other types of time series from both satellite and ground station measurements. In particular, the resulting TFA toolbox provides users with the capabilities of studying different wave types (e.g. compressional waves, Alfven waves, etc.), various magnetic field components (e.g. in Mean Field Aligned – MFA coordinates), and other geophysical measurements (e.g. electric field, plasma parameters). The TFA toolbox is also able to detect geophysical signals, e.g. due to plasma instabilities, and artificial disturbances (anomalies), e.g. spikes, jumps. It is possible also to use data from ground stations in a consistent format, e.g. 1 Hz magnetic observatory data as available in the virtual research service - VirES for Swarm. Moreover, integration of the TFA toolbox into the VirES platform is currently under development. This presentation aims to demonstrate the unique capabilities of the Swarm DISC TFA toolbox. | | 14 | Observations of stable auroral arcs with the ALIS network leading to the precipitating electron flux | Cessateur, G et al. | Poster | | | Gaël Cessateur[1], Hervé Lamy[1], Marius Echim[1], Cyril Simon Wedlund[2], Guillaume Gronoff[3,4], Romain Maggiolo[1] | | | [1]Belgian Institute for Space Aeronomy, Brussels, Belgium, [2] Space Research Institute, Austrian Academy of Sciences, Graz, Austria, [3]NASA, LaaRC, Hampton Va, USA,[4] SSAI, Hampton Va, USA | | | We present a set of inversion and optimization methods for estimating the precipitating electron flux from multi-stations ground-based optical observations of a stable auroral arc obtained with the ALIS (Auroral Large Imaging System) network in 2008 in Northern Scandinavia.
First, the three-dimensional (3D) volume emission rate (VER) of the N2+ blue band at 427.8 nm is retrieved using a tomography-like technique using the optical images obtained simultaneously with the ALIS cameras. Since the excitation of this emission band is solely due to impact with precipitating magnetospheric electrons, a linear forward model can be used to relate the flux of magnetospheric precipitating electrons and the profile of the blue emission along each local magnetic field line. The second step of the method consists in inverting the forward model along each magnetic field line across the reconstructed 3D VER of the blue emission to obtain the 2D distribution in latitude/longitude of precipitating electrons as a function of their energy.
Following C. Simon Wedlund et al. (2013), those two consecutive inversions are applied to auroral arcs observed with ALIS on March 7th 2008. Data from the nearby EISCAT radar are used to validate the results of the inversion of ALIS data along one particular magnetic field line. The VER of the green line of atomic oxygen (557.7nm) and of the blue line is compared with the 1-D kinetic electron transport model Aeroplanets.
| | 16 | SUBSTORM MAGNETIC EFFECTS AT MID-LATITUDES AND LARGE-SCALE STREAMS IN THE SOLAR WIND | Despirak, I et al. | Poster | | | Irina Despirak[1], Andris Lubchich[1], Nataliya Kleimenova[2], Suvorova Z.V.[1] | | | [1] Polar Geophysical Institute, Apatity. Russia, [2] Schmidt Institute of the Physics of the Earth RAS, Moscow, Russia | | | Our study is devoted to the investigations of mid-latitude geomagnetic effects of magnetospheric substorms as one of important elements of the space weather. We considered mid-latitude magnetic effects of some types of substorms depending on different large-scale solar wind streams. The OMNI data base and the catalog of the large-scale solar wind phenomena (ftp://ftp.iki.rssi.ru/omni/) have been used to determine the type of the solar wind stream. Six solar wind stream types have been analyzed: the high speed streams from coronal holes (HSS); the interplanetary manifestations of coronal mass ejections: the magnetic clouds (MC) or EJECTA; the regions of compressed plasma before these streams – CIR and SHEATH; the slow solar wind (SLOW) streams. The substorm selection was based on the data from SuperMAG global magnetometers network and meridional chain of IMAGE magnetometers. The appearance of positive bays as the mid-latitude effect of auroral substorms were controlled by magnetic data from the mid-latitude European stations BEL, PAG, SUA, BOX et al. Mid-latitude effects of two special types of substorms have been compared: (1) of very intense substorms called supersubstorms- SSS (with SML index < - 2500 nT) and (2) of weak high-latitude substorms observed at the geomagnetic latitudes higher ~ 70° MLAT (“polar” substorms). It was shown that supersubstorm events were associated with CME manifestations- SHEATH, MC, EJECTA- and they almost did not observe during HSS or SLOW. The "polar" substorms were observed during SLOW and EJECTA that occur against the background of a slow flow of solar wind, as well as at the end or at the beginning of FAST, when the solar wind speed already or not yet reaches high values. It was found that the SSS and polar substorms as the “classical” ones are typically accompanied by the mid-latitude positive magnetic bays being an indicator of Substorm Current Wedge.
The reported study was funded by RFBR and NSFB, project number 20-55-18003.
| | 17 | Thermospheric conditions associated with the loss of 40 Starlink satellites | Zhang, Y et al. | Poster | | | Yongliang Zhang[1], Larry J. Paxton[1], Robert Schaefer[1], and William H. Swartz[1] | | | [1] The Johns Hopkins University Applied Physics Laboratory | | | We analyzed FUV data from DMSP/SSUSI and TIMED/GUVI and found significant changes in the thermospheric density and composition during the February 3-5, 2022 storm when 40 Starlink satellites started to re-enter the atmosphere associated with increased neutral drag at an altitude around 210 km. TIMED/GUVI observations showed a clear increase in the thermospheric N2/O column density ratio and an increase in the nitric oxide (NO) column density, indicating a high thermospheric density and temperature. DMSP SSUSI 130.4 nm limb data showed a clear increase in neutral density in the low latitude region (-30° to 30°). On the duskside (17:32 LT), the density increase (compared to the pre-storm density) is around 11-18% at 210 km and around 18-26% at 520 km. On the dawnside (05:19 LT), the density increase is more significant, 40-59% at 210 km and ~300% at 520 km. There are a few reasons for the dawn-dusk asymmetry in the relative density increase: (1) the pre-storm background density or heat capacity is lower on the dawnside than that on the duskside, (2) stronger auroral heating was observed on the dawnside based on analysis of auroral images, (3) the thermosphere density enhancement partially recovered when the disturbance co-rotated with the Earth from dawn to dusk side due to enhanced IR cooling by NO. Note it is difficult to do in situ measurements around 200 km altitude. Space based FUV imagers can provide real time monitoring of themrospheric conditions at different altitude for safe LEO satellite operation. | | 18 | Forecasting the high-latitude ionospheric electric field using the BAS reanalysis of Super Dual Auroral Radar Network (SuperDARN) data | Lam, M et al. | Poster | | | Mai Mai Lam[1], Robert M. Shore[1], Gareth Chisham[1], Mervyn P. Freeman[1], Adrian Grocott[2], Maria T. Walach[2], Lauren Orr[2] | | | [1]British Antarctic Survey (BAS), Cambridge, UK; [2]Lancaster University, Physics Department, Lancaster, UK | | | Forecasting of the effects of thermospheric drag on satellites will be improved significantly with more accurate modelling of space weather effects on the high-latitude ionosphere, in particular Joule heating from electric field variability. This is the largest uncertainty in orbit prediction for satellites and space debris. We use a regression analysis to build a forecast model of the ionospheric plasma ExB drift velocity which is driven by relatively few solar and solar wind variables. The model is developed using a solar cycle’s worth (1997 to 2008 inclusive) of 5-minute resolution reanalysis dataa developed from Super Dual Auroral Radar Network (SuperDARN) observations along the line-of-sight of the ExB drift velocity in the high-latitude northern hemisphere. At key stages of development of the forecast model, we use the Priestley skill score to see how well the model reproduces the reanalysis dataset. The final forecast model is driven by four variables: 1. the interplanetary magnetic field component By, 2. the solar wind coupling parameter epsilon, 3. a trigonometric function of day of year, and 4. the monthly f10.7 index. The forecast model is skilled at reproducing the reanalysis plasma velocities, with a characteristic skill score of 0.69. The forecast and reanalysis data compare well around the solar maximum of 2001. The forecast skill is lower around solar minimum, due to occasional limitations in the geographical and temporal coverage of the SuperDARN instrumentation. In addition, this may also indicate the need to modify our model of driving processes around the minimum of the solar cycle.
a. Shore, R. M., Freeman, M. P., & Chisham, G. (2021). Data-driven basis functions for SuperDARN ionospheric plasma flow characterization and prediction. Journal of Geophysical Research: Space Physics, 126, e2021JA029272. https://doi.org/10.1029/2021JA029272
| | 19 | A 3-Dimensional MHD Study of Flux Transfer Events at the Dayside Magnetopause | Paul, A et al. | Poster | | | Arghyadeep Paul[1], Bhargav Vaidya[2], Antoine Strugarek[3] | | | [1]Indian Institute Of Technology Indore; [2]Indian Institute Of Technology Indore; [3]Département d’Astrophysique/AIM, CEA/IRFU, CNRS/INSU, Université Paris-Saclay | | | Localized magnetic reconnection at the dayside magnetopause is responsible for the production of transient Flux Transfer Events (FTEs) at the boundary layer. The magnetic field topology within the FTEs is that of complex helical flux-ropes and such structures have been widely detected by in-situ observations. Leveraging the Adaptive Mesh Refinement (AMR) strategy, we perform 3-dimensional magnetohydrodynamic simulations of the magnetosphere of an Earth-like planet in order to study the evolution of these FTEs. For the first time, we detect and track multiple irregular FTE structures in 3D from our simulations using an agglomerative hierarchical clustering algorithm and present a complete statistical picture of FTE evolution from a volumetric perspective. A statistical study on the thermodynamic quantities within the FTE volumes spanning across multiple such structures confirm that continuous reconnection is the dominant cause of active FTE growth. An investigation into the magnetic properties of the FTEs show that there exists a rapid tendency of currents within the structures towards being field aligned. An assessment on the validity of the linear force-free flux rope model for such FTEs confirms that the structures drift towards a constant-alpha state but continuous reconnection inhibits the attainment of a purely linear force-free configuration. Furthermore, we provide a statistical picture of the volumetric, cross sectional and azimuthal size distribution of these FTEs in addition to quantifications on the flux estimates of these FTE structures and complement these metrics based on in-situ observations at the dayside magnetopause.
| | 20 | Comparison of the Feldstein-Starkov Auroral Oval Model with the Epsilon Parameter for Various Geomagnetic Storms | Ökten, M et al. | Poster | | | Mehmet Baran Ökten[1,2], Zehra Can[1] | | | [1]Yildiz Technical University; [2]TUBITAK MAM Polar Research Institute | | | Auroras are bright bands of light formed by the precipitation of various molecules in the atmosphere in the Earth's polar regions as a result of geomagnetic storms caused by solar activity. Auroras form around the polar cap containing highly intense magnetic field lines, almost independently of the Earth's rotation, and in a ring-shaped region known as the Auroral Oval. The Auroral Oval shifts with the weather, spreading to higher latitudes during periods of strong solar activity and vice versa. Auroral electrojets can be seen as a projection of the magnetosphere in the earth's atmosphere, as they can be caused by various factors, and are critical for space weather studies, particularly for a better understanding of the magnetosphere-ionosphere coupling. In this study, the dependence of the Feldstein-Starkov Oval model, which is a function of the AL Auroral Electrojet index, which is used to determine the boundaries of the Auroral Oval, to parameters such as the velocity, magnetic field, and number density of the solar wind measured by the WIND spacecraft was investigated and compared with the Akasofu Epsilon Parameter, which is the energy input denotes the amount of energy transported from the Sun to the magnetosphere via the solar wind dedicated again with the WIND spacecraft. The findings are computed and compared with the OVATION Prime auroral precipitation model for the G3 class geomagnetic storm on 10 April 2022, the G2 class on 13 March 2022, and the G1 class geomagnetic storm on 4 February 2022. | | 21 | Medium-term predictions of F10.7 and F30 cm solar radio ux with RESONANCE | Podladchikova, T et al. | Poster | | | Tatiana Podladchikova[1], Elena Petrova[1], Astrid M. Veronig[2,3], Stijn Lemmens[4], Benjamin Bastida Virgili[5], Tim Flohrer[4] | | | [1] Skolkovo Institute of Science and Technology, [2] Institute of Physics, University of Graz, [3]Kanzelhöhe Observatory for Solar and Environmental Research, University of Graz, [4] ESA/ESOC, [5] IMS GmbH@ESA/ESOC | | | The solar radio flux at F10.7 and F30 cm is required by most models characterizing the state of the Earth's upper atmosphere, such as the thermosphere and ionosphere, to specify satellite orbits, re-entry services, collision avoidance maneuvers, and modeling of the evolution of space debris. We develop a method called RESONANCE (Radio Emissions from the Sun: ONline ANalytical Computer-aided Estimator) for the prediction of the 13-month smoothed monthly mean F10.7 and F30 indices 1–24 months ahead. The prediction algorithm has three steps. First, we apply a 13-month optimized running mean technique to effectively reduce the noise in the radio flux data. Second, we provide initial predictions of the F10.7 and F30 indices using the McNish–Lincoln method. Finally, we improve these initial predictions by developing an adaptive Kalman filter with identification of the error statistics. The rms error of predictions with lead times from 1 to 24 months is 5–27 solar flux units (sfu) for the F10.7 index and 3–16 sfu for F30, which statistically outperforms current algorithms in use. The proposed approach based on the Kalman filter is universal and can be applied to improve the initial predictions of a process under study provided by any other forecasting method. Furthermore, we present a systematic evaluation of re-entry forecast as an application to test the performance of F10.7 predictions on past ESA re-entry campaigns for payloads, rocket bodies, and space debris that re-entered from 2006 to 2019 June. The test results demonstrate that the predictions obtained by RESONANCE in general also lead to improvements in the forecasts of re-entry epochs. | | 22 | Multi-instrumental investigation of the solar flares impact on the ionosphere on 05–06 December 2006 | Barta, V et al. | Poster | | | Veronika Barta[1], Randa Natras [2], Vladimir Srećković [3], David Koronczay [4], Michael Schmidt [2], and Desanka Šulic [5] | | | [1] Institute of Earth Physics and Space Science (ELKH EPSS), Sopron, Hungary [2] Department of Geodesy and Aerospace, Deutsches Geodätisches Forschungsinstitut der Technisches Universtität München (DGFI-TUM), Technical University of Munich, Munich, Germany [3] Institute of Physics Belgrade, University of Belgrade, Belgrade, Serbia [4] Department of Geophysics and Space Science, Institute of Geography and Earth Sciences Eötvös Loránd University, Budapest, Hungary [5] Faculty of Ecology and Environmental Protection, University Union - Nikola Tesla, Belgrade, Serbia | | | The sudden increase of X-radiation and EUV emission following solar flares causes additional ionization and increased absorption of electromagnetic (EM) waves in the Earth’s atmosphere. The solar flare impact on the ionosphere above Europe on 05 and 06 December 2006 was investigated using ground-based (ionosonde and VLF) and satellite-based data (Vertical Total Electron Content (VTEC) derived from GNSS observations and VLF measurements from DEMETER satellite). Based on the Kp and Dst indices, 05 December 2006 was a quiet day, while there was a geomagnetic storm on 06 December 2006. The total fade-out of the EM waves emitted by the ionosondes was experienced at all investigated stations during an X9 class flare on 05 December 2006. The variation of the fmin parameter (first echo trace observed on ionograms, it is a rough measure of the “non-deviative” absorption) and its difference between the quiet period and during the flares have been analyzed. A latitude dependent enhancement of fmin (2–9 MHz) and Δfmin (relative change of about 150%–300%) was observed at every station at the time of the X9 (on 05 December) and M6 (on 06 December) flares. Furthermore, we analyzed VTEC changes during and after the flare events with respect to the mean VTEC values of reference quiet days. During the X9 solar flare, VTEC increased depending on the latitude (2–3 TECU and 5%–20%). On 06 December 2006, the geomagnetic storm increased ionization (5–10 TECU) representing a “positive” ionospheric storm. However, an additional peak in VTEC related to the M6 flare could not be detected. We have also observed a quantifiable change in transionospheric VLF absorption of signals from ground transmitters detected in low Earth orbit associated with the X9 and M6 flare events on 05 and 06 December in the DEMETER data. Moreover, amplitude and phase of ground-based, subionospherically propagating VLF signals were measured simultaneously during the investigated flares to analyze ionosphere reaction and to evaluate the electron density profile versus altitude. For the X9 and M6 flare events we have also calculated the ionospheric parameters (sharpness, reflection height) important for the description and modelling of this medium under forced additional ionization. | | 23 | Assessment of space weather conditions that may impact the lifetime of low altitude satellites | Baruah, Y et al. | Poster | | | Yoshita Baruah[1,2], Souvik Roy[1], Suvadip Sinha[1], Erika Palmerio[3], Sanchita Pal[4,5], Dibyendu Nandy[1,2] | | | [1]Center of Excellence in Space Sciences India, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India; [2]Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India; [3]Predictive Science Inc., San Diego, CA 92121, USA; [4]NASA GSFC, Greenbelt, MD, USA; [5]George Mason University, 4400 University Drive, Fairfax, VA, USA | | | Coronal mass ejections (CMEs) propagate through the interplanetary medium and, when Earth-directed, drive geomagnetic storms. In the event of such a storm, most of the energy that is deposited into the Earth’s atmosphere is in the form of Joule heating. This leads to an upwelling of the thermosphere which increases the drag on satellites, and can significantly impact their orbital lifetime. On 04 February 2022, 40 out of 49 satellites launched by SpaceX were de-orbited due to the impact of a geomagnetic storm. We have performed a detailed analysis of in-situ data at 1 AU to study the interplanetary structures which caused the geomagnetic perturbations and have attempted to establish their solar origin. Furthermore, we have performed magnetohydrodynamic modelling studies to establish the physics that governs these space weather impacts. In this talk I shall present the findings of our study which are relevant for protection of our space-based technological assets.
| | 24 | Instrumental issues in Spread F automatic detection from ionograms | Scotto, C et al. | Poster | | | Carlo Scotto, Alessandro Ippolito, Dario Sabbagh | | | Istituto Nazionale di Geofisica e Vulcanologia | | | A routine for automatic detection of diffused echoes known as Spread F, which appear in ionograms due to the presence of ionospheric irregularities, was developed to reject bad quality ionograms. Such a routine was also used in a retrospective analysis of large quantities of data. The results of a climatological study based on ionograms recorded at the station of Tucumán are summarized.
Furthermore we use the data of the co-located ionosondes of Rome (AIS-INGV and DPS4) to show that the observation of ionospheric irregularities on ionograms is in some extent dependent from the used instrumentation.
| | 25 | An imaging Polarimeter for the Auroral Line Emissions | Cessateur, G et al. | Poster | | | Gaël Cessateur[1], Herve Lamy[1], Leo Bosse[1], Mathieu Barthelemy[2], Jean Lilensten[2], Magnar G. Johnsen[3] | | | [1]Belgian Institute for Space Aeronomy, Brussels, Belgium; [2]Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) CNRS – UGA, France; [3]Tromso Geophysical Observatory, UiT - the Arctic University of Norway, Tromso, Norway | | | The measurements of the polarization of auroral emission lines in the Earth’s atmosphere is of particular interest for the understanding of the upper atmosphere but also for potential space weather applications. Emissions from the oxygen red line at 630 nm has been observed polarized since 2008 and the origin of the polarization is likely due to the imbalance of Zeeman sublevels, which comes from the magnetospheric electrons precipitating with a pitch angle distribution more or less aligned with the local magnetic field. The polarization of the blue line at 427.8 nm from N2+, and the green light at 557.7 nm from the atomic oxygen have been also ob-served but their origin remains unknown. Those observations were carried out using multi-wavelength sensitive photo-polarimeters with a narrow field of view, of about 2°. Here we will present a new prototype, the Polar Lights Imaging Polarimeter (PLIP), using 4 high-resolution monochrome cooled CMOS cameras with very low read-out noise, and a FOV of approximately 44° x 30°. Those cameras are designed for faint deep sky objects, and paired with some 24mm lenses opened at F/2.8. We added up some linear polarization filters oriented at 0°, 45°, 90° and 135° to infer the DoLP and AoLP. Filter wheels have been added with narrow interference filters (with a FWHM of about 3 nm) centered on the blue (427.8 nm), green (557.7 nm) and red (630.0 nm) emission lines. Some preliminary results will be presented from an observation campaign in Norway in December 2021, using a 2-cameras version of PLIP, giving access to the Q-Stokes parameter only.
| | 26 | High-latitude ionospheric electric field model comparison during the September 2017 geomagnetic storm | Orr, L et al. | Poster | | | L. Orr[1,2], A. Grocott[1], M.-T Walach[1], G. Chisham[3], M.P. Freeman[3], R.M. Shore[3], M.M. Lam[3] | | | [1] Lancaster University, Physics Department, Lancaster, [2] Now at British Geological Survey, Edinburgh, [3] British Antarctic Survey, Cambridge | | | Models of the high-latitude ionospheric electric field are commonly used to specify the magnetospheric forcing in thermosphere or whole atmosphere models. Accurate modelling is important for prediction of the thermospheric density variability affecting satellite drag. The use of decades-old models based on spacecraft data is still widespread. Currently the Heelis (Heelis et. al., 1982) and Weimer (Weimer, 2005) climatology models are most commonly used but it is possible a more recent electric field model could improve forecasting functionality. Modern electric field models, derived from radar data, have been developed to incorporate advances in data availability (Thomas & Shepherd, 2018; Walach et al., 2022; Bristow et al., 2022). It is expected that climotologies based on this larger and up-to-date dataset will better represent the high latitude ionosphere and improve forecasting abilities. An example of two such models, which have been developed using line-of-sight velocity measurements from the Super Dual Auroral Radar Network (SuperDARN) are the Thomas and Shepherd model (TS18) (Thomas & Shepherd, 2018), and the Time-Variable Ionospheric Electric Field model (TiVIE) (Walach & Grocott, 2022). Here we compare the outputs of these electric field models during the September 2017 storm, covering a range of solar wind and interplanetary magnetic field (IMF) conditions. We explore the relationships between the IMF conditions and the model output parameters such as transpolar voltage, the polar cap size and the lower latitude boundary of convection. We find that the electric potential and field parameters from the spacecraft-based models have a significantly higher magnitude than the SuperDARN-based models. We will highlight the similarities and differences in topology and magnitude for each model. | | 27 | Comprehensive analysis of the response of the ionospheric F2-layer to the largest geomagnetic storms from solar cycle #24 over Europe | Berényi, K et al. | Poster | | | K. A. Berényi[1,2], B. Heilig[1,2], J. Urbář[3,4], D. Kouba[3], Á. Kis[1], V. Barta[1] | | | [1]Institute of Earth Physics and Space Science, Sopron, Hungary; [2]Eötvös Loránd University, Budapest, Hungary; [3]Institute of Atmospheric Physics, Bocni II, Prague, Czech Republic; [4]Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143, Italy | | | The complex analysis of the largest geomagnetic storms of solar cycle #24 maximum is our main aim in this study. Our focus is on the ionosphere, more precisely on the ionospheric F2-layer. The selected storm intervals are: 11-17 November 2012 (Kpmax=6.33, Dstmin=-108 nT ), and 16-25 March 2015 (Kpmax=7.67, Dstmin=-228 nT). Data from 5 European digisonde (DPS-4D) stations, ground GNSS TEC, Swarm and TIMED (Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics) satellites have been used for the investigation.
This study is a follow up of Berényi et al. (2018) aiming to validate and strengthen our previous results. We analyze the meridional behaviour of the geomagnetic disturbance caused ionospheric storms to understand and interpret the evolution of the ionosphere’s response.
The storm from 2012 is a no-positive phase (NPP) storm, but the 2015 storm shows typical patterns of a regular positive phase (RPP) storm type (following the categorization by Mendillo and Narvaez, 2010). In both cases a significant increase in electron density of the F2-layer can be observed at dawn/early morning (around 6:00 UT, 07:00 LT). We compared the digisonde foF2 parameter with GNSS TEC data. Moreover, Global Ultraviolet Imager (GUVI) measurements from TIMED satellite was used to investigate the changes in ionospheric O/N2 ratio. Besides, we observed the fade-out of the ionospheric layers at night during the geomagnetically disturbed time periods. In order to determine whether this fade-out is connected to the ionospheric footprint of the plasmapause and the location of the midlatitude ionospheric trough, we analyzed Swarm observations (for the storm 2015), too. | | 28 | Diagnose of the magnetospheric generator properties from in situ and/or optical observations of stable auroral arcs | Lamy, H et al. | Poster | | | Herve Lamy[1], Marius Echim[1], Cyril Simon Wedlund[2], Gaël Cessateur[1], Johan De Keyser[1] | | | [1]BIRA-IASB, Brussels, Belgium; [2]Space Research Institute, Graz, Austria | | | We discuss a method to estimate the properties of a magnetospheric generator using a quasi-electrostatic magnetosphere-ionosphere coupling model and in situ or optical observations of discrete quiet arcs. The method is based on a parametric description of magnetospheric interface generators from Vlasov equilibrium solutions derived for magnetospheric plasma interfaces similar to kinetic tangential discontinuities. For each instance of the generator solution, we solve the current continuity equation to compute the ionospheric electric potential at lower, ionospheric altitudes. Based on the kinetic description of particle dynamics in the mirroring field we can further estimate the field-aligned potential drop between the generator and the auroral ionosphere. Furthermore, we can calculate the field-aligned current density, the flux of precipitating energy, and the height-integrated Pedersen conductance, thus the main properties of the auroral arc. This is how we generate an ensemble of auroral arc solutions, one for each generator instance. The diagnose of the generator properties is performed with a minimization procedure. Indeed, we select one or more observational variables, from optical (e.g. from ALIS network) and/or in-situ measurements (e.g. from DMSP), and estimate an error in the least-square sense by comparing the numerical results with observational data. This way we find which generator model produces auroral arc properties that best fit the observations. The procedure is validated in a case study with observations by DMSP and Cluster and can be generalized to other types of data.
This approach is relevant e.g. for the upcoming joint ESA/CAS SMILE (Solar Wind Magnetosphere Ionosphere Link Explorer) mission in two ways: on the one hand the SMILE FUV imager can provide the general context of the oval, on the other hand SMILE in-situ observations of particles and magnetic field would allow for the verification of the method and its further optimization.
| | 29 | High latitude scintillation detection using TEC provided by multi-frequency professional GNSS receivers | Imam, R et al. | Poster | | | Rayan Imam[1,2], Fabio Dovis[2], Claudio Cesaroni[1], Luca Spogli[1], Lucilla Alfonsi[1] | | | [1]Upper Atmosphere Physics and Radiopropagation Unit, Istituto Nazionale di Geofisica e Vulcanologia (INGV), Italy; [2]Department of Electronics and Telecommunications, Politecnico di Torino, Italy | | | L-band Ionospheric Scintillations at high latitudes are caused mainly by plasma density irregularities in the ionosphere resulting mainly from space weather events. Trans-ionospheric radio waves, like the Global Navigation Satellite Systems (GNSS) signals and satellite communication signals, passing through these irregularities suffer from rapid random fluctuations in the signal intensity and phase. This makes scintillations a threat to these systems, but at the same time makes these systems suitable for monitoring the occurrence of ionospheric irregularities.
GNSS signals have been utilised for monitoring scintillation and ionospheric Total Electron Content (TEC) since the 90s of the last century. Special GNSS receivers, known as ionospheric scintillation monitoring (ISM) receivers, are deployed to monitor scintillation, providing the amplitude and phase scintillation indexes (S4 and respectively), in addition to other scintillation parameters. On the other hand, GNSS multi-frequency receivers are utilised to monitor the ionosphere TEC at a global scale. GNSS receivers in fact have become the default instrument for TEC monitoring with hundreds of receivers distributed around the world providing global coverage. Their distribution is wider and denser than the ISM receivers which are concentrated in few locations, mainly around the polar and equatorial regions. This motivates inspecting the widely available data from GNSS multi-frequency receivers for scintillation studies.
In this paper we present our work on using TEC measurements provided by IGS receivers as scintillation indicators. We focus on detecting scintillation occurrence rather than computing the scintillation indexes from these receivers. We choose the international GNSS service (IGS) receivers’ data because of their availability and for the controlled measurement quality guaranteed by the IGS network. We utilise Machine Learning techniques to develop a model able to detect scintillation occurrence on a GNSS signal based on time series of TEC measured on that specific satellite signal. We analyse the ability of the model to detect strong scintillation and the importance of the model for space weather studies. We use data from ISM receivers quasi-co-located with the IGS receivers as the ground truth for scintillation detection. We focus on detecting phase scintillation and we find that it is possible to detect strong scintillation (>0.5) with high accuracy. Finally, we comment on using the sam | | 30 | The Socioeconomic Impacts of the Upper Atmosphere Effects on LEO Satellites, Communication and Navigation Systems | Mainella, S et al. | Poster | | | Pietro Vermicelli[1]; Sara Mainella[1,2], Lucilla Alfonsi[2], Anna Belehaki[3], Dalia Buresova[4], Reko Hynonen[5],Vincenzo Romano[1,2]; Ben Witvliet[6] | | | [1]SpacEarth Technology Srl, [2] Istituto Nazionale di Geofisica e Vulcanologia, [3]National Observatory of Athens, [4] Institute of Atmospheric Physics of the Czech Academy of Sciences,, [5]Sodankylä Geophysical Observatory, [6]University of Twente | | | The report dedicated to the “Socioeconomic impacts of the upper atmosphere effects” is one of the results of the project PITHIA Network of Research Facilities (PITHIA-NRF), a research infrastructure funded by the European Union’s Horizon 2020 research and innovation program that aims at building a European network integrating observing facilities, data collections, data processing tools, and prediction models for the study of the Earth’s Ionosphere, Plasmasphere, and Thermosphere.
The near-Earth space environment undergoes daily changes driven by variable conditions in the Sun. Explosive eruptions of energy from the Sun causing minor solar storms on Earth are relatively common and of little consequence. On the contrary, rarely occurring superstorms generate physical changes in the Earth’s upper atmosphere detrimental to satellites, signals from global navigation systems, and radio systems. While for these events the physics and engineering repercussions are extensively studied, this is not the case for the related socioeconomic ramifications, despite the growing dependence on these technologies by the modern society. For example, failures in any of these infrastructures may disrupt or render unavailable services of exceptional importance such as power or those (nowadays ubiquitous) relying on accurate positioning, navigation, and timing information such as transport, surveying, or banking. Therefore, our work identifies the infrastructures vulnerable to the upper atmosphere effects and quantifies their impacts on Earth Observations systems (e.g., low-frequency SAR), LEO satellites (e.g., GNSS satellites), Astronomical Observation systems (e.g., LOFAR), systems offering PNT services, and radio systems using HF and VHF communications through a systematic literature review.
Through a literature review on previous space weather socioeconomic impacts we assessed the costs associated with the risks posed to critical space-borne and ground-based technologies by upper atmosphere. These costs are high and comparable to those of terrestrial hazards like tsunamis, earthquakes, or floods. Nevertheless, the quantification of the socioeconomic impacts is not yet mature, partly because of the lack of important modeling information and modern society’s lack of experience with extremely large events. Nonetheless, governments, asset owners, and business managers need advances in this area to mitigate the risks posed by the upper atmosphere space weather. | | 31 | Variations of thermospheric parameters in the Northern Hemisphere during SWWs in January 2008 and 2009 | Perrone, L et al. | Poster | | | L.Perrone *(1)and A.Mikhailov(2,1) | | | (1) Istituto Nazionale di Geofisica e Vulcanologia(INGV), Rome, Italy, e-mail:loredana.perrone@ingv.it (2) Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN), Moscow, Russia; mikhailov71@gmail.com | | | A large part of F2-layer variability is linked to geomagnetic activity; the rest is attributed to ‘meteorological’ sources at lower levels in the atmosphere Sudden stratospheric warming (SSWs) events in January 2008 and 2009 were analyzed.
An original method was used to retrieve aeronomic parameters from observed electron concentration in the ionospheric F-region. Atomic oxygen was shown to be the main aeronomic parameter responsible both for the observed day-to-day and long-term (during SSWs) foF2 variations. Atomic oxygen rather than neutral temperature mainly controls the decrease of thermospheric neutral gas density in the course of the SSW events. Day-to-day variations of thermospheric circulation and an intensification of eddy diffusion during SSWs are suggested to be the processes changing the atomic oxygen abundance in the upper atmosphere for the periods in question.
Recent Global-Scale Observations of the Limb and Disk (GOLD) observations of O/N2 column density confirm the depletion of the atomic oxygen abundance not related to geomagnetic activity during SSWs.
| | 32 | Spatial and temporal distribution of intermittent magnetic field irregularities in the upper ionosphere and their space weather consequences; Study of the Swarm mission magnetic field records | Péter, K et al. | Poster | | | Péter Kovács(1), Balázs Heilig(2), Andrea Opitz(1), Nikolett Biró(1), Gergely Kobán(1), Zoltán Németh(1) | | | (1) Wigner Research Centre for Physics, (2) Institute of Earth Physics and Space Science | | | Small-scale plasma irregularities are frequent phenomena in the ionosphere. In the paper we study the magnetic appearances of these irregularities by using the high-frequency magnetic field records of the Swarm mission triplet. It is argued that the irregularities evolve due to turbulent plasma phenomena exhibiting scale-dependent intermittent plasma and magnetic field fluctuations. Making use of the non-Gaussian behaviour of the intermittent variations, a consecutive statistical analysis has been carried out for sliding-window segments of the more than eight years long magnetic records of the three Swarm spacecraft in order to reveal the typical regions in the upper ionosphere that exhibit intermittent fluctuations. The intensity of the intermittent fluctuations in a segment is measured via the fourth statistical moments (i.e., the kurtosis) of the fluctuations that exceeds a value of three in case of the deviation from Gaussian distribution. This proxy is called intermittency index, in short IMI. It turns out that the most intensive intermittent fluctuations in the transverse magnetic field are apparent in the auroral oval and near to the ionosphere footprint of the plasmapause. These findings are reinforced by published auroral oval boundary and plasmasphere models. Additionally, compressional and transverse magnetic field fluctuations also exhibit intermittent behaviour about the dip equator (symmetrically near the 10° latitude in both hemispheres), due to equatorial spread F and plasma bubble phenomena. Besides the presentation of the spatial/temporal distributions of the revealed intermittent regions, the paper also concerns the space weather consequences of the detected magnetic field irregularities for the propagation of GNSS radio signals. We study the correlation between intermittent irregularities and loss of lock events detected onboard Swarm, as well as the influence of irregularities on scintillation records of ground-based GNSS station networks. | | 33 | A lack of F10.7 consensus: Impacts of varying F10.7 smoothing approaches on global models | Donegan-lawley, E et al. | Poster | | | Elizabeth Donegan-Lawley[1], Sean Elvidge[1], Luke Nugent[1], Alan G. Wood[1], David R. Themens[1] | | | [1]Space Environment (SERENE) group, University of Birmingham, B15 2TT, United Kingdom Corresponding Author Email: e.e.a.lawley@pgr.bham.ac.uk | | | To enable the proper operation, planning and management of space weather services, a comprehensive and timely specification of the Earth’s upper atmosphere are required. The 10.7 cm solar radio flux (known as F10.7) is one of the most commonly used indices of solar activity, and the 81-day average of this value (F10.7A) is often used in ionospheric and thermospheric models2. Two conflicting methods of calculating F10.7A have been used by the scientific community, both of which have led to highly-successful results that have been published in peer-reviewed journals; however, discrepancies between these techniques are substantial and warrant investigation in terms of their implications for space environment modelling.
The first method, centred on the day of interest, averages the preceding and following 40 days to find the value of F10.7A. The second takes the mean of the values for the day of interest and the preceding 80 days. This study highlights the influence of the choice of calculation method of F10.7A on ionospheric model output. Runs of the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIE-GCM) around the solar maxima in 2001 and 2014, using the different calculation methods of F10.7A, have been undertaken, and the differences due to the chosen calculation methods were evaluated. A. The differences vary with location and exceed 7 TECu. With the escalating demand for accurate modelling of the Earth’s upper atmosphere and ionosphere, and the approaching solar maximum, the choice of calculation method of F10.7A has become increasingly important. | | 34 | Spectral numerical study of the development of the Rayleigh-Taylor instability in the MHD-Boussinesq model | Piterskaya, A et al. | Poster | | | Anna Piterskaya[1], Mikael Mortensen[1] | | | [1]Department of Mathematics, University of Oslo, Oslo, Norway | | | Ionospheric plasma is rarely in thermodynamic equilibrium. As a matter of fact, its distinctive nature is often described by density inhomogeneities. The detailed investigation and analysis of such density fluctuations is of great significance. This is essentially in the view of the fact that density inhomogeneity has a significant effect on, among other things, the propagation of radio waves. For that reason, the research about instabilities in the ionosphere is practically interesting for many involved parties. For instance, one can be especially concerned of the continuous operation of satellite systems without major interference.
It is quite often a challenging task when it comes to solving such complex and demanding problems analytically. That being the case requires a necessity for future technological development to create an accurate and fast model. In our research, we investigate the Rayleigh-Taylor instability in three-dimensional space in Cartesian coordinates by using spectral methods. Such instability has been described in various research fields, for instance, inertial confinement fusion, supernova remnants, etc. It is also worth noting that this phenomena is quite often observed in the equatorial ionosphere.
One of the approaches for studying the Rayleigh-Taylor instability is to use a fluid model. This approximation is possible because a plasma becomes macroscopically unstable due to macroscopic density gradients. In our study, we also make use of the Boussinesq conjecture, that eliminates the problem under consideration to a one-fluid model. We solve the equations with the fast and efficient spectral code Shenfun, that provides a spectral order and accuracy. Our main research interest is to study the development of the Rayleigh-Taylor instability for the absent magnetic field and different orientations and magnitudes of the magnetic field. We look at the non-linear flow of the instability and consider different cases with various wavelength modes. The results obtained in this study give a good basis for future development of multi-species code. The presented program provides high spectral convergence for the three-dimensional Rayleigh-Taylor instability problem and shows high accuracy in calculations. | | 35 | Scintillation on transionospheric radio signals | Vasylyev, D et al. | Poster | | | Dmytro Vasylyev, Martin Kriegel, Volker Wilken, Jens Berdermann | | | DLR Institute of Solar-Terrestrial Physics | | | A radio wave propagating in the upper and lower atmosphere of the earth suffers a distortion of phase and amplitude. When it crosses ionospheric irregularities, the radio wave experiences fading, phase distortions, angle of arrival fluctuations. These signal fluctuations are known as scintillation and vary significantly with magnetic and solar activity, day of the year, time of the day, operating frequency, or communication link geometry.
Scintillation phenomena have negative impact on the robust and reliable performance of many services, such as GNSS positioning, navigation, and timing. It is responsible for degradation of images from radio telescopes and synthetic aperture radars. It distorts and degrades signals from communication and remote-sensing satellites. The estimation and forecast of scintillation levels is essential for risk assessment for Ground Based Augmentation Systems.
In our Institute of Solar-Terrestrial Physics we conduct the fundamental research aiming to describe different aspects of scintillation phenomena. We also model scintillation levels by means of numerical simulations in the framework of the Global Ionospheric Scintillation Model (GISM). The scintillation indices obtained with the GISM are planned to be provided as one of the IMPC services. |
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