Session 11 - Space Weather effects in the ionosphere and thermosphere: advances in monitoring, modeling and mitigation techniques
Anna Belehaki (NOA); Jean Lilensten (IPAG/CNRS)
Thursday 30/11, 9:45 - 13:00
ionosphere-thermosphere measurements, ionosphere-thermosphere modelling and forecasting, space weather products and services, proxies, indices, space weather effects, mitigation techniques
The session aims at exploring recent advances in ionosphere-thermosphere measurement techniques (in situ and remote sensing), in modeling, nowcasting and forecasting under all possible space weather conditions, from quiet to extremely disturbed. Emphasis will be given on new space weather products and services derived with the above techniques, including indices and proxies to support communication, navigation, positioning systems, satellites’ orbitography and mitigation technologies.
From Thursday morning to Friday noonTalks
Thursday November 30, 09:45 - 11:00, Delvaux
Thursday November 30, 11:45 - 13:00, DelvauxClick here to toggle abstract display in the schedule
Talks : Time scheduleThursday November 30, 09:45 - 11:00, Delvaux
Thursday November 30, 11:45 - 13:00, Delvaux
|09:45||Long-term variations of exospheric temperature inferred from foF1 observations ||Perrone, L et al.||Oral|
| ||Andrei Mikhailov, Loredana Perrone|
| ||IZMIRAN,Istituto Nazionale Di Geofisica e Vulcanologia|
| ||Long-term trends of upper atmosphere neutral temperature are widely discussed in relation with the thermosphere cooling due to the CO2 concentration increase. Neutral composition and temperature Tex retrieved from ionospheric observations at Sodankylä (auroral zone), Juliusruh and Rome (middle latitudes) ionosonde stations were analyzed for summer (June) noontime conditions over the (1958-2015) period. Linear trends were found to be very small (0.05-0.6)% per decade being practically totally controlled by solar activity long-term variations. The revealed Tex trends have a natural (not anthropogenic) origin and they are due to long-term variations in solar and geomagnetic activity. Large and physically unreal (providing Ti=Tn) trends obtained from ISR observations may be related to the routine IS method when a fixed model of ion composition (O+/Ne ratio and mean ion mass, correspondingly) is used under varying geophysical conditions. Mean ion mass number manifests a negative trend at 175 km which should correspond to a negative trend in Ti contrary the results obtained with ISRs. A general conclusion: routine ISR observations based on a fixed model of ion composition (O+/Ne ratio) hardly can be used for long-term trend analyses.
|10:00||Northern scintillations characteristics and impacts on SBAS behavior: EGNOS Case||Paparini, C et al.||Oral|
| || Ridha Chaggara, Claudia Paparini, Ulrich Ngayap-Youmbi, Bernard Duparc, Sandro Maria Radicella, Luigi Ciraolo |
| ||European Satellite Services Provider, ESSP Toulouse France; Abbia GNSS technologies (Toulouse France) on behalf of ESSP; International Centre for Theoretical Physics, ICTP Trieste Italy|
| ||Ionospheric scintillation remains one of the main contributors to GNSS performance perturbations. In the context of SBAS, the unpredictable nature and the variety of ways it impacts both system and user segments require refined scintillation characterization and understanding to pave the way for the mitigation techniques definition. Alike other SBAS, EGNOS is subject to ionosphere scintillations; while southern ECAC (European Civil Aviation Conference) region is rarely affected by scintillations, it is common to experience service degradations following northern ionosphere disturbance episodes.
Through extensive analysis of EGNOS ground stations archived with data over 6 months period (2014) combined with broadcast SiS (Signal In Space) performance analysis; this paper provides a picture of the way EGNOS has responded during most severe episodes of the latest Solar cycle #24. More precisely, we emphasize the characteristics and the impact of auroral scintillations experienced over the northern part of ECAC at both ground station tracking capabilities and signal in space performance in terms of IGP and GPS monitoring capabilities. Relevant ionosphere indicators such as the AATR (Along ARC TEC Rate) and ROTI (Rate of change of TEC index) are provided. These parameters are based on TEC evaluation through the TEC Calibration Techniques developed by ICTP/ ICT4D laboratory. Their link with ground station receiver’s behavior in terms of L2 Loss of Lock and phase noise is also established.
Further investigations have been conducted in order to assess the AATR inter-correlation level between different ground stations. Results permitted to drive some trends on both space and time correlation of the AATR parameters. The latter gives indications on how ionospheric disturbances propagate under both nominal and severe conditions. For instance, under quite ionosphere, it is shown that AATR cross-correlation between close northern stations is quite high. For distant stations the cross correlation is not straightforward to establish reflecting the complexity of the process.
|10:15||Extremely intense ionospheric ion escape during severe ICMEs||Yamauchi, M et al.||Oral|
| ||M. Yamauchi, R. Slapak, A. Schillings[1,2], and H. Nilsson|
| ||Swedish Institute of Space Physics (IRF), Kiruna; Luleå University of Technology (LTU) Division of Space Technology, Kiruna|
| ||Cluster ion data showed that the flux values during extremely strong ion escape events are outside (no longer the part of) the distribution of the all-time escaping flux, being up to two orders of magnitude above the mean, with the summer hemisphere (high solar EUV flux input) more drastic than the winter hemisphere. Since such extremely strong ion escape events are observed during extremely severe magnetic storms, and since the past statistical studies of the outflow response to external forcing have only been performed for low to moderately high activities but not for extremely high activities, and this is why the observed "no-linear" response, i.e., higher escape flux than the extrapolation from regular conditions in geomagnetic activities was reported in the past. The degree and causes of such "non-linear" response are our future tasks.
We also propose a possible mechanism that contributes the non-linear extraction of the solar wind energy due to the existence of the ionosphere. We particularly examine mass loading effect of ionospheric escaping ions, through which conservation of momentum of two mixes species extracts kinetic energy, and show that the nonlinear effect by mass loading using the observed ion escape value is substantial.|
|10:30||The Australian Bureau of Meteorology Activities for the Ionospheric Modelling: A Regional Approach||Bouya, Z et al.||Oral|
| ||Z. Bouya, M. Terkildsen P. Maher, V. Kumar, G. Patterson|
| ||Space Weather Services, Australian Bureau of Meteorology, Sydney, Australia|
| ||The Australian Bureau of Meteorology through its Space Weather Service (SWS) is focussed both on developing tailored ionospheric products and services for the key customer groups, and supporting the Australian Space Forecast Centre (ASFC) operations. This paper proposes an approach to regional ionospheric Total Electron Content (TEC) modelling using the Spherical Cap Harmonic Analysis (SCHA) and an Empirical Orthogonal Function (EOF) analysis based data assimilation model to map the ionospheric layer parameter foF2. The SCHA model is based on longitudinal expansion in Fourier series and fractional Legendre co-latitudinal functions over a spherical cap-like region including the Australian continent. The assimilative model uses foF2 measurements made with the Australian region vertical incidence sounder network and foF2 values inferred from Culgoora oblique ionospheric soundings. EOF patterns and observations are assimilated to obtain the observed EOF coefficients used to construct the Australian region maps. In this model, an incremental method is used to update an existing decomposition as new data arrives. We outline the design of both models and the chosen parameters. Finally the EOF analysis was used to characterizing the principal spatial and temporal variations of the Australian region Ionosphere .The analysis captures the background climatology of the ionosphere, thereby providing a baseline to improve the understanding and prediction of short-term disturbances.
Keywords: TEC, SCHA, foF2, EOF, Regional
|10:45||The modification of the ionosphere over the thunderstorm area ||Blecki, J et al.||Oral|
| ||Jan Blecki, Ewa Slomińska, Jan Slomiński, Roman Wronowski, Andrzej Kulak, Janusz Mlynarczyk, Roger Haagmans, Michel Parrot|
| ||Space Research Centre PAS, Warsaw; OBSEE, Warsaw; AGH University of Science and Technology,Cracow; ESTEC Noordwijk; LPC2E, Orleans|
| ||The total electrostatic energy associated with charge separation inside a thundercloud is on the order of 1-10 GJ and a substantial fraction of this energy is released in one lightning discharge on time scales less than 1 sec making lightning one of the most spectacular and dangerous phenomena on our planet. One of the important aspects of lightning phenomena at low altitudes is that the energy release is happening in highly localized regions of space leading to formation of spark channels with temperatures ∼25000K and plasma with electron densities exceeding 1017cm−3
TLEs (sprites, jets, elves, halos) are associated with the electromagnetic connections and interactions between atmosphere, ionosphere and magnetosphere and with strong thunderstorm activity.
DEMETER has clearly shown, that thunderstorms and sprites can affected the ionosphere even at altitude of its orbit (680km). The Swarm constellation comprises 3 identical satellites. Two of them are operating on the circular, polar orbits with initial altitude 460 . Third one has also circular orbit, but with altitude 530. The orbits of the first 2 satellites are in almost the same plane, but third one is close to be perpendicular to the first two. The payload containing Vector Field Magnetometer, Absolute Scalar Magnetometer and Electric Field Instrument among other allows to study the effects in the ionosphere generated by thunderstorms. The discussion of the observation done by DEMETER and Swarm satellites will be given in the presentation.
The discussion of the cross correlation between the ground based and Swarm registration of the ULF waves related to the thunderstorm and TLE’s will additionally be presented.
M. Parrot et al. ,Ionospheric density perturbations recorded by DEMETER above intense thunderstorms, J.Geophys.Res., 2013.
Clilverd, M. A et al., Determining the size of lightning- induced electron precipitation patches, J. Geophys. Res., 2002
D.K. Sharma, et al., Lightning induced heating in the ionosphere, Atmosfera, 2004
F. Bourriez, et al.A statistical study over Europe of the relative locations of lightning and associated energetic burst of electrons from the radiation belt, Ann. Geophys. 2016
This work was supported by grant NCN 2014/13/B/ST10/01285 .
|11:45||Specifying the background ionospheric conditions for scientific and operational applications||Tsagouri, I et al.||Oral|
| ||Ioanna Tsagouri, Ja Soon Shim, Maria M. Kusnetsova, Ivan Galkin, Bruno Zolesi, Anna Belehaki, Kostas Koutroumbas and Kostas Themelis|
| ||National Observatory of Athens, Greece; CUA/ NASA GSFC, Greenbelt, MD, USA; NASA GSFC, Greenbelt, MD, USA; Center for Atmospheric Research, University of Massachusetts Lowell, Lowell, Massachusetts, USA; Instituto Nazionale di Geofisica e Vulcanologia, Rome, Italy; CEA Saclay, Service d'Astrophysique Orme des Merisiers, France|
| ||The reliable identification and quantification of space weather effects on the Earth's ionosphere requires the precise representation of the background ionospheric conditions. This is definitely not a straightforward task, since the requirements differ for different applications, ranging from the representation of the quiet-time ionosphere that is important in case one deals with large scale effects (e.g., ionospheric storm effects) up to the challenging distinction between large scale electron density perturbations and travelling ionospheric disturbances. Extra challenges are imposed in case of the operational applications that usually require the relevant information available in real time. In this respect, we propose the systematic assessment of several methodologies available today for the representation of the background conditions in an effort to outline current capabilities and help further improvements. The tests include standard data driven approaches (i.e., monthly medians or running averages using a time window of few minutes to about 30-days), reconstruction of the background variation through spectral processing [FFT analysis and Robust Probabilistic Principal Component Analysis (RPPCA)] and ionospheric models' predictions (e.g., SWIF, SAMI3, IRI, IRTAM) and apply to foF2, MUF and TEC ionospheric parameters.|
|12:00||Geomagnetic and Ionospheric data from the Swarm Mission for the ESA’s SSA SWE Service Network||Kervalishvili, G et al.||Oral|
| ||Guram N. Kervalishvili, Claudia Stolle, Jan Rauberg, Jürgen Matzka, Stefanie Weege, Mirjam Langhans, Nils Olsen, Susanne Vennerstrøm, Magnar G. Johnsen, Chris Hall|
| ||GFZ German Research Centre for Geosciences, Potsdam, Germany; DTU Space, Kongens Lyngby, Denmark; Tromsø Geophysical Observatory (TGO), Tromsø, Norway|
| ||Swarm is the ESA's first constellation mission for Earth Observation, which consists of three identical satellites (Swarm A, B, and C). The spacecraft were launched on 22 November 2013 and on 17 April 2014 the final constellation was achieved. Since then Swarm A and C fly side-by-side at an altitude of about 470 km, whereas Swarm B is orbiting at a higher altitude of about 520 km. All Swarm satellites are equipped with a set of six identical instruments: absolute scalar and vector field magnetometers, star tracker, electric field instrument, GPS receiver, and accelerometer.
A consortium of 9 partners lead by GFZ (German Research Centre for Geosciences, Potsdam, Germany) provides 7 products related to the geomagnetic-ionospheric observations developed within the Swarm Utilisation Analysis (SUA) framework (project of the ESA’s SSA SWE program). Two new and five existing Swarm products build the SUA service that is implemented into Ionospheric Weather and Geomagnetic Conditions Expert Service Centres (ESCs). The Swarm Total Electron Content (TEC), electron density, Ionospheric Bubble Index (IBI), and new developed Rate Of change of TEC (ROT) products are integrated into the Ionospheric Weather ESC. While the other three Swarm products Field-Aligned Current (FAC), Vector Magnetic field components, and location and intensity level of Polar Electrojet (PEJ) are integrated into the Geomagnetic Conditions ESC.
The satellite-based ROT is a major parameter in space weather that describes the small-scale variability of the line of sight electron content resulting from the ionosphere and plasmasphere. ROT is highly relevant for users in navigation and communications because strong plasma gradients cause GPS signal degradation or even loss of the GPS signal. ROT is a relevant space weather asset irrespective of geomagnetic activity (also occurs during quiet geomagnetic times). PEJ has a high-level importance for power grid companies since the polar electrojet is a major cause for ground-induced currents. PEJ gives the possibility to monitor or validate the evolution of the polar electrojet during geomagnetic quiet times and geomagnetic storms, in particular their migration from high- to mid-latitudes. It has a high-level importance for power grid companies since the polar electrojet is a major cause for ground-induced currents.
GFZ also provides the Kp (and Ap) index, which is the planetary three-hour-range index of the geomagnetic activity, to the ESA’s SSA SWE Geomagnetic Conditions ESC. The Kp index is derived from recordings obtained at 13 selected, subauroral and mid-latitude geomagnetic observatories. This index is one of the major parameters used as an input for models (e.g. thermospheric density, the magnetosphere, radiation belt particles, magnetopause location, ionosphere and auroral oval location) and serves as a scale for geomagnetic conditions and alerts in space weather.|
|12:15||New insights into structure of the mid-latitude Ionosphere using LOFAR||Fallows, R et al.||Oral|
| ||Richard Fallows, Maaijke Mevius, Biagio Forte, Sebastiaan van der Tol, and Mario Bisi|
| ||ASTRON - the Netherlands Institute for Radio Astronomy; University of Bath; Rutherford Appleton Laboratory|
| ||The Low Frequency Array (LOFAR) is a radio astronomy array consisting of a dense core of 24 stations within an area of diameter ~4km, 14 stations spread further afield across the north-east of the Netherlands, and a further twelve stations internationally (six across Germany, three in northern Poland, and one each in France, Sweden and the UK). Each station is capable of observing over a wide bandwidth across the frequency range 10-240 MHz, at high time and frequency resolutions. When the stations are combined to image the radio sky using interferometry, the ionosphere can pose a significant challenge in the calibration of signal phase differences between each station. However, a side product of the calibration process is valuable information on ionospheric structures ranging in scale from tens of metres to ~100km. Using only the LOFAR core stations and measuring the position shifts of many radio astronomical sources in a portion of the sky, it is possible to directly image moving ionospheric structures with a time resolution of 1 minute. Furthermore, using single stations in a high time resolution mode enables ionospheric scintillation to be measured. Observations of strong natural radio sources such as Cassiopeia A and Cygnus A taken using LOFAR show almost continual ionospheric scintillation. Dynamic spectra of these observations show scintillation progressing through the weak and strong scattering regimes and sometimes the effects of refraction due to large-scale structure in the ionosphere. For single observing frequencies, the normalised intensities received by each station can be plotted as images where each intensity pixel corresponds to the spatial location of the station. This results in a series of images where the scintillation intensity can be seen 'flowing' across the stations in movies created from them. Such movies demonstrate how the scintillation appears to flow across the compact core area of LOFAR in waves at highly variable speeds, and the small-scale structure which exists well within single pixels of even high-resolution GNSS TEC maps. These novel data will be used to support and test ionospheric and scintillation modelling over a wide range of scales, and a project is underway to monitor TEC gradient variations over Europe, verify GNSS IONEX data and, ulitmately, to implement near real time imaging of ionospheric structures and TIDs.|
|12:30||The ESCAPE M5 mission: first-time systematic study of Thermosphere/Exosphere/Ionosphere for various solar and solar wind conditions||Dandouras, I et al.||Oral|
| ||Iannis Dandouras, Masatoshi Yamauchi, Henri Rème, Johan De Keyser, Octav Marghitu, Andrew Fazakerley, Benjamin Grison, Lynn Kistler, Anna Milillo, Rumi Nakamura, Nicolaos Paschalidis, Antonis Paschalis, Jean-Louis Pinçon, Takeshi Sakanoi, Martin Wieser, Peter Wurz, Ichiro Yoshikawa, Ingemar Häggström, Mike Liemohn, Feng Tian, Ioannis Daglis and the ESCAPE proposal team|
| ||Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse/CNRS/CNES, Toulouse, France; Swedish Institute of Space Physics, Kiruna, Sweden; Royal Belgian Institute for Space Aeronomy, Brussels, Belgium; Institute for Space Sciences, Bucharest-Magurele, Romania; UCL/MSSL, London, UK; Institute of Atmospheric Physics, The Czech Academy of Sciences, Prague, Czech Republic; University of New Hampshire, Durham, USA; INAF/Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy; Institut für Weltraumforschung, Graz, Austria; NASA Goddard Space Flight Center, Greenbelt, USA; National and Kapodistrian University of Athens, Athens, Greece; LPC2E, Orléans, France; Tohoku University, Sendai, Japan; University of Bern, Physikalisches Institut, Bern, Switzerland; University of Tokyo, Kashiwa, Japan; EISCAT Headquarters, Kiruna, Sweden; University of Michigan, Ann Arbor, USA; Tsinghua University,|
| ||ESCAPE is a mission proposed in response to the ESA-M5 call that will quantitatively estimate the amount of escape of the major atmospheric components (nitrogen and oxygen), as neutral and ionised species, escaping from the Earth as a magnetised planet. The spatial distribution and temporal variability of the flux of these elements and their isotopic composition will be for the first time systematically investigated in an extended altitude range, from the exobase/upper ionosphere (500 km altitude) up to the magnetosphere.
The goal is to understand the importance of each escape mechanism, its dependence on solar and geomagnetic activity, and to infer the history of the Earth's atmosphere over a long (geological scale) time period.
Since the solar EUV and solar wind conditions during solar maximum at present are comparable to the solar minimum conditions 1-2 billion years ago, the mission naturally aims at space weather effects on the upper thermosphere, exosphere, and upper ionosphere. The result will be used as a reference to understand the atmospheric/ionospheric evolution of magnetised planets.
To achieve this goal, a slowly spinning spacecraft is proposed equipped with a suite of instruments developed and supplied by an international consortium. These instruments will detect the upper atmosphere and magnetosphere escaping populations by a combination of in-situ measurements and of remote-sensing observations. The measurement target includes densities and temperatures of cold ions/electrons and neutrals in the thermosphere/exosphere/ionosphere, which can directly be compared with the EISCAT_3D observations. The EISCAT_3D, that will be ready by early 2020's, will help distinguishing temporal and spatial structures during spacecraft conjugacies through its continuous monitoring of a 3D-volume of 500 km diameter at ~500 km altitude.
|12:45||Ionospheric impact on Biomass ESA mission||Alfonsi, L et al.||Oral|
| ||Lucilla Alfonsi, Gabriella Povero, Luca Spogli[1,3], Claudio Cesaroni, Cathryn N.Mitchell, Robert Burston, Sreeja Veettil, Marcio Aquino, Virginia Klausner, Marcio Muella, Michael Pezzopane, Alessandra Giuntini,Biagio Forte, Marco Pini, La The Vinh, Ta Hai Tung, Asnawi Husin, Sri Ekawati, Charisma Victoria de la Cruz-Cayapan, Mardina Abdullah, Noridawaty Mat Daud, Minh Le Huy, Nicolas Floury |
| ||Istituto Nazionale di Geofisica e Vulcanologia, Italy; Istituto Superiore Mario Boella, Italy; SpacEarth Technology, Italy; University of Bath, UK; University of Nottingham,UK; Universidade do Vale do Paraíba, Brazil; Hanoi University of Science and Technology, Vietnam; National Institute of Aeronautics and Space (LAPAN), Indonesia; National Mapping and Resource Information Authority (NAMRIA), The Philippines; Universiti Kebangsaan Malaysia (UKM), Malaysia; Institute of Geophysics, Vietnam Academy of Science and Technology, Vietnam; European Space Agency|
| ||Biomass is a polarimetric P-band (435 MHz) synthetic aperture radar (SAR) in a dawn-dusk low Earth orbit. Its principal objective is to measure biomass content and biomass change in all the Earth’s forests. The mission launch is envisaged around 2020, for five years duration.
The ionosphere introduces Faraday rotation and scintillations on every pulse emitted by low-frequency SAR, impacting the quality of the imaging. Some of these effects are due to Total Electron Content (TEC) and its gradients along the propagation path. Then, to support the Biomass operations an accurate assessment of the ionosphere morphology and dynamics is necessary, especially in the equatorial and tropical regions. To the scope, we have conducted an in-depth investigation of the significant noise budget introduced by the two crests of the Equatorial Ionospheric Anomaly (EIA) over Brazil and South-East Asia. This investigation is the core of two projects funded by ESA, named IRIS (Ionospheric Research for Biomass in South America) and IBISCO (Ionospheric environment characterization for Biomass Calibration over South East Asia).
The work performed is characterized by a novel approach to conceive a SAR-oriented ionospheric assessment, aimed at detecting and identifying spatial and temporal TEC gradients, including scintillation effects, by means of GNSS ground-based monitoring stations.
The paper presents the main results in terms of climatological assessment of the main features characterizing the ionospheric sectors under investigation and describing worst-case scenarios under harsh space weather conditions. The description here presented includes 3D representation of the TEC spatial and temporal gradients and of the amplitude scintillations.
As the novelty of the adopted approach, the high spatial resolution representation of the ionospheric features here presented is proposed to support the development of techniques capable to mitigate the ionospheric impact on Earth observation missions.
|1||Variation of foF2 in Rome observatory during solar minimum in the last three solar cycles||Perrone, L et al.||e-Poster|
| ||A. Ippolito L. Perrone and C. Cesaroni|
| ||Istituto Nazionale di geofisica e Vulcanologia|
| ||The last three solar cycles have been considered for a study on the variation of the ionospheric parameter foF2 during the solar minimum. Hourly observations recorded by the ionospheric station of Rome have been considered for the years 1985, 1986, 1987, 1995, 1996, 1997, 2007, 2008 and 2009. A background value of foF2 have been computed considering a 27-day running median. A variation of foF2 of more than ± 15% over the background level and with a minimum duration of 3 hours, is here considered as an anomaly. For each anomaly, a study of the geomagnetic condition has been carried, considering the value of the Ap index at the time when the anomaly is detected and for the previous 24 hours. The auroral electrojet index AE has also been investigated in relationship with each observed foF2 anomaly, considering 6 hours before the occurrence of the anomaly since TADs, related to upsurges of auroral activity, can reach middle latitudes and consequently perturb the F2 layer. A characterization of the observed foF2 anomalies with respect to the related geomagnetic conditions is presented in this work.|
|2||Variation of Total Electron Contents (TECs) during the last solar minimum in Rome||Cesaroni, C et al.||e-Poster|
| ||Alessandro Ippolito, Claudio Cesaroni, Luca Spogli|
| ||Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy|
| ||The last solar minimum (2007-2009) has been considered to identify anomalous behaviours of Total Electron Content (TECs) variations in relationship with geomagnetic Ap and AE indexes. The aim of this work is to investigate anomalies in TECs variations during quiet geomagnetic conditions. To the scope, calibrated vertical TEC (vTEC) data, recorded every 15 minutes from the GNSS receiver of the Rome station, have been studied and a background value has been defined through the vTEC monthly median. A variation of vertical TEC of more than ± 2σ over the background level, and with a minimum duration of 1 hour, is what in this work is considered as an anomaly. Each observed anomaly has been associated to the related geomagnetic conditions: for each event, the value of the Ap index at the time when the anomaly is detected, and for the previous 24 hours, is taken into account. The auroral electrojet index AE has also been investigated, considering the AE values up to 6 hours before the occurrence of the anomaly. A characterization of the observed vTEC anomalies with respect to the related geomagnetic conditions, is here presented.|
|3||Real-time identification of travelling ionospheric disturbances based on high frequency reflected radio pulses||Belehaki, A et al.||e-Poster|
| ||Anna Belehaki, Bodo Reinisch, Ivan Galkin, David Altadill, Tobias Verhulst, Jens Mielich, Dalia Buresova, Daniel Kouba and the Net-TIDE project team|
| ||National Observatory of Athens, IAASARS, Greece; Lowell Digisonde International, USA; University of Massachusetts Lowell, Space Science Laboratory, USA; Observatori de l’Ebre, Universitat Ramon Llull, Roquetes, Spain; Royal Meteorological Institute, Belgium; Leibniz-Institute of Atmospheric Physics, Germany; Institute of Atmospheric Physics, Czech Academy of Sciences, Czech Republic; https://sites.google.com/site/spsionosphere/network |
| ||Travelling ionospheric disturbances (TIDs) constitute a threat for operational systems using ground based HF and trans-ionospheric VHF-UHF radiowave propagation. TIDs can impose disturbances with amplitudes of up to ~20% of the ambient electron density, and a Doppler frequency shifts of the order of 0.5 Hz on HF signals. Therefore their identification and tracking is important for the reliable operation of critical systems using the ionosphere as an essential part or for systems for which the ionosphere is fundamentally a nuisance. The Net-TIDE project has developed a warning system for real-time identification of TIDs using skywave Doppler frequency and angle-of-arrival measurements. Data are collected from network-coordinated HF sounding between pairs of European DPS4D and processed in real-time for the calculation of the angles-of-arrival and Doppler frequencies of ionospherically reflected high-frequency (HF) radio signals. The outcome is provided in real-time to the users to characterise TID activity over Europe based on the measured signal parameters. Complementary methodologies based on the analysis of vertical sounding parameters are currently exploited as verification means to improve the confidence level of the warnings. The resulting map of TID activity is updated every 5 minutes to enable the end-users enabling them to put into action specific mitigation techniques to protect their systems.|
|4||SID monitor from Paris Observatory||Briand, C et al.||e-Poster|
| ||Carine Briand, Sofiane Mezziani|
| ||LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité|
| ||A Sudden Ionospheric Disturbances monitor has been implemented at the Paris Observatory. Since January 2017 it routinely monitors the ionospheric fluctuations. In this poster we will explain the implementation phase (in particular the reduction for the noise), show the first results and details the future plans for the operations.|
|5||The detection of ultra-relativistic electrons in low Earth orbit||Katsiyannis, T et al.||e-Poster|
| ||Athanassios Katsiyannis, Marie Dominique, Viviane Pierrard[2,3], Graciela Lopez Rosson[2,3]|
| ||Royal Observatory of Belgium, Solar-Terrestrial Centre of Excellence, Avenue Circulaire 3, 1180, Belgium; Royal Belgian Institute for Space Aeronomy, Ringlaan 3, 1180, Belgium; Universit\'e Catholique de Louvain (UCL), Centre for Space Radiations (CSR), Earth and Life Institute (ELI), Place Louis Pausteur 3, bte L4.03.08, B-1348, Louvain-La-Neuve, Belgium|
| ||To better understand the radiation environment in low Earth orbit (LEO), the analysis of in-situ observations of a variety of particles, at different atmospheric heights, and in a wide range of energies, is needed. We present an analysis of energetic particles, indirectly detected by the Large Yield RAdiometer (LYRA) instrument on board ESA's Project for On-board Autonomy 2 (PROBA2) satellite as background signal. Combining Energetic Particle Telescope (EPT) observations with LYRA data for an overlapping period of time, we identified these particles as electrons with an energy range of 2 to 8 MeV. The observed events are strongly correlated to geo-magnetic activity and appear even during modest disturbances. They are also well confined geographically within the L=6 McIlwain zone, which makes it possible to identify their source. Although highly energetic particles are commonly disturbing data acquisition of space instruments, we show in this work that ultra-relativistic electrons with energies in the range of 2-8 MeV are detected only at high latitudes, while not present in the South Atlantic Anomaly region.|
|6||The Limadou project on the CSES space mission: Study of seismo associated phenomena.||Perrone, L et al.||e-Poster|
| ||A. De Santis, C. Cesaroni, G. Cianchini, R. Di Giovambattista, A. Ippolito, D. Marchetti, L. Perrone and A. Piscini|
| || Istituto Nazionale di geofisica e Vulcanologia|
| ||From data collected from satellites and ground-based instruments, the project deals with the study of what happens during the phase prior to major earthquakes, to possibly identify any preceding pre-earthquake anomalous signal from space and ground. Limadou started on November 2016 , and will last the next three years and the Istituto Nazionale di Geofisica e Vulcanologia is part of this project.
The project aims at studying the preparatory phase of large earthquakes through the analysis of electromagnetic and particle data from sensors onboard the CSES satellite that should be launched before the end of this year. The most important objective is to capture the information exchanged between the two layers (lithosphere and upper atmosphere) through the integration of the data acquired by the CSES satellite with those collected by other satellites(as SWARM and CHAMP) and measured by ground- based (seismic, GPS, ionosonde, magnetic, etc.) stations. Selection of the magneto-ionospheric data is critically based on the space weather condition of ionosphere and magnetosphere. In this presentation, the working break down structure of the project is shown.
|7||A new 3D electron density nowcast and forecast service for the Ionosphere Monitoring and Prediction Center based on gradient enhanced kriging and SMART+||Minkwitz, D et al.||e-Poster|
| ||David Minkwitz and Tatjana Gerzen|
| ||German Aerospace Center, Institute of Communications and Navigation, Kalkhorstweg 53, 17235 Neustrelitz, Germany|
| ||In the recent years different data assimilation techniques have been developed aiming at the reliable estimation of the driving parameters of the ionosphere-thermosphere system. Commonly the algorithms update the initial guess of a physical or empirical background model of the ionosphere by various linear and weakly non-linear measurements. Each algorithm is characterized by specific pros and cons and hence the combination of them is suggested as beneficial.
In this presentation we give an overview on the preparation of a new service for the Ionosphere Monitoring and Prediction Center (IMPC) of the DLR. This service will provide a nowcast and forecast of the ionospheric electron density including layer characteristics, like the critical frequencies and their related peak heights, and the slant total electron content (STEC). So far, these parameters have been delivered to the IMPC by a 3D electron density reconstruction depending on the sensitive assumption of a constant slab thickness and restricted to the application of already smoothed VTEC measurements.
We develop two novel and complementary tomography approaches to upgrade the IMPC service: Gradient Enhanced Kriging (GEK) and the algebraic reconstruction technique SMART+. Both data assimilation techniques are capable to assimilate direct and indirect ionospheric measurements of the electron density and can be operated with any empirical or physical background model. Like the most 3D data assimilation techniques, SMART+ introduces a voxelization of the ionosphere and thus requires calculations of the intersection geometry, whereas the mathematical framework of GEK avoids this step. In order to interpolate between measurements, the correlation lengths of the electron densities in latitude, longitude, height and time direction are of special interest. GEK estimates the correlation lengths from the measurements with maximum likelihood estimation. Contrary SMART+ chooses them empirically and has consequently a reduced computation time. Based on the optimized temporal correlation lengths, a forecasting algorithm is designed.
|8||Hemispheric asymmetry of ionospheric scintillations during the 2015 St. Patrick’s Day storm||D'angelo, G et al.||e-Poster|
| ||Giulia D’Angelo, Mirko Piersanti[2,3], Igino Coco, Lucilla Alfonsi, Luca Spogli[4,5]|
| ||Dipartimento di Matematica e Fisica, Università degli Studi “Roma Tre”, Rome, Italy; Dipartimento di Scienze Fisiche e Chimiche, Università di L’Aquila, L’Aquila, Italy; Consorzio Area di Ricerca in Astrogeofisica, Università di L’Aquila, L’Aquila, Italy; Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy; SpacEarth Technology, Rome, Italy.|
| ||The storm onset on March 17th, 2015 triggered several fluctuations of the electron density in the ionosphere causing severe scintillations at high latitudes on both hemispheres. The GPS Scintillation and TEC Monitor (GISTM) receivers located at Eureka (79.99°N, 274.10°E), Concordia (75.10°S, 123.35°E), Resolute Bay (74.75 °N, 265.00 °E), Baia Terranova (74.41°S, 164.10°E), Ny Ålesund (78.92 °N, 11.98 °E) and Zhongshan (69.37 °S, 76.37 °E) recorded several phase scintillation events, characterized by significant inter-hemispherical asymmetries, mainly in the intensity. The configuration of the ionospheric convection cells, derived by SuperDARN, confirms such asymmetries. Moreover, the observed scintillations appear to be associated to a turbulent regime underlying the ionospheric irregularities dynamics, as the SuperDARN spectral widths seem to suggest. This turbulent regime, indeed, seems to be also the cause of the differences in the density increases, recorded by Swarm satellite, between two hemispheres.
This scenario is ruled by the magnetosphere-ionosphere coupling established after the impact at the magnetopause of the interplanetary shock related to the storm and, later on, of the first Interplanetary Coronal Mass Ejection (Liu et al., 2015). The observations provided by the GOES 15 geosynchronous spacecraft, supported by a modified Tsyganenko and Sitnov model (Tsyganenko and Sitnov, 2005), have been analysed to reconstruct the configuration assumed by the magnetospheric field lines on the 17th of March 2015.
Our study demonstrates how the complementary use of satellite and ground-based observations of the ionosphere and the magnetosphere can allow a detailed description of the ionospheric irregularities causing scintillations. In this work, we show how the asymmetry in the occurrence of the ionospheric phase scintillations over the two hemispheres could be explained by the reconstructed magnetosphere configuration.|
|9||Plasma Impedance of Ne using an Ejectable System experiment (PIONeERS)||Angling, M et al.||e-Poster|
| ||Jonathan Camillieri, Hannah Swinbourne, Chloe Weyham, Matthew J. Angling|
| ||University of Birmingham, Birmingham, UK|
| ||Measurements of the density of the ionosphere can be used to improve ionospheric models and thereby mitigate its impact on systems. Whilst measurements are often made of the bottom-side ionosphere (i.e. below the height of the peak density) using ground based radar systems, and trans-ionospheric integrated measurements can be made using GPS, top-side measurements require satellite based instrumentation.
The ionospheric Impedance Probe (ImP) is being developed to provide in-situ measurements of the top-side ionospheric electron density. ImP can either be used as a secondary payload on a cubeSat class satellite, or, it can be hosted on a dedicated very small spacecraft such as a PocketQube. A PocketQube is a small satellite measuring 5x5x5 cm. Ideally, many ImPs will be flown to provide a high spatial and temporal measurement resolution.
ImP will estimate the ionospheric electron density by exciting an antenna embedded in the ionospheric plasma over a range of frequencies and measuring the frequency of the Upper Hybrid Resonance (UHR). Since the UHR of the plasma is directly dependent on the plasma frequency, it can be used to estimate the electron density It is also dependent on the magnetic field which can be obtained from an on-board magnetometer or modelled.
A variant of ImP (the Plasma Impedance of Ne using an Ejectable System experiment, PIOneERS) is being designed for launch on the REXUS 24 sounding rocket. REXUS is a programme organised by the Swedish and German space agencies (SNSB and DLR respectively), whereby university students can launch their experiments on board a sounding rocket. A variant of ImP will be deployed at the end of a 1.75 m boom at the top of sounding rocket. This will enable testing in the bottom-side ionosphere, whilst the boom keeps the probe away from any potentially strong artificial magnetic field caused by the rocket body.
The e-poster will highlight some of the public engagement materials that have been developed as part of the PIONeERS project.
|10||The UAH-SID monitoring station||Cid, C et al.||p-Poster|
| ||Fernando Montoya, Alberto Garcia, Antonio Guerrero, Judith Palacios, and Consuelo Cid|
| ||Universidad de Alcala|
| ||Sudden Ionospheric disturbances (SIDs) produced by solar flares can be detected by monitoring the power received by VLF radio communication. The UAH-SID monitoring station is located at the University of Alcala, Spain. It has been developed by students of the Telecommunications Degree working under the supervision of researchers from the Space Weather group. This contribution describes the station and its measurements recorded during the recent 2017 September X-class flares and presents the benefits of a European network of SID monitors to nowcast ionospheric disturbances.|
|11||Retrieval of O and N2 distributions from PROBA2-LYRA occultation data||Dominique, M et al.||p-Poster|
| ||Marie Dominique, Edward Thiemann|
| ||Royal Observatory of Belgium; LASP - University of Colorado |
| ||LYRA is a solar EUV/VUV radiometer that flies on-board PROBA2, an ESA micro-mission. LYRA monitors the solar irradiance in four broad channels: Lyman-alpha (120-123 nm), Herzberg (190-222 nm), Aluminum (1-80 nm), and Zirconium (1-20 nm).
The PROBA2 heliosynchronous orbit generates brief occultations three months per year. These enabled studying the O and N2 number density profiles in the 150-450 km range of altitude by Abel Inversion of the estimated line-of-sight column densities. LYRA’s high cadence and signal to noise ratio offer the possibility to reach a very favourable vertical sampling, unfortunately counterbalanced by the extent and inhomogeneity of solar source.
The chosen inversion method takes these hurdles into account by dividing the PROBA2/SWAP near-real-time images of the Sun into parcels and analyzing the contribution of each parcel independently. The main sources of errors are discussed and the retrieved densities are compared to the MSISE-00 and DTM models.
|12||Using platform magnetometers to observe and detect Space Weather events||Doornbos, E et al.||p-Poster|
| ||Eelco Doornbos, Claudia Stolle, Martin Rother, Ingo Michaelis, Gang Lu, Lotfi Massarweh[1,4], Alessandra Menicucci, Elisabetta Iorfida|
| ||Faculty of Aerospace Engineering, Delft University of Technology; Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences; High Altitude Observatory, National Center for Atmospheric Research; Deimos Engenharia|
| ||Magnetic field measurements are an essential tool for space weather monitoring. The space weather community makes use of data from dedicated magnetic observatories, both on Earth and in space. Scientific magnetometers in space are often mounted on long booms to minimise magnetic interference from the spacecraft subsystems, and their data are made available in the form of carefully calibrated science products. However, many satellite missions that are not dedicated to space weather also carry fluxgate magnetometers, for example as part of their attitude control subsystem. These measurements are used directly on-board the satellite as input to an attitude determination and control loop, and are only send down in a housekeeping data stream, stored for possible engineering diagnostic purposes.
In this study, we have investigated the feasibility of using data from such non-dedicated magnetometers for space weather use. We have analysed the housekeeping telemetry data from ESA’s GOCE and Swarm missions, in order to investigate the feasibility of calibrating their platform magnetometers and using this data for monitoring high-latitude field-aligned currents. We have compared the results with those derived from the science instruments on CHAMP and Swarm, as well as AMIE output during the geomagnetic storms of April 5, 2010 (GOCE) and March 17, 2015 (Swarm). Although the noise level and disturbances of the non-dedicated instruments, as well as the time sampling of the housekeeping data pose some limitations, these observations can definitely be seen as a valuable additional space weather asset, especially if similar processing can be extended to multiple missions in the future.
In addition, we have analysed the magnetometer data delivered by the diagnostics subsystem on ESA's LISA Pathfinder, and compared it to the commonly used IMF data from the space weather observatories ACE and DSCOVR, also orbiting the Sun-Earth L1 point. Due to the very stable and clean spacecraft design, the LISA Pathfinder IMF data compares very well with the IMF data from the dedicated missions, when a minimum time resolution of a few minutes is considered. The simultaneous availability of IMF data from three positions close to the Sun-Earth L1 point during parts of 2016 and 2017, opens up possibilities for an accurate assessment of the data quality, as well as enhanced studies of the propagation of the solar wind near the Earth.|
|13||Space weather monitoring project at the Normal Lockyer Observatory, UK||Bingham, S et al.||p-Poster|
| ||William Borrows, Lucia Calverley, Daniel Gymer, Amy Hampshire, Thomas Ledgerwood, Stephanie O’Neil, Rowan Walker-Gibbons, Sharon Strawbridge, Iain Grant, Alan Shuttleworth, Ken Bailey, Suzy Bingham, Steve Marple, Ez Balci|
| ||University of Exeter; Norman Lockyer Observatory; Met Office; University of Lancaster; New Signature UK Ltd.|
| ||We present initial progress on a third year undergraduate space weather project at the University of Exeter. The project focus is the monitoring of space weather at the Norman Lockyer Observatory (NLO), Sidmouth, south-west UK.
The project is composed of two parts. The first part is to assemble a device capable of detecting solar flares and other sudden ionospheric disturbances (SIDs). As such, we are in the process of building a radio antenna and installing a SuperSID monitor at the NLO; the monitor was developed by Stanford University. The data that it collects will be automatically uploaded to Stanford University’s centralised data server where anyone can access it for analysis.
The second part involves a Raspberry-Pi based magnetometer that had previously been installed at the NLO; this measures changes in the Earth’s magnetic field and can therefore detect geomagnetic storms. It is our intention to upload data automatically from the magnetometer to the Met Office’s Weather Observing Website (WOW), which is a platform for amateur observers to upload their own weather data.
|14||Effects of Thermosphere Total Density Perturbations during Severe Conditions, as revealed by the GRACE mission||Deleflie, F et al.||p-Poster|
| ||Florent Deleflie, Carine Briand, Muhammad Ali Sammuneh, Richard Biancale |
| ||IMCCE / Observatoire de Paris/GRGS, PSL Research University, Université Lille1, 77 Avenue Denfert Rochereau 75014 Paris, France , firstname.lastname@example.org; Observatoire de Paris, LESIA, 5 Place Jules Janssen, 92195 Meudon Cedex, France; Centre National d'Etudes Spatiales, Avenue Edouard Belin, 31000 Toulouse, France|
| ||This poster builds a bridge between solar activity and changes induced in the thermosphere total density, as revealed by perturbations induced on the trajectories of the two spacecraft of the GRACE mission, flying in a LEO orbit around the Earth. The study is based on a comparison between the non gravitational accelerations as modelled by accelerometric data on the one hand, and on usual models for non gravitational forces (and more specifically the atmospheric drag) on the other hand.
We identify over the period 2002-2017 a list of solar events that may be representative of the conditions that may heat the terrestrial atmosphere, in terms of geometrical configurations (solar event with a direction that can induce, or not, changes in the Earth's atmosphere) and the intensity of solar activity ; the goal is to identify whether these events have impacted or not the thermospheric density at some relevant altitudes where tracking data are available ; a careful comparison between precise results obtained with accelerometric data, using different atmospheric drag modelling, is provided.
The GRACE mission is made up of two spacecraft flying the Earth in the same (quasi-) polar orbit at a low altitude, and separated one from another by a distance of a few hundreds of kilometers. The paper shows the sensitivity of the trajectories perturbed by changes, in space and time, of the atmospheric density. It shows as well some of the problems that may occur when looking for a reliable link between the trajectories of artificial satellites and the way atmospheric drag models do depend from solar activity. |
|15||Climatological behaviour of the Total Electron Content at the South Pole||Bergeot, N et al.||p-Poster|
| ||Nicolas Bergeot, Jean-Marie Chevalier|
| ||Royal Observatory of Belgium|
| ||The understanding of the impact of solar activity on polar regions upper atmosphere is not as strong as compare to low and mid-latitudes due to lack of experimental observations, especially over Antarctica.
To characterize the differences in the ionosphere-plasmasphere total electron content (TEC) climatological patterns over Antarctica, we reprocessed the GNSS (GPS + GLONASS) data available since 1999 up to now for stations situated at latitudes below S50°. For that, we used the data from POLENET/IGS networks and stations installed around the Princess Elisabeth polar Base (Utsteinen, North-East Antarctica).
The estimated TEC data set is then employed to constrain an empirical model to predict the TEC from F10.7P solar index in entrance using a least-square adjustment. To minimize the differences between the modelled and observed vTEC we considered: (1) an eight-order polynomial function with monthly coefficients between the TEC and F10.7P; (2) a discretization with respect to different zones over Antarctica region to highlight different climatological patterns; (3) different time definitions such as Solar Local Time, Magnetic Local Time, and UTC.
From the output of this model we discuss the different climatological behaviors identified in the ionosphere-
plasmasphere TEC at these high latitudes. Finally, we show some examples of typical TEC disturbances observed during extreme solar events.
|16||September 2017 ionospheric storm effects observed in the Pruhonice station||Mosna, Z et al.||p-Poster|
| ||Zbysek Mosna, Daniel Kouba, Petra Koucka Knizova, Dalia Buresova, Tereza Sindelarova, Jaroslav Urbar[1,2], Jaroslav Chum|
| ||Institute of Atmospheric Physics, CAS, Prague; UiT, Norway, Tromso|
| ||We show first results from the ionospheric vertical sounding campaign performed during the September 2017 ionospheric storm at the Pruhonice station (50N, 15E). Vertical ionograms show unusual ionospheric activity demonstrated by fade-outs, spread conditions, presence of ionospheric cusps, fork shaped iongrams, and rapid changes in electron concentration. We demonstrate wave activity recorded during the studied period. |
|17||Digisonde drift measurement during the September 2017 storm||Kouba, D et al.||p-Poster|
| ||Daniel Kouba, Zbysek Mosna, Petra Koucka Knizova, Dalia Buresova, Tereza Sindelarova, Jaroslav Urbar[1,2], Jaroslav Chum|
| ||Institute of Atmospheric Physics, CAS, Prague; UiT, Norway, Tromso|
| ||We show results from manually processed drift data recorded by the European stations during September 2017 storm. The data well demonstrate wave activity (TID) above the stations. The simultaneous observation at different stations allows us to detect source regions and estimate main wave parameters. |
|18||New Space Weather Instrumentation in Support of EISCAT_3D||Ulich, T et al.||p-Poster|
| ||Thomas Ulich, Antti Kero, Johannes Norberg[1,2], Mikko Orispää, Tomi Teppo, Juha Vierinen, Lassi Roininen[1,4], Tero Raita, Markku Lehtinen, Esa Turunen|
| ||Sodankylä Geophysical Observatory, University of Oulu, Finland; Finnish Meterological Institute, Helsinki, Finland; UiT-The Arctic University of Norway, Tromsø, Norway; Imperial College, London, UK|
| ||Sodankylä Geophysical Observatory has recently attracted grants from the European Regional Development Funds for Lapland through the Regional Council of Lapland in Finland. These grants are dedicated to the development of two new sets of instruments through SGO's Radio Science Laboratory. A new type of ionospheric tomography receiver has been developed and ten such receivers have been deployed this summer. Furthermore, a set of seven Spectral Riometers is under construction and we expect deployment in summer 2018. Both instruments are based on the same concept in that they are Software Radio receivers. Here we report on the status of the development.|
|19||Data analysis and simulation of Plasma Flow Vortices in the Magnetotail||Chargazia, K et al.||p-Poster|
| ||Kh. Chargazia, O. Kharshiladze, G. Zimbardo, J, Rogava|
| ||Iv. Javakhishvili Tbilisi State University; Iv. Javakhishvili Tbilisi State University; Universita’ della Calabria; Iv. Javakhishvili Tbilisi State University, |
| ||Ulf electromagnetic planetary waves can self-organize into vortex structures (monopole, dipole or into vortex chains). They are often detected in the plasma media, for instance in the magnetosheath, in the magnetotail and in the ionosphere. Large scale vortices may correspond to the injection scale of turbulence, so that understanding their origin is important for understanding the energy transfer processes in the geospace environment. In a recent work, the THEMIS mission has detected vortices in the magnetotail in association with the strong velocity shear of a substorm plasma flow (Keiling et al., J. Geophys. Res., 114, A00C22 (2009), doi:10.1029/2009JA014114), which have conjugate vortices in the ionosphere. By analyzing the THEMIS data for that event, we find that several vortices can be detected together with the main one, and that the vortices indeed constitute a vortex chain. The study is carried out by analyzing both the velocity and the magnetic field measurements for spacecraft C and D, and by obtaining the corresponding hodograms. It is found that both monopolar and bipolar vortices may be present in the magnetotail. The comparison of observations with numerical simulations of vortex formation in sheared flows is also discussed.
|20||Complex Dynamics of Equatorial Scintillation||Piersanti, M et al.||p-Poster|
| ||M. Piersanti, L. Spogli[4,6], A. Cicone, L. Alfonsi, M. Materassi, V. Romano[4,6] and R.G. Ezquer[7,8,9]|
| ||Department of Physical and Chemical Sciences, University of L’Aquila. Italy; Consorzio Area di Ricerca in Astrogeofisica. L’Aquila, Italy; National Research Council, Institute for Complex Systems ISC-CNR, Italy; Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy; Department of Information Engineering, Computer Science and Mathematics, University of L’Aquila, Italy; SpacEarth Technology, Rome, Italy; Laboratorio de Ionósfera, Departemento de Física, FACET, Universidad Nacional de Tucúman, Tucúman, Argentina; CIASUR, Facultad Regional Tucúman, Universidad Tecnológica Nacional, Tucúman, Argentina; Cansejo Nacional de Investigaciones Cientifíca y Técnicas, Buenos Aires, Argentina. |
| ||Radio power scintillation, namely highly irregular fluctuations of the power of trans-ionospheric GNSS signals, is the effect of ionospheric plasma turbulence. The scintillation patterns on radio signals crossing the medium inherit the ionospheric turbulence characteristics of inter-scale coupling, local randomness and large time variability. On this basis, the remote sensing of local features of the turbulent plasma is feasible by studying radio scintillation induced by the ionosphere. The distinctive character of intermittent turbulent media depends on the fluctuations on the space- and time-scale statistical properties of the medium. Hence, assessing how the signal fluctuation properties vary under different Helio-Geophysical conditions will help to understand the corresponding dynamics of the turbulent medium crossed by the signal.
Data analysis tools, provided by complex system science, appear to be best fitting to study the response of a turbulent medium, as the Earth’s equatorial ionosphere, to the non-linear forcing exerted by the Solar Wind (SW). We have analysed the radio scintillation and ionospheric fluctuation data at low latitude focusing on the time and space multi-scale variability and on the causal relationship between forcing factors from the SW environment and the ionospheric response.|
|21||Evaluating the dependence of the foF2 parameter variation on geomagnetic activity during the maximum of the #24 solar cycle at midlatitude||Berényi, K et al.||p-Poster|
| ||K. A. Berényi[1,2], Á. Kis, V. Barta|
| ||Geodetic and Geophysical Institute, RCAES, HAS, Hungary;Eötvös Loránd University, Budapest|
| ||In our study we analyzed the differences between the effect of CME-related and of HSS/CIR-related geomagnetic storms in the ionospheric F2-layer during the maximum of the recent #24 solar cycle (2012-2015). These effects were investigated by taking into consideration the seasonal and daytime variations too. We used the ionospheric foF2 parameter from the midlatitude ionosonde of Széchenyi István Geophysical Observatory (IAGA code: NCK) in this work. A total number of 62 geomagnetic storm periods were analyzed: 21 from summer and 41 from winter time periods. In the main phase of the storms we compared the data of the foF2 parameter with the global geomagnetic Dst-, Kp- and AE-index.
In summer at noon the CME-related disturbances decrease the foF2 parameter (negative ionospheric storm effect), while the HSS/CIR-related geomagnetic storms triggers an increase (positive ionospheric storm effect) in the F2-layer parameter value as a function of geomagnetic storm magnitude. On the other hand, the dawn data doesn't show such a reverse effect: both storm types causes decrease in the foF2 parameter value.
In winter time period the noon data presents a much more scattered behavior during CME-related disturbances which makes impossible to establish a trend (positive or negative) as a function of storm magnitude. At the same winter time period we can observe a clear increase in the foF2 parameter value during HSS/CIR-related disturbances as a function of geomagnetic storm magnitude.
The response of ionospheric parameter values to a geomagnetic storm are very similar at dawn during summer and winter: slight decrease.
We can conclude that in summer the effect on ionospheric parameters of both geomagnetic storm types is more significant than in winter. Another conclusion is that while the Kp-index does not correlate well with the ionospheric parameter values, the Dst index shows a very good correlation with the ionospheric parameter values during a geomagnetic disturbance.|
|22||First estimation of the suprathermal electron momentum in the upper ionosphere||Marif, H et al.||p-Poster|
| ||Hanane Marif, Jean Lilensten|
| ||Université des Sciences et de la Technologie Houarie Boumedienne, Algérie|
| ||The ionospheric electron population is divided into two groups. The ambient electrons are thermalized. Their energy is usually smaller than one electronvolt. Their densities and temperatures are the usual ones measured by incoherent scatter radars, or modelled by international codes such as IRI. There is however a second population called the suprathermal electrons. This one is either due to photoionisation or to electron impact between the thermosphere and the precipitation in the high latitude zone. In the frame of space weather, it may be the source of scintillations, plasma bulks…
The suprathermal electron population cannot be measured and had never been modelled. Its modelling requests the computation of the electrons stationary flux f by solving the Boltzmann transport equation. This flux is multiplied by various powers of the velocity and integrated to obtain the momentums. By integrating f over v0 dv, one deduces the suprathermal electron density. An integration of v.f dv allows to compute their mean velocity. Higher momentums give access to their temperature and finally to their heat flux.
We demonstrated for the first time the full and rigorous calculation of momentums up to 3, correcting errors that had been made in the literature (which prevented from computing them up to now). As two case studies, we focussed on high latitude in the auroral oval and low magnetic latitude over Algier.
In this communication, we will show briefly the process for the computation of the momentums, and demonstrate the results. We will compare them to the thermal electron parameters (density, temperature, velocity).|
|23||Multi-station basis for Polar Cap (PC) indices. Ensuring credibility and operational reliability.||Stauning, P et al.||p-Poster|
| ||Peter Stauning|
| ||Danish Meteorological Institute|
| ||Abstract. The Polar Cap (PC) indices, PCN (North) and PCS (South) are based on polar geomagnetic observations from Thule and Vostok, respectively. The magnetic data are processed to measure the transpolar convection that may carry plasma and magnetic fields from the front of the magnetosphere to the tail region building up excess energy that subsequently could be released in substorm activity, which in turn could endanger power grids and other vital community systems. A scale for anticipated space weather effects related to PC index levels is presented.
To establish reliable space weather forecasts based on the PC indices, and also to ensure credibility of scientific analyses of solar wind-magnetosphere interactions, additional sources of data for the PC indices could be useful should the primary sources fail. In the search for alternative index sources, objective quality criteria have been established to be used for the selection among potential candidates. These criteria have been applied to existing PC index series to establish a quality scale.
In the Canadian region, the data from Resolute Bay magnetometer have passed the PC index quality tests and could provide alternative PCN indices. In Antarctica, the data from the Concordia Dome-C observatory could provide basis for alternative PCS indices.
In examples to document the usefulness of these alternative index sources it is shown that PCN indices based on local magnetometer data from Resolute Bay could have given 6 hours of early warning, of which the last 2 hours were “red alert”, up to the onset of the substorm event on 13 March 1989 that caused the power outage in Quebec. The alternative PCS indices based on data from Dome-C have disclosed corrupted Vostok-based PCS index values though most of 2011.
|24||First Measurements from the EUV and X-Ray Irradiance Sensors (EXIS) on GOES-16||Machol, J et al.||p-Poster|
| ||J. Machol[1,2], F. Eparvier, R. Viereck, T. Woods, A. Jones, M. Snow, D. Woodraska, E. Thiemann, W. McClintock, M. Anfinson|
| ||U. of Colorado CIRES; NOAA NCEI; U. of Colorado LASP; NOAA SWPC|
| ||Launched in November 2016, the NOAA GOES-16 satellite carries the Extreme Ultraviolet and X-Ray Sensors (EXIS) with new versions of the Extreme Ultraviolet Sensor (EUVS) and X-Ray Sensor (XRS) for monitoring the solar irradiance in the wavelength range that drives the thermosphere and ionosphere. The new XRS features updated technology, an increased dynamic range, and flare location capability, while continuing the longstanding historical record of solar soft X ray measurements of flare variability. The previous version of the EUVS measured broad bandpasses, whereas the new EUVS measures specific solar line emissions selected to span the range of temperatures and variability in the solar atmosphere as well as the Mg II index, allowing for the modeling of the full spectral range. In this presentation we will give an overview of the measurements, data products, and first results for the GOES-16 EXIS.|
|25||Statistical Investigation of Ionospheric Electron Density During Geomagnetic Storms Over Istanbul And Implications for GPS Communications||Erbas, B et al.||p-Poster|
| ||Bute Naz Erbaş, Zerefşan Kaymaz|
| ||Istanbul Technical University,Faculty of Aeronautics and Astronautics|
| ||In this study, the electron density variations over Istanbul (41.01°N, 28.58°E) during the magnetically active times were analyzed using Dynasonde observations. In order to perform statistical analyses, first magnetic storms and magnetospheric substorm intervals from January 2013 to December 2015 were detected using magnetic indices Dst and AE. Ionospheric parameters, such as critical frequency of F2 region (foF2), maximum electron density height (hmF2), total electron density (TEC) etc. were retrieved from Dynasonde database at Istanbul Technical University’s Upper Atmosphere and Space Weather Laboratory. To understand the behavior of electron density during the geomagnetic storms, the quiet time variations were removed and the anomalies were quantified. Results from the selected cases corresponding to the strong geomagnetic storms as well as the statistical search based on three years of data will be reported. Initial results indicate lower electron densities at noon times and higher electron densities in the late afternoon toward sunset. Distribution of the maximum and minimum differences according to the time of the day were obtained and will be discussed in terms of magnetic storm occurrences. The variations in maximum usable frequency at different incidence angles were determined during the geomagnetically active periods. The effect of the electron density variations on the GPS distance delay were calculated using L1 and L2 frequencies over our region. The results will also be compared with the simulations from the IRI and TIEGCM ionospheric models in order to interpret the variations over our region as well as to expose the differences between the models.|
|26||Vertical and oblique incidence sounder networks in the Australian region||Maher, P et al.||p-Poster|
| ||Phillip Maher, Vickal Kumar, Zahra Bouya|
| ||Australian Bureau of Meteorology - Space Weather Services|
| ||The Australian Bureau of Meteorology's Space Weather Services (SWS) operates a Vertical Incidence Sounding (VIS) ionosonde network with stations located around the Australian mainland as well as Niue Island, Cocos Island and the Australian Antarctic regions. Currently on loan to SWS is an Oblique Incidence Sounding (OIS) receiver from the Australian Defence Science and Technology Group (DSTG). The Digital Oblique Receiver System (DORS) can scan up to 9 separate oblique HF radio paths delivering high cadence rate ionograms and true height profiles. Located at SWS solar observatory in Culgoora NSW, the DORS unit provides SWS with high density inland ionospheric sample points to study such phenomena as Travelling Ionospheric Disturbances (TID). This presentation explores the benefits of combining both the VIS and OIS data for Real Time Ionospheric Model (RTIM) improvement, the validation of the OIS data via the study of ionograms from a coincident VIS sample point and the capability to detect TID and the effects on HF system performance. |
|27||Geomagnetic storm effect at mid-low-equatorial D-region ionosphere inferred using very low frequency waves ||Maurya, A et al.||p-Poster|
| ||Ajeet Kumar Maurya|
| ||Atmospheric Physics Lab, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi, India, 221005|
| ||The effects of the geomagnetic storm on the E and F-region of the ionosphere are well studied using several techniques such as GPS TEC, Ionosonde and satellite measurements. But because of the limitations in D-region probing techniques the storm effect in the D-region remains not well understood. In the present work, we examined the effect of the super geomagnetic storm of 17 March 2015 via sub-ionospherically propagating VLF signal recorded over low latitude Indian station Allahabad. We have used two VLF transmitter signal GBZ (19.6 kHz) from the Great Britten and NWC (19.8 kHz) from Australia. The transmitter-receiver great circle path (TRGCP) for Allahabad GBZ covers the mid-low latitude region whereas Allahabad NWC covers low-equatorial latitude region. The VLF amplitude measurements show a decrease compared to an average of five geomagnetically quiet days starting on 17th March (the main phase of the storm) and fully recovered on 28th March, 02 days after recovery of the geomagnetic field. The GBZ signal show more decrease (~9 dB) compare to NWC signal (~5 dB). The effects are most marked during twilight and night hours but are usually absent at noon hours. The decrease in the VLF amplitude most probably caused by the absorption of signal due to an anomalous increase in the D-region ionization associated with the storm. The pronounced effect of the geomagnetic storm on VLF signal during twilight and night hours further confirms that the ionization changes in the D-region associated with magnetic disturbances are not significant near noon hours. The delayed recovery of VLF amplitude could be of several reasons such as a change in atmospheric structure, dynamical process during storm and heat conduction from exosphere to thermosphere.|
|28||Seasonal and local time evolution of geomagnetic fluctuations over the last 100 years||Peitso, P et al.||p-Poster|
| ||Pyry Peitso[1,2], Eija Tanskanen[1,2]|
| ||Aalto University School of Electrical Engineering, Department of Electronics and Nanoengineering; Center of Excellence ReSoLVE, Magnetic unit|
| ||We will examine seasonal, solar cycle and local time evolution of geomagnetic fluctuations for the last 100 years since 1914. In order to study geomagnetic fluctuations over several tens of years we need to be able to handle simultaneously high time resolution of 1 s and data for space climate time scales. We have developed a new measure called the fractional differential rate (FDR) to determine the coverage of geomagnetic fluctuations exceeding a given threshold of magnetic fluctuations e.g. 0.20 nT/s. This new measure together with the traditionally used measures for fluctuation amplitudes i.e. magnetic field time derivatives (dH/dt) are used to study the data e.g. from Nurmijärvi, Abisco, Sodankylä and Greenland west coast. Each observatory data is handled separately, and dH/dt and FDR are computed for the entire time span by using the highest resolution of data available. The analysis of seasonal and local time evolution of magnetic fluctuations is done for the entire timeline consisting of measurements from 11 solar cycles. This is done by extrapolating the data to the lowest available time resolution and by homogenizing the entire data interval by removing secular variation and then by using the best available homogenization methods. We found out that largest magnetic field fluctuations and by far the largest coverage of fluctuations is seen at midnight for latitudes below 72 GMlat (i.e. oval) and at high noon above 72 GMlat (i.e. polar cap).|
|29||Ionospheric and thermospheric response to the 22-23 June 2015 geomagnetic storm as seen from the Swarm constellation||Astafyeva, E et al.||p-Poster|
| ||E. Astafyeva, I. Zakharenkova, E. Doornbos, J. van den IJssel|
| ||Institut de Physique du Globe de Paris, UMR CNRS 7154, 35-39 Rue Hélène Brion, Paris 75013 France; Delft University of Technology, Delft, Netherlands|
| ||It is known that the Earth’s ionosphere can change the path of radio signals, and that steep density gradients can cause severe radio scintillations and losses-of-lock. Therefore, nowadays an extensive study of the ionospheric “weather” and its forecast based on correct modeling becomes of high priority and importance.
Ionospheric alterations due to geomagnetic storms, also referred to as ionospheric storms, are known to be one of the major sources of the ionospheric perturbations. In this work, by using data from multiple instruments, we investigate ionospheric/thermospheric behavior during an intense geomagnetic storm of 22-23 June 2015. The storm started with the arrival of a coronal mass ejection at 18:37UT on 22 June 2015. With the minimum SYM-H excursion of -207 nT, this storm is so far the 2nd strongest geomagnetic storm in the current 24th solar cycle. Lasted for many hours, it provoked significant effects in the thermosphere and ionosphere on both day and night-sides. In the thermosphere, the dayside neutral mass density exceeded the quiet-time levels by 300-500%, with stronger effects in the summer hemisphere. In the ionosphere, the largest storm-time changes were observed in the night-time low-latitude topside ionosphere, led by the prompt penetration electric fields (PPEF). At the end of the main phase, the disturbance dynamo seemed to contribute as well, significantly increasing the VTEC and the electron density over the Asian region.|
|30||The solar wind driving as a regulator of ionospheric concentration dynamic in the auroral zone||Makarova, L et al.||p-Poster|
| ||Liudmila Makarova, Alexander Shirochkov|
| ||Arctic and Antarctic Research Institute|
| ||The data of recently opened wide longitudinal network of the 7 Russian digital vertical ionozondes, located in the auroral zone in longitudinal sector from 30º E till 150º E were used in this study. As one can see the observational sites cover almost half of the Northern auroral oval. It was found that electron concentration in the auroral ionosphere diminished under enhancement of the solar wind driving. The first results showed that the state of the high-latitude ionosphere is associated with the perturbation of Space Weather. It was found that during strong magnetic disturbances associated with the passage of high-speed solar wind sweats or the ejection of coronal masses, ionization on the day side of the high-latitude ionosphere decreases. In our works, we used as the index of solar wind perturbation the position of the magnetopause boundary on the day side. It turned out that as the magnetopause approaches the Earth, the electron concentration on the day side in high latitudes decreases. Investigations of long-term dependences between the ionosphere and Space Weather showed that the average annual height of the ionospheric layer maximum at the F region level varies according to the average annual values of the interplanetary magnetic field total vector B (nT) (r = 0.8).
The dynamics of the auroral ionosphere is associated not only with the structure of the magnetosphere, but also with penetrating electric fields and field-aligned currents, the distribution of which in the magnetosphere and the ionosphere depends on the parameters of the solar wind and the state of Space Weather. The mechanisms of precipitation of particles in the auroral ionosphere can be different, but all of them depend on the magnitude of the electric field of the solar wind transmitted to the magnetosphere. As an indicator of the magnitude of the electric field in our work, we used the magnetic index of the PC, which enabled us to investigate the latitude-longitude features of the distribution of the electron concentration at the level E and F of the ionosphere region based on the data of vertical ionozondes. As a result, maps of the distribution of the electron concentration are obtained depending on the perturbation of the electric field carried by the solar wind.
|31||The Met Office Atmospheric Density Service||Marsh, M et al.||p-Poster|
| ||Mike Marsh, David Jackson, Daniel Heynderickx, Eugeniu Mihnea Popescu, Ana Caramete, Vlad Constantinescu, Reuben Wright|
| ||Met Office, UK; DH Consultancy, Belgium; Institute of Space Science, Romaina; DEIMOS Space UK Ltd.|
| ||The Met Office Atmospheric Density Service provides estimates of atmospheric density, intended to support users concerned with atmospheric drag calculation. The service provides atmospheric estimates of total neutral density within the altitude range 120-1500 km, based on the pre-operational implementation of the semi-empirical model DTM2013. The service delivers three atmospheric density products: a daily density forecast up to 27-days ahead, a higher cadence 3-hourly forecast out to 3-days ahead, and a daily retrospective density estimate.
The prototype service has been developed within the ESA SSA SWE activity on “Space Weather Service Developments” (P2-SWE-II), which is focused on the development of services within the SWE/SST domain, in support of the SSA Space Weather (SWE) network. The service output will be available via the SSA SWE Portal (http://swe.ssa.esa.int) in 2018.
This activity is in development under the ESA contract No 4000116100/15/D/MRP.