Session 14 - Achievements in Magnetosphere - Ionosphere - Thermosphere coupling during geomagnetic storms and magnetospheric substorms
Tommaso Alberti (INAF), Paola De Michelis (INGV), Anna Belehaki (NOA)
Thursday 21/11, 17:15-18:30
Friday 22/11, 11:15-12:30 & 14:00-15:15
Geomagnetic and ionospheric storms and magnetospheric substorms are the major complex disturbances of Space Weather. Their triggering mechanisms are known to be multifaceted phenomena, originating from the solar corona, propagating through the interplanetary space, and affecting the circumterrestrial environment, e.g., the magnetosphere, the ionosphere, and the thermosphere. Sometime they can also affect the Earth’s surface generating electrical currents, which are capable of travelling into the power grid, potentially damaging transformers and causing regional power shortages or even blackouts. In the past several studies have been devoted to the understanding of the response of the Earth’s magnetosphere – ionosphere system to the changes of the solar wind and interplanetary conditions and to the study of geomagnetic storms, substorms and to the coincident thermospheric storms. Several data have been used to characterize these phenomena coming from different satellites and ground-based observatories, as well as, also new tools and methods of analysis have been proposed to quantify and characterise the dynamics of these complex phenomena.
This session aims at discussing the most recent results in the characterisation of the complex solar wind – magnetosphere – ionosphere - thermosphere coupling and dynamics in response to interplanetary condition changes, both on theoretical and observational points of view, and in providing an overview of the relevance of data analysis tools, novel conceptual studies, dynamical systems approaches and methods in the investigation and modelling of relevant phenomena. Feedback from different methods and models relevant to the investigation and characterization of physical processes in the coupled magnetospheric-ionospheric-thermospheric system is also encouraged.
Thursday November 21, 17:15 - 18:30, Mosane 789
Friday November 22, 11:15 - 12:30, Mosane 789
Friday November 22, 14:00 - 15:15, Mosane 789Click here to toggle abstract display in the schedule
Talks : Time scheduleThursday November 21, 17:15 - 18:30, Mosane 789
Friday November 22, 11:15 - 12:30, Mosane 789
|17:15||Plasma wave properties and storm-substorm relationship as reflections of the coupled solar wind-magnetosphere-ionosphere dynamic system||Daglis, I et al.||Invited Oral|
| ||Ioannis A. Daglis[1,2], Georgios Balasis|
| || Department of Physics, National and Kapodistrian University of Athens, Greece;  Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, Greece|
| ||We present a selective overview of studies using observations by ongoing space missions (such as Van Allen Probes, Swarm, etc) and ground facilities on the growth and propagation properties of various plasma waves, which are critical for the ring current and radiation belt dynamics. We discuss their implications on our understanding of the role of plasma waves in solar wind – magnetosphere – ionosphere coupling and in space weather forecasting. Furthermore, we address the dynamical relationship between geomagnetic storms and magnetospheric substorms - one of the most controversial issues of space research. We report on the possible existence of a driver-response relationship between storms and substorms, which is a reflection of dynamic processes within the coupled solar wind-magnetosphere-ionosphere system.|
|17:45||Comparison of the Plasma Disturbances in the Ionosphere Registered by DEMETER and Swarm Satellites during Geomagnetic and Thunderstorms||Blecki, J et al.||Oral|
| ||Jan Błęcki, Jan Słomiński , Roman Wronowski, Ewa Słomińska, Rafał Iwański, Roger Haagmans and Michel Parrot|
| || Space Research Centre PAS, Warsaw, Poland,  OBSEE, Warsaw, Poland ,  IMWM Cracow, Poland,  ESTEC Noordwijk, Netherlands,  Michel Parrot, LPC2E Orleans, France.|
| ||The observation of the magnetic field, electron density and temperature variations in Ultra and Extremely Low Frequency (ULF/ELF) registered by Swarm satellite in the ionosphere over the thunderstorm areas and during geomagnetic storms will be presented. 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 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 of the electron density and temperature disturbances, fluxes of the energetic electrons as well as ELF/VLF emissions over strong thunderstorm areas done by DEMETER and Swarm satellites will be given in the presentation. These registrations will be compared with the effects seen in the ionosphere during strong magnetic storms.
Acknowledgments. This work was supported by grant NCN 2017/27/B/ST10/02285 and ESA contract No:4000112769/14/NL/FF/gp. |
|18:00||Magnetopause position and solar wind pressure: Going beyond a statistical relation||De keyser, J et al.||Oral|
| ||Johan De Keyser, Mario Bandic, Giuli Verbanac|
| ||(1) Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Ringlaan 3, B-1180 Brussels, Belgium, (2) University of Zagreb, Croatia|
| ||The stand-off distance of the nose of the magnetopause is determined by pressure balance between the solar wind and the terrestrial magnetosphere. Since the solar wind pressure (mostly the ram pressure) and – to a lesser extent – the magnetospheric pressure vary, the magnetopause is in constant motion. In the past, several authors have derived a statistical relationship between solar wind ram pressure and magnetopause position obtained from a large number of identified magnetopause crossings at scattered moments in time. The present contribution goes beyond such a statistical approach and will present examples where a direct relation between magnetopause and solar wind pressure is identified during a continuous time interval. This is possible thanks to long-duration tracking of the magnetopause position with empirical reconstruction techniques that exploit Cluster observations. Both statistical correlations and continuous relations can be used for space weather prediction. We highlight the fundamental differences between both approaches for determining magnetospheric response to the solar wind driver.|
|18:15||Physics-based validation of global MHD models||Jorgensen, T et al.||Oral|
| ||Therese Moretto, Michael Hesse, Masha Kutzentsove, Lutz Rastaetter, Susanne Vennerstrom, Paul Tenfjord
| || University of Bergen
 NASA GSFC
 DTU Space
| ||Global MHD models constitute a unique tool for developing a forecast capability for space weather effects in the near-Earth space environment. In combination with modules for the ionosphere, inner magnetosphere, and radiation belts they offer a comprehensive, physical description of the morphology and dynamics of the coupled solar wind-magnetosphere-ionosphere system. Several such solutions have been developed over the last decades. Their further advancement is key to improving space weather forecasting accuracy and lead times. It is unlikely that skill score comparisons alone will provide sufficient guidance for this development. Scientific evaluations and comparisons are needed in addition.
Here we present the results of carrying out a physics-based evaluation and comparison of four different global MHD models available for runs-on-request at the Community Coordinated Modeling Center (CCMC). One condition that model simulations should meet, in the absence of parallel electric fields, is that ionospheric footprints of closed field-lines are at the same potential in the two hemispheres. How well this condition is met by global MHD models relates to understanding how well models represent the ionospheric potential and symmetries or asymmetries thereof. Dipole tilt and a significant east-west component in the interplanetary magnetic field are both examples of effects that create complex potential patterns in the ionosphere with large differences and asymmetries between the northern and southern hemispheres. The degree to which these are reproduced correctly in the models is an important open question. We report here on an investigation of the extent and comparison of the equal potential-condition between the four global MHD models and discuss its possible implication for answering this larger question.
Friday November 22, 14:00 - 15:15, Mosane 789
|11:15||SuperDARN in a Space Weather Perspective||Marcucci, M et al.||Invited Oral|
| ||Maria Federica Marcucci|
| ||The Super Dual Auroral Radar Network (SuperDARN) is an international network of more than 30 HF radars
whose fields of view cover the ionosphere for the majority of the area from the poles to the mid latitudes
of the Northern and Southern Hemisphere. The SuperDARN radars operate continuously
and important geospace parameters can be derived from their observations,
among which the most important is probably the F region ionospheric plasma flows dynamics.
Such observations are of relevance in the space weather context. In fact, SuperDARN observations can be used
to gage the forecasting models outputs and so to improve their accuracy.
As a further example, attention has recently been put on the use of SuperDARN data to monitor
the ionospheric effects of space weather events.
The SuperDARN relevance in the frame of Space Weather will be the subject of this presentation.|
|11:45||SuperDARN observations during geomagnetic storms, geomagnetically active times and enhanced solar wind driving||Walach, M et al.||Oral|
| ||Maria-Theresia Walach, Adrian Grocott|
| || Lancaster University, UK|
| ||The Super Dual Auroral Radar Network (SuperDARN) has in recent years been expanded to lower latitudes to observe ionospheric flows from the pole to 40 degrees magnetic latitude. This enables us to study extreme space weather events, such as geomagnetic storms, which are a global phenomenon, on a large scale. We study the backscatter observations from the SuperDARN radars during all geomagnetic storm phases from the most recent solar cycle (2010-2016) and compare them to other active times to understand radar backscatter and ionospheric convection characteristics during extreme conditions and to discern differences specific to geomagnetic storms and other geomagnetically active times. We show that there are clear differences in the number of measurements the radars make, the maximum flow speeds observed and the locations where they are observed during the initial, main and recovery phases of geomagnetic storms. We show that these differences are linked to different levels of solar wind driving. We also show that when studying ionospheric convection during geomagnetically active times, it is crucial to consider data at mid-latitudes, as we find that during 19% of storm-time the equatorial boundary of the high-latitude ionospheric convection is located below 50 degrees of magnetic latitude.|
|12:00||Trapped Population Response During Geomagnetic Auroral Super Storms||Matar, J et al.||Oral|
| ||Jessy Matar, Benoit Hubert, and Zhonghua Yao|
| ||Laboratory of Planetary and Atmospheric Physics, University of Liège, Liege, Belgium|
| ||The radiation belts have a more pronounced response to global disturbances of the magnetospheric system during geomagnetic super storms. Those are characterized as prolonged periods of high magnetic activity and identified by several indices, such as the Dst index. The magnetospheric current system is enhanced during storms and causes consequential variations in the Earth’s magnetic field, thus producing a surface electric field. We study two super storms, on August 2000 and April 2001 for which the distribution of the helium ion (He+) population in the plasmasphere defined as the torus of cold dense plasma surrounding the Earth in the inner magnetosphere is imaged using the extreme ultraviolet (EUV) instrument on board the NASA-IMAGE spacecraft. We aim to analyze the variation of the He+ density in the plasmasphere during those storms and we search for enhancements in the He+ density budget. We determine the plasmapause location and map it to ionospheric altitude along the magnetic field lines. The ionospheric context is then studied in terms of auroral precipitation using FUV imaging of the electron and proton aurora at higher latitude. The electric field is also considered using measurements of the ionospheric convection from the SuperDARN radar network and using DMSP crossings of that region.|
|12:15||Magnetic local time asymmetries in electron and proton precipitation with and without substorm activity||Yakovchuk, O et al.||Oral|
| ||Olesya Yakovchuk, Jan Maik Wissing|
| ||Institute of Environmental Systems Research, Osnabrueck, Germany, Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Moscow, Russia|
| ||The magnetic local time (MLT) dependence of electron (0.15--300~keV) and proton (0.15--6900~keV) precipitation into the atmosphere based on National Oceanic and Atmospheric Administration POES and METOP satellites data during 2001--2008 was described. Using modified APEX coordinates the influence of particle energy, substorm activity and geomagnetic disturbance on the MLT flux distribution was statistically analysed.
Some of the findings are:
a) MLT flux differences of up to 1:$2^5$ have been localized inside the auroral oval.
b) MLT dependence can be assigned to different particle sources and energy-specific drifts.
c) The maximum flux asymmetry ratio depends on particle energy, but not necessarily on geomagnetic disturbance. For protons it is invariant with Kp, for electrons the dependence varies with Kp and kinetic energy defines how.
c) Substorms mostly increase particle precipitation in the night-sector by about factor 2--4 but can also reduce it in the day-sector.
Finally we have a look at MLT-dependent trapped particle flux in the plasmasphere, which shows vast and abstract MLT differences.|
|14:00||Statistical quantification of extreme space weather events across multiple solar cycles: the Carrington event in context||Chapman, S et al.||Oral|
| ||S. C. Chapman, R. B. Horne, N. W. Watkins[1,3,4]|
| || Centre for Fusion, Space and Astrophysics, Physics Dept., University of Warwick, Coventry CV4 7AL, UK,  British Antarctic Survey, UK,  Centre for the Analysis of Time Series, LSE, London, UK,  STEM, Open University, Milton Keynes, UK|
| ||Each of the sun’s roughly 11-year cycles has a different maximum level and duration which is reflected in the overall level of space weather activity at earth. Long term observations are now available over multiple solar cycles, so that the space climate effects of the variability between each unique solar cycle can be investigated statistically [1,2,3]. The occurrence rate of large events, and the power level of fluctuations both correlate with overall solar activity, albeit in a non-trivial manner. Over the last five solar cycles we have both solar wind in-situ monitors and indices for geomagnetic response. Solar (F10.7), solar wind (dynamic pressure, convection electric field) and magnetospheric response (AE, Dst and their SuperMAG counterparts) parameters vary with the different activity levels of each solar cycle maximum but we have found  that certain properties of the statistical distribution tail of larger observations are invariant from one solar maximum to the next. Characterizing observations of the past heliospheric climate in this manner may assist prediction of that of the next solar cycle.
To study the most extreme events we analyse the aa index which tracks the geomagnetic response at the earth's surface over the last 14 solar cycles. We find  that the largest 1% and 0.1 % of aa values (the 99th and 99.9 th percentiles) all occurred within a well defined region of aa and sunspot number and that super-storms generally correspond to the 99.9 aa percentile being well above 200nT, a value that was not reached during the last anomalously weak solar cycle. The Carrington super-storm lies within this region, consistent with the same underlying properties as other historical super-storms. Since future solar cycles are predicted to be weaker than in the past, our results suggest that the risk of a severe space weather event may also be lowered. This points towards the need for quantification of these rare extreme events and their impact.
 E. Tindale, S. C. Chapman, Solar cycle variation of the statistical distribution of the solar wind ε parameter and its constituent variables, GRL DOI: 10.1002. 2016GL068920 (2016)
 E. Tindale, S. C. Chapman, Solar wind plasma parameter variability across solar cycles 23 and 24: from turbulence to extremes, J. Geophys. Res., DOI: 10.1002/2017JA024412 (2017)
 E. Tindale, S. C. Chapman, N. R. Moloney, and N.W. Watkins, The dependence of solar wind burst size on burst duration and its invariance across solar cycles 23 and 24, JGR, (2018) DOI: 10.1029/2018JA025740
 S. C. Chapman, N. W. Watkins, E. Tindale, Reproducible aspects of the climate of space weather over the last five solar cycles, Space Weather, DOI:10.1029/2018SW001884 (2018)
 S. C. Chapman, R. B. Horne, N. W. Watkins, Solar cycle dependence of extreme space weather, Space Weather, submitted (2019)
|14:15||Investigating dynamical complexity at Swarm altitudes using information-theoretic measures||Balasis, G et al.||Oral|
| ||Georgios Balasis, Constantinos Papadimitriou, Adamantia-Zoe Boutsi, Omiros Giannakis, Anastasios Anastasiadis, Ioannis A. Daglis, Paola De Michelis, Giuseppe Consolini|
| ||National Observatory of Athens, National and Kapodistrian University of Athens, Istituto Nazionale Geofisica e Vulcanologia, Istituto Nazionale di Astrofisica|
| ||Recently, many novel concepts originated in dynamical systems or information theory have been developed, partly motivated by specific research questions linked to geosciences, and found a variety of different applications. This continuously extending toolbox of nonlinear time series analysis highlights the importance of the dynamical complexity to understand the behavior of the complex solar wind – magnetosphere – ionosphere - thermosphere coupling system and its components. Here, we propose to apply such new approaches, mainly a series of entropy methods to the time series of the Earth's magnetic field measured by the Swarm constellation. Swarm is an ESA mission launched on November 22, 2013, comprising three satellites at low Earth polar orbits. The mission delivers data that provide new insight into the Earth's system by improving our understanding of the Earth's interior as well as the near-Earth electromagnetic environment. We show successful applications of methods originated in information theory to quantitatively studying complexity in the dynamical response of the topside ionosphere, at Swarm altitudes, focusing on the most intense magnetic storms of the present solar cycle.|
|14:30||What is happening with the Sun – and ionospheric response||Lastovicka, J et al.||Oral|
| ||Jan Lastovicka|
| ||Institute of Atmospheric Physics CAS, Prague, Czech Republic. |
| ||Some recent results indicate that the relationships among solar activity indices and their relation to ionospheric parameters have been changing from the solar cycle 23. Not only the solar activity is now much lower than in solar cycles 18-22, also the sunspot formation fraction parameter dropped down substantially, the relationship between F10.7 and sunspot numbers changed, and some problems in relation of foE and foF2 to F10.7 were detected. Here we check stability of relationship between F10.7 and Mg-II solar indices and the solar H-Lyman-alpha flux, and also stability of their relationship with foE and foF2 for a few selected European high-data-quality stations. Some noticeable changes have been observed.|
|14:45||Solar and geomagnetic activity impact on thermospheric density during ESA’s mission GOCE||Berrilli, F et al.||Oral|
| ||Francesco Berrilli, Alberto Bigazzi, Carlo Cauli, Dario Del Moro, Luca Giovannelli|
| ||(1) Dipartimento di Fisica, Università di Roma Tor Vergata, I-00133, Roma, Italy|
| ||The GOCE satellite measurements of the thermosphere density, derived from the high-precision accelerometers on board at a mean altitude of 254 km, represents a unique low-altitude dataset to study the coupling between solar and geomagnetic activity and thermosphere physical properties.
More in detail, the impact of solar and geomagnetic activity on thermosphere density during ESA’s gravity mission GOCE has been investigated using different solar and geomagnetic indices. The analysed period (17 March, 2009 - 11 November, 2013) corresponds to the rising phase of solar cycle 24.
The temporal behavior of Ap geomagnetic index and solar activity indices, i.e. the F10.7 flux and the Mg II
core-to-wing ratio, have been examined and their correlations with GOCE thermospheric density studied.
Then, solar indices have been decomposed into a set of modes, i.e. the intrinsic mode functions (IMFs), through the Empirical Mode Decomposition (EMD), a technique best suited in analysing non-stationary and non-periodic time signals.
After the decomposition, certain subsets of of IMFs from the solar and geomagnetic indices and thermospheric
density have been reconstructed and compared with the original GOCE dataset. The results suggest the relevance
of using the Mg II and Ap indices and EMD IMFs in describing the solar-magnetosphere-thermosphere coupling and reconstruct the
|15:00||Asymmetries of ground magnetic disturbances at mid-latitudes during extreme geomagnetic storms and their relevance depending on their intensity||Saiz, E et al.||Oral|
| ||Elena Saiz, Consuelo Cid, Antonio Guerrero|
| ||`1] Space Weather Group (SWE), Physics and Mathematics Department, University of Alcalá (UAH), Spain|
| ||Mid latitudes have been considered less dangerous than high or even equatorial ones from the point of view of space weather hazards. The reason is that they are far from the current systems that produce the most relevant disturbances of the ground magnetic field during geomagnetic storms: the electrojects and the ring current. We study the significance of these and other currents during the extreme events (Dst < -200 nT and AL < -2000 nT) occurred in the period 1998-2017. For this goal, we analyze the ground magnetic records from six observatories widely spread in longitude and located into a narrow mid-latitude range (35-45º magnetic latitude). The average of the magnetic disturbances of the six locations and the local deflections respect to the average are computed. The MLT distribution of these deflections allow us to distinguish several asymmetries (dawn-dusk, morning-afternoon and day-night) which are intensity dependent. The results obtained allow us to deduce which current system is the prevalent one at those intensity ranges. For intensities greater than 70% the average of the magnetic disturbance, the results show that only the day-night asymmetry appears, pointing out that the current system responsible for these extreme disturbances is the large-scale R1/R2 FACs, even at mid-latitudes. |
|1||Global plasmapause characteristics based on satellite data and numerical simulations||Verbanac, G et al.||p-Poster|
| ||Giuli Verbanac, Mario Bandić, Viviane Pierrard|
| ||Faculty of Science, University of Zagreb, Croatia. Astronomical Observatory Zagreb, Croatia. Royal Belgian Institute for Space Aeronomy (Space Physics and STCE), Brussels, Belgium|
| ||The novel missions, IMAGE, CLUSTER, and THEMIS have given a new insight into the plasmaspheric dynamics and have revealed different unexpected plasmapause structures (e.g., plumes, notches, and shoulders) that are mainly formed during the periods of enhanced geomagnetic activities.
Generally, great progress has been made in understanding the plasmaspheric dynamic and plasmapause structure formation. Nevertheless, the basic questions related to the global plasmapause behavior, as MLT of the plasmapause formation and propagation characteristics of the main plasmapause have still remained unclear.
By applying the cross-correlation analysis to the plasmapause databases based on CLUSTER, CRRES and THEMIS satellites, and both solar wind parameters and geomagnetic indices we derived the most important physical effects on plasmapause formation and propagation.
The derived plasmapause characteristics are compared with the numerical simulations based on interchange instability mechanism.
The obtained results will be discussed and the implication for space weather will be emphasized.
|2||St. Patrick’s Day Storm: an analysis of the geomagnetic field fluctuations - INTERACTIVE POSTER PRESENTATION, Thursday 21/11, 15:45-16:15 ||Santarelli, L et al.||p-Poster|
| ||Lucia Santarelli[1,2], Paola De Michelis, Giuseppe Consolini|
| || Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy,  Università degli Studi dell’Aquila, L’Aquila, Italy,  INAF-Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy|
| ||We analyze minute values of ground-based geomagnetic fluctuations at about 50 observatories located at throughout the Northern Hemisphere during the St.Patrick's storm in March 2015. The application of the Empirical Mode Decomposition method, which is well suitable for the analysis of signals resulting from non-linear and non-stationary processes, it allows the separation of fluctuations on different time scales (short<200 min, and long>200 min). The different contribution to the source signal of short and long fluctuations, associated with different magnetospheric processes, is analyzed as a function of latitude during the geomagnetic storm. The weight of the signal related to the fluctuations on a short time scale shows a dependence on the latitude and geomagnetic activity level.|
|3||Creation & Classification of Magnetosheath Jet Database using Magnetospheric Multiscale (MMS) mission.||Raptis, S et al.||p-Poster|
| ||Savvas Raptis, Tomas Karlsson, Per Arne Lennart Lindqvist|
| ||Space and Plasma Physics, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Sweden|
| ||Magnetosheath jets are flows that manifest as localized, large amplitude and transient increases of dynamic pressure. They are fast plasma flows generated after solar wind interacts with the bow shock, making them a valuable component, connecting solar wind and magnetospheric environments. Jets are associated with several space weather phenomena such as, radiation belts, ionospheric flow enhancements, magnetic reconnection and auroral features.
In this work, we present a database of several thousands of magnetosheath jets along with various of their characteristics. We organize the dataset into several subsets depending on their properties, while each jet holds information regarding general properties (position, duration etc.), plasma moments (density, velocity, temperature etc.) and field (electric & magnetic) measurements as observed by MMS. Each jet was also associated with solar wind plasma parameters from High Resolution OMNI (HRO) database.
Finally, we classify the jets into different classes depending on the angle between the Interplanetary Magnetic Field (IMF) and the bow shock’s normal vector $(θ_Bn)$. This creates subsets of jets found in the Quasi-parallel magnetosheath $(θ_Bn<45°)$ and in the Quasi-perpendicular $(θ_Bn>45°)$.
The dataset has been derived by using in-situ measurements of various plasma quantities and magnetosheath magnetic and electric field as measured by the Magnetospheric Multiscale (MMS) mission during 09/2015 – 06/2019.
The importance of the presented magnetosheath database is directly relevant to space weather research. Magnetosheath jets have been associated with several geoeffective phenomena and a lot of insight can be achieved through associating specific events with other space and solar phenomena such as CMEs, solar wind flows, ionospheric flow enhancements and geomagnetic storms.
|4||A Study of Ionospheric Turbulence in the Polar Regions by Swarm constellation - INTERACTIVE POSTER PRESENTATION, Thursday 21/11, 15:15-15:45 (no printed poster)||De michelis, P et al.||p-Poster|
| ||De Michelis Paola, Consolini Giuseppe, Balasis Georgios, and INTENS team(*)|
| ||Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy, INAF-Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy, Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, Greece|
| ||Turbulence and small-scale fluctuations of magnetic field and plasma parameters in the polar ionosphere are expected to play a relevant role in the course of geomagnetic storms and substorms. In the framework of “EO Science for Society Permanently Open Call” the project “Characterization of IoNospheric TurbulENce level by Swarm constellation (INTENS)” is a study recently approved by ESA, which aims to investigate the nature of geomagnetic field and plasma parameters (i.e., electron density and temperature) fluctuations, as well as their scaling features during different geomagnetic disturbance conditions, to unveil the role played by the magnetohydrodynamic (MHD) turbulence on the ionospheric environment in creating multi-scale plasma structures and plasma inhomogeneity. In this work we provide a detailed study of the character of the dynamical changes of the scaling features of the electron density and geomagnetic field fluctuations in order to obtain information about the turbulent nature of the ionospheric plasma during typical geomagnetic storms. In particular, the formation of plasma inhomogeneities as indicated by the index of the ionospheric rate of change of electron density (RODI) and the passive scalar nature of electron density fluctuations is investigated. The relevance of these features in the framework of Space Weather studies is discussed.
(*) The members of the INTENS team are: A. Anastasiadis, A.Z. Boutsi, I. Coco, I. A. Daglis, F. Giannattasio, O. Giannakis, M. F. Marcucci, C. Papadimitriou, S. Pau, M. Pezzopane, A. Pignalberi, R. Tozzi and G. Vasalos|
|5||STEVE phenomenon related subauroral aurora or aurora-like luminous ionospheric structures – relevant structures, characteristics and correlations with geomagnetic storms derived from a citizen science based data package||Hunnekuhl, M et al.||p-Poster|
| ||Michael Hunnekuhl, Elizabeth A. MacDonald, Ben Swanson, Michael Theusner, James Stone, Alexei Chernenkoff, Stephen Voss, Jonathan Esling, Will Standring|
| || Eichenweg 15, 30989 Gehrden, Germany,  NASA Goddard Space Flight Center, Greenbelt, MD, US,  Aurora Australis Tasmania Facebook group,  Am Knill 29a, 22147 Hamburg, Germany,  Alberta Aurora Chasers Facebook group, Alberta, Canada,  Administrator of the Aurora Australis Facebook group, New Zealand,  Tasmanian artist and photographer, Tasmania, Australia|
| ||Since 2015/16 the STEVE phenomenon has attracted much attention but many details of this phenomenon are still unknown. An analysis of freely accessible but wide spread citizen science data, collected by hundreds of enthusiastic amateur aurora observers worldwide, mainly posted in social media groups, can strongly support the research on the STEVE phenomenon, if combined with other data from these sources or with standard space science data like geomagnetic or in-situ satellite data. An event list for amateur aurora observer observations of STEVE phenomenon related subauroral aurora or aurora-like luminous ionospheric structures has been prepared in a non-funded volunteer project. Listed observations have been combined with geomagnetic data for all 120 days for which observations are listed not only with date but also with time. Main findings derived from a statistical analysis of geomagnetic storm related parameters combined with observations are presented and discussed as well as the yearly and monthly frequency distributions and quasi-simultaneous observations from the Northern and Southern Hemisphere identified with the help of the event list. Based on the analyzed observations a phenomenological based classification scheme is prepared for STEVE phenomenon related structures and extended to other types of night-time subauroral structures extensively described in the literature with the aim to improve amateur observer classifications thus giving scientist a better starting point for a topic-focused analysis of amateur aurora observer data. STEVE phenomenon related structures show a variety of substructures. Types that are currently not mentioned in the scientific literature have been identified and are presented. Because of the more than 670 single observations listed in the event list quasi-simultaneous observations from different locations could be identified and combined to calculate altitudes for specific STEVE phenomenon related substructures as well as their drift speeds using a 3D triangulation algorithm developed for this purpose.|
|6||Comparison of FPI-Oukaimeden data with thermospheric models: GITM and TIE-GCM||Abdeladim, E et al.||p-Poster|
| || Abdeladim El fakhiri  , Aziza Bounhir |
| ||Oukaïmeden Observatory, High Energy Physics and Astrophysics Laboratory, FSSM, Cadi Ayyad University, Marrakesh, Morocco|
| ||GITM (Global Ionosphere Thermosphere Model) and TIEGCM (Thermosphere Ionosphere Electrodynamics General Circulation Model) are two different models of the thermosphere and ionosphere layers. The two models solves the three-dimensional momentum, energy and continuity equations for neutral and ion species at each time step, but there are some differences between these models. TIEGCM is a hydrostatic model using a pressure grid, while, the GITM one does not assume a hydrostatic solution, and it uses an altitude-based grid. In our study, we compare these models with temperature, meridional and zonal components of the themospheric winds measured with a Fabry-Perrot interferometer (FPI) over Oukaimden observatory at Morocco (31.21°N, -7.86°E). The FPI uses the 630.0 nm night time airglow located approximately at 250 km altitude. The measurements span from 2014 to 2016. Based on our preliminary observations, we conclude that GITM is closer to the FPI-Oukaimeden data than the TIEGCM one.|
|7||Detecting magnetospheric and ionospheric current systems patterns from Swarm observations - INTERACTIVE POSTER PRESENTATION, Thursday, 16:15-16:45 (no printed poster)||Alberti, T et al.||p-Poster|
| ||Tommaso Alberti, Fabio Giannattasio, Paola De Michelis, Giuseppe Consolini|
| ||INAF-Istituto di Astrofisica e Planetologia Spaziali, via del Fosso del Cavaliere 100, 00133 Roma, Italy, Istituto Nazionale di Geofisica e Vulcanologia, via di Vigna Murata 605, 00143 Roma, Italy|
| ||Spatial patterns embedded in 2-D signals can be investigated by using different linear and nonlinear analysis methods operating in both time and frequency domain. Generally, linear decomposition methods, like the empirical orthogonal function (EOF) analysis, are based on fixed basis functions typically found by computing the eigenvectors of the covariance matrix of the data set. A different method, the multivariate empirical mode decomposition method (MEMD), which is an extension of the empirical mode decomposition method, allows to analyse multivariate patterns by extracting intrinsic spatial components with different characteristic scales without any a priori assumptions on linearity and stationarity conditions, through a self-adaptive process.
Here, we apply the MEMD method to characterize spatial patterns of the external component of the geomagnetic field as a function of geomagnetic activity level recorded by Swarm constellation. We show that the MEMD method well reproduces the structures of the geomagnetic field of external origin during quiet and active periods by using a few modes associated with realistic equivalent currents responsible for the recorded magnetic field variations. This study is an example of the potential of the MEMD method that can be used to give new insights into the analysis of the different sources responsible of the geomagnetic field of external origin, separating the ionospheric contributions from both the magnetospheric ones.|
|8||Spatio-temporal scale features of field-aligned currents in polar ionosphere||Consolini, G et al.||p-Poster|
| ||G. Consolini, P. De Michelis, T. Alberti, R. Tozzi, I. Coco and F. Giannattasio|
| ||INAF-Istituto di Astrofisica e Planetologia Spaziali, 00133 Rome, Italy, Istituto Nazionale di Geofisica e Vulcanologia, 00143 Rome, Italy|
| ||The fine structure of Field-Aligned Currents (FAC) in the high latitude ionospheric is investigated using Swarm Level-2 (L2-FAC) single-spacecraft product [Ritter et al., 2013] and magnetic field measurements by ESA Swarm constellation. In particular, we investigate the statistical and scaling features of the FAC at the highest available resolution, comparing the results with the character of magnetic field fluctuations. The small scale feature of FACs the occurrence of current filamentation is discussed in relationship with the non-Gaussian character of magnetic field fluctuations.
This work is a part of the ESA-INTENS project|
|9||Far ultraviolet observations of aurora, thermosphere and ionosphere response to geomagnetic storms||Zhang, Y et al.||p-Poster|
| ||Yongliang Zhang, Larry Paxton, Robert Schaefer |
| || The Johns Hopkins University Applied Physics Laboratory|
| ||Far ultraviolet spectrographic (FUV) imagers on TIMED and DMSP satellites provide opportunities to monitor many geospace variations during geomagnetic storms, such as aurora, thermospheric density, composition and temperature, as well as ionospheric density. We will show examples and discuss physical processes associated with the storm-time variations, such as EMIC waves and ring current aurora, high latitude K-H instability and polar rain auroral structures, O/N2 depletion and enhancement due to heating and circulation, neutral temperature enhancement, as well traveling atmospheric and ionospheric disturbances. A FUV imager serves as a multiple purpose detector of geospace weather. |
|10||Extension of the Met Office Unified Model into the Thermosphere||Griffin, D et al.||p-Poster|
| ||Daniel Griffin , Matthew Griffith , David Jackson |
| || The Met Office, UK,  The University of Bath, UK|
| ||The Met Office is contributing to the SWAMI (Space Weather Atmosphere Model and Indices) Horizon 2020 project by providing an extended version of its Unified Model (UM) that can be merged with the Drag Temperature Model (DTM) for the thermosphere. This poster covers the development of the vertical extension of the UM and the implementation of vertical molecular viscosity and diffusion in the dynamical core.
With a suitable chemistry scheme not yet available, a realistic basic state was set up whereby the radiation scheme may be supplemented by a nudging to the climatology in the mesosphere and lower thermosphere region. The NLTE (non-Local Thermodynamic Equilibrium) radiation scheme has also been developed to give more realistic heating rates in the thermosphere. Together, these have led to more stable, accurate simulations that have enabled us to test the model with the top boundaries set at different altitudes (up to 135km), different vertical and horizontal resolutions, and different sponge layer strengths. We describe the results of these sensitivity experiments here.
We aim to further extend the UM up to 150km – 170km, and here show initial results with a 135km lid. At these higher altitudes, we need the real physical process of vertical molecular viscosity and diffusion to realistically damp vertically propagating model waves. Vertical molecular viscosity and diffusion becomes a significant damping mechanism above 130km, and may be a better alternative to the artificial “sponge layer” that has been applied near the UM upper boundary to date. Progress on this work is outlined here.|
|11||Development of Radiation Schemes for the Extended Unified Model||Jackson, D et al.||p-Poster|
| ||David Jackson, James Manners, Dan Griffin|
| || Met Office, Exeter, UK|
| ||A goal of Met Office space weather research is to develop an operational coupled Sun to Earth model forecast system, including a model spanning the Earth’s surface to the thermosphere. The first step is to extend the Met Office Unified Model (UM) from its current upper boundary near 85 km to an upper boundary near 150 km. This work is also an important part of the EU project SWAMI (Space Weather Atmosphere Model and Indices).
We focus on the changes to the representation of radiative transfer in the UM to make the model fit for purpose in the mesosphere and lower thermosphere (MLT). The existing UM radiation scheme does not represent non-local thermodynamic equilibrium (NLTE), which is needed for accurate heating rates at MLT altitudes. Here, we describe work to replace pre-existing heating rates with NLTE heating rates from the Fomichev scheme at such altitudes.
The UM scheme does not address radiative transfer from wavelengths less than 200 nm. This approach is acceptable in the lower atmosphere where these wavelengths do not penetrate, but in the MLT shorter wavelengths in the Extreme Ultraviolet (EUV) and Far Ultraviolet (FUV) also need to be included. We describe work to extend absorption calculations to these wavelengths, using the correlated-k approach to ensure accuracy while maintaining computational speed. The FUV / EUV actinic fluxes derived from two-stream calculations are used to calculate photolysis rates in order to drive the exothermic chemical reactions responsible for the large increases of temperature with altitude in the MLT.
|12||Relationship between thermospheric NO infrared emission and both solar wind parameters and geomagnetic indices within the period from 25 January 2005 to 5 May 2005||Verbanac, G et al.||p-Poster|
| ||Giuliana Verbanac, Ljiljana Ivanković, Mario Bandić|
| || Department of Geophysics, Faculty of science, University of Zagreb, Croatia, University of Applied Sciences Velika Gorica, Zagreb,Croatia, Astronimical Observatory Zagreb, Croatia|
| ||We investigate thermospheric responses to high‐speed solar wind streams (HSS) within the period from 25 January 2005 to 5 May 2005 (day-of-year, DOY = 25−125) .
This time span in the declining phase of the solar cycle No. 23 is selected because it is characterized by three long-lived equatorial coronal holes at the Sun separated in longitude by ≈120°. These coronal holes were sources of recurrent high‐speed streams that caused geospheric storms.
We used the volume emission rates from thermospheric nitric oxide (NO) obtained with SABER instrument on board TIMED which are then vertically integrated and averaged per 6 latitude bins to obtain zonal average fluxes. The analysis is based on two data resolutions: 1 hour and 6 hours.
Following parameters are used: solar wind parameters B, BV, BsV (B-interplanetary magnetic field,V-solar wind velocity, Bs southward component of the interplanetary magnetic field Bz component in GSM coordinate system), Newell function that takes into account different physical processes related to the magnetospheric activity, and geomagnetic indices Dst and AE. For each latitudinal bin the cross-correlation between the infrared NO emission and both solar wind parameters and geomagnetic indices is performed.
Results show: the strongest/weakest response to HSS is observed at high/low latitudes; maximal cross-correlation is obtained between Newell function and NO emission and between geomagnetic indices and NO emission; time of thermospheric response is estimated to be between 6 h and 15 h
depending on the investigated parameters and latitudinal bins.|
|13||Substorm triggering by magnetosheath jets during northward and radial IMF - INTERACTIVE POSTER PRESENTATION, Thursday 21/11, 15:45-16:15 (no printed poster)||Nykyri, K et al.||p-Poster|
| ||K. Nykyri, M. Bengtson[1,2], V. Angelopoulos, Y. Nishimura, S. Wing, X. Ma|
| || Embry-Riddle Aeronautical University,  University of Colorado Boulder, , University of California, Los Angeles,  Boston University,  Applied Physics Laboratory, John Hopkins|
| ||The substorm onset can cause significant enhancement of Total Electron Content scintillations in the ionosphere, which can produce positioning errors for GNSS and GPS based navigation systems. We discuss multi-spacecraft and ground-based observations of the 25 December 2015 substorm onset at 08:17 UT during northward interplanetary magnetic field (IMF) while magnetosheath contained several intervals of negative Bz. A unique alignment of 14 spacecraft near the Earth‐Sun line together with magnetohydrodynamic simulations, ground‐based magnetometer, and auroral observations allow a comprehensive timing analysis of the events leading to substorm onset. Perplexingly, prior to substorm onset Geotail measured for 26 min positive IMF Bz just upstream of the bow shock, while simultaneously MMS spacecraft measured several intervals of strong negative Bz (~ -30 nT) in the dayside magnetosheath. These strong pulses of negative Bz in the magnetosheath were associated with high dynamic pressure magnetosheath jets, likely created by foreshock transients during strongly radial IMF interval. Multipoint plasma and magnetic field measurements from ARTEMIS and THEMIS spacecraft were used to determine tail reconnection time at 8:14 and location at x=−33 RE. Ground‐based observations of Pi2 pulsations and auroral brightening, with observations of a dipolarization front by THEMIS spacecraft, allowed determination of substorm onset to be at ≈08:17. All MMS spacecraft detected the same magnetosheath jet structure with Bz=−25 nT at ∼08:00 while IMF was northward. Based on DMSP observations and timing analysis we propose that these jets produced magnetopause reconnection leading to final, critical flux enhancement in the midtail region, which may have triggered reconnection 12–14 min later after jet observations. We discuss the occurrence frequency of this type of solar wind discontinuity and implications of these new results to the internal vs external substorm triggering debate.||