Session - Open session on Recent Advances in Space Weather Science

The ESWW12 PC

This session is open to contributions detailing recent advances related to all aspects of space weather scientific research that are not covered in other sessions in the programme of this year's European Space Weather Week. In recognition of the fact that Space Weather is at the moment a buoyant field of research over the full extent of its multidisciplinary content, and not all of these topics can be granted a dedicated plenary session in the programme, we open this session to posters and oral presentations that may not fit the particular thematic focus of this year's ESWW. Contributions accepted for this sessions should demonstrate recent and timely advances in science underpinning space weather services and operations. Oral presentations will be selected from the contributed abstracts (i.e. no a priori invited talks will be included). Abstract proposers should carefully demonstrate the relevance of their work for Space Weather research and operations.

Talks
Monday November 23, 14:30 - 15:30, Mercator
Monday November 23, 16:30 - 18:00, Mercator

Poster Viewing
Monday November 23, 15:30 - 16:30, Poster area

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Talks : Time schedule

Monday November 23, 14:30 - 15:30, Mercator

14:30	Enhanced Observational Data Cadence and Advances in Discriminant Analysis for Solar Flare Prediction	Georgoulis, M et al.	Oral
	Manolis K. Georgoulis[1], D. Shaun Bloomfield[2], and the FLARECAST Team
	[1] Research Center for Astronomy and Applied Mathematics (RCAAM) of the Academy of Athens; [2] School of Physics, Trinity College Dublin
	The availability of pertinent data resources shapes one facet of prediction methods of phenomena manifested in these data. Another facet is shaped by the computational demands of prediction algorithms, whose objective should be to provide (near-) real-time forecast information. With SOHO/MDI full-disk magnetogram data provided every 96 min during solar cycle 23, computational demands of solar-flare prediction algorithms were rather relaxed. Full-disk magnetograms from SDO/HMI are now provided every 45 s, however, at a spatial resolution four times higher than that of SOHO/MDI. This has dramatically emphasized the need for much faster and efficient processing performance, albeit not at the expense of the quality of results. We show how increased data cadence can provide important, detailed time patterns that could be used to enhance future flare prediction. In conjunction, the availability of numerous flare predictors and other solar active-region properties exponentially expands the parameter space where discriminant analysis should aim to fully segregate flaring from non-flaring parameter populations, thus upgrading a purely probabilistic flare forecast into a categorical one. Milestones and challenges in this course are discussed, with emphasis on a hands-on, practical application. This research has received partial support by the European Commission FLARECAST project, Research and Innovation Action # 640216.
14:45	ULF foreshock under radial IMF: THEMIS observations and global kinetic simulation Vlasiator results compared	Palmroth, M et al.	Oral
	Palmroth, M.[1], Vainio, R.[2], Archer, M.[3,4], Hietala, H.[4], Kempf, Y.[1,5], Hoilijoki, S.[1,5], and von Alfthan, S.[1]
	[1] Finnish Meteorological Institute, Helsinki, Finland; [2] University of Turku, Turku, Finland; [3] MSSL, London, UK; [4] Imperial College, London, UK; [5] University of Helsinki, Helsinki, Finland
	For decades, a certain type of ultra low frequency waves with a period of about 30 seconds have been observed in the Earth's quasi-parallel foreshock. These waves, with a wavelength of about an Earth radius, are compressive and propagate obliquely with respect of the interplanetary magnetic field (IMF). The latter property has caused trouble to scientists as the growth rate for the instability causing the waves is maximized along the magnetic field. So far, these waves have been characterized by single or multi-spacecraft methods and 2-dimensional hybrid-PIC simulations, which have not fully reproduced the wave properties. Vlasiator is a newly developed, global hybrid-Vlasov simulation, which solves the six-dimensional phase space utilising the Vlasov equation for protons, while electrons are a charge-neutralising fluid. The outcome of the simulation is a global reproduction of ion-scale physics in a holistic manner where the generation of physical features can be followed in time and their consequences can be quantitatively characterised. Vlasiator produces the ion distribution functions and the related kinetic physics in unprecedented detail, in the global scale magnetospheric scale with a resolution of a couple of hundred kilometres in the ordinary space and 20 km/s in the velocity space. We run Vlasiator under a radial IMF in five dimensions consisting of the three-dimensional velocity space embedded in the ecliptic plane. We observe the generation of the 30-second ULF waves, and characterize their evolution and physical properties in time. We compare the results both to THEMIS observations and to the quasi-linear theory. We find that Vlasiator reproduces the foreshock ULF waves in all reported observational aspects, i.e., they are of the observed size in wavelength and period, they are compressive and propagate obliquely to the IMF. In particular, we discuss the issues related to the long-standing question of oblique propagation.
15:00	Particle acceleration in interplanetary shocks: quasilinear and hybrid-Vlasov simulations	Vainio, R et al.	Oral
	Rami Vainio[1], Alexandr Afanasiev[1], Markus Battarbee[1], Juuso Jaakola[1], Urs Ganse[2], Minna Palmroth[3], Sebastian von Alfthan[3], Otto Hannuksela[2,3], Sanni Hoilijoki[2,3], Yann Kempf[2,3], and Arto Sandroos[3]
	[1] Department of Physics and Astronomy, University of Turku, Finland; [2] Department of Physics, University of Helsinki, Finland; [3] Finnish Meteorological Institute, Helsinki, Finland
	We present a study of particle acceleration at travelling interplanetary shocks. We use two simulation codes for the purpose: (1) SOLPACS Monte Carlo simulation code and (2) Vlasiator hybrid-Vlasov simulation code. SOLPACS solves the evolution of the coupled system of energetic particles and Alfvénic turbulence upstream of a shock, using the guiding-centre approximation and quasilinear theory in the description of wave-particle interactions. It computes the intensity of accelerated particles and the power spectrum of waves on a single magnetic field line connected to the shock, assuming that particle transport across the field can be neglected. The advantage of this statistical approach is that large spatial domains can be covered without extensive computational demand, as the wave length of the resonant fluctuations is not resolved by the simulation, but in this approximation, no information on the wave phases can be obtained. Vlasiator, on the other hand, propagates the full ion distribution function and completely resolves the ion scale field fluctuations in front of the shock. This allows investigations of wave forms in the foreshock, but limits the extent of the computational domain possible with present computational resources. Our study is focused in the comparison of the simulation results with each other and observational data to reveal the range of validity of both codes in terms of energy spectra and spatial distributions of particles and the power spectra of waves in the foreshock region. We will discuss the implications of the results to shock acceleration in the solar corona and interplanetary medium.
15:15	Advanced modeling of low energy electrons responsible for surface charging	Ganushkina, N et al.	Oral
	Natalia Ganushkina[1, 2], Stepan Dugyagin[1]
	[1] Finnish Meteorological Institute, Helsinki, Finland; [2] University of Michigan, Ann Arbor MI, USA
	The fluxes of electrons with energies < 100 keV not usually analyzed and modeled in details when studying the electron radiation belts. These fluxes constitute the low energy part of the seed population, which is critically important for radiation belt dynamics. Moreover, energetic electrons with energies less than about 100 keV are responsible for hazardous space-weather phenomena such as surface charging. The electron flux at these energies varies significantly with geomagnetic activity and even during quiet-time periods. Significant variations in the low-energy electrons can be seen during isolated substorms, not related to any storm periods. Moreover, electron flux variations depend on the electron energy. Statistical analysis of AMC 12 CEASE II ESA instrument data (5-50 keV) and GOES MAGED data (40, 75, 150 keV) have revealed that electron fluxes increase by the same order of magnitude during isolated substorms with 200 nT of AE index and storm-time substorms with 1200 nT of AE index. If substorms are represented as electromagnetic pulses which transport and accelerate electrons additionally, how are their amplitudes determined, if not related directly to a substorm’s strength? Another factor of crucial importance is the specification of boundary conditions in the electron plasma sheet. We developed a new model for electron number density and temperature in the plasma sheet as dependent on solar wind and IMF conditions based on THEMIS data analysis. We present observational and modeling results on low energy electrons in the inner magnetosphere with newly-developed, time-dependent boundary conditions with a special focus on the role of substorms for electron transport and acceleration.

Monday November 23, 16:30 - 18:00, Mercator

16:30	Evolution of magnetized CMEs in the inner heliosphere	Poedts, S et al.	Oral
	Stefaan Poedts, Jens Pomoell
	Centre for mathematical Plasma-Astrophysics, KU Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium
	We will discuss 2.5D (axi-symmetric) magnetic flux rope models and 2.5D and 3D self-consistent magnetohydrodynamics (MHD) simulation models for the onset of CMEs under solar minimum conditions, and for their interaction with coronal streamers and subsequent evolution up to 1AU. The flux-rope models take into account the inner magnetic structure of the CMEs and quantify its effect on their IP evolution and interaction with the background solar wind, including erosion (due to magnetic reconnection), deformation (due to slow wind interaction), deflection (due to neighboring streamer interaction), etc. The self-similar CMEs are initiated by magnetic flux emergence/cancellation and/or by shearing the magnetic foot points of a magnetic arcade which is positioned above or below the equatorial plane and embedded in a larger helmet streamer. The overlying magnetic streamer field then deflects the CMEs towards the equator, and the deflection path is dependent on the driving velocity. The core of the CME, created during the onset process, contains a magnetic flux rope and the synthetic white light images often show the typical three-part CME structure. Observations are used to constrain the models by providing initial and boundary conditions. These solar observations, as well as the resulting characteristic plasma parameters they produce at 1AU compared to (ACE) observations, provide excellent tools to validate the models. These advanced CME models are now being integrated in the new inner heliosphere model Euhforia (the ‘European ENLIL’ model) we are developing. We are in the process of validating the model by comparing with observational data of a selection of well-documented cases as well as with ENLIL results. The current state-of-the-art will be reviewed.
16:45	Progress made during the first 18 months of the FP7 HELCATS Project	Harrison, R et al.	Oral
	Richard Harrison[1], Jackie Davies[1] and the HELCATS team
	[1] RAL Space, UK
	Understanding the evolution of the solar wind is fundamental to advancing our knowledge of energy and mass transport in the solar system, rendering it crucial to space weather and its prediction. The advent of truly wide-angle heliospheric imaging has revolutionised the study of both transient (CMEs) and background (SIRs/CIRs) solar wind plasma structures, by enabling their direct and continuous observation out to 1 AU and beyond. The EU-funded FP7 HELCATS project combines European expertise in heliospheric imaging, built up in particular through lead involvement in NASA’s STEREO mission, with expertise in solar and coronal imaging as well as in-situ and radio measurements of solar wind phenomena, in a programme of work that will enable a much wider exploitation and understanding of heliospheric imaging observations. With HELCATS, we are (1.) cataloguing transient and background solar wind structures imaged in the heliosphere by STEREO/HI, since launch in late October 2006 to date, including estimates of their kinematic properties based on a variety of established techniques and more speculative, approaches; (2.) evaluating these kinematic properties, and thereby the validity of these techniques, through comparison with solar source observations and in-situ measurements made at multiple points throughout the heliosphere; (3.) appraising the potential for initialising advanced numerical models based on these kinematic properties; (4.) assessing the complementarity of radio observations (in particular of Type II radio bursts and interplanetary scintillation) in combination with heliospheric imagery. We will, in this presentation, provide an overview of the HELCATS project and its progress in the first 18 months.
17:00	Plasma Flows in the magnetotail affecting the field aligned currents	Palin, L et al.	Oral
	Laurianne Palin, Hermann Opgenoorth
	Swedish Institute of Space Physics, Uppsala
	Substorms are global reconfigurations of the magnetosphere involving storage of solar wind energy in Earth’s magnetotail and its abrupt conversion to particle heating and kinetic energy. They can create strong changes in the magnetic field at ground-level (dB/dt) to cause substantial Geomagnetically-Induced Current (GIC) and high-energy particles. With this study we show that Bursty Bulk Flows (BBFs) in the tail, associated with small Dipolarisation Fronts (DFs), can create a small Substorm Current Wedge (SCW) when entering in the near tail, under quiet solar wind conditions. The mechanisms at play in the magnetosphere are the same as in substorms but very localised (magnetic variations can still be relatively strong). We show the first observation (for 8 hours long) of the ionosphere response to gradual plasma sheet heating, confirming the relation between the plasma sheet temperature and the ionosphere response in recent studies. We will discuss the impact of plasma flow on field-aligned currents and ionosphere under quiet solar wind conditions, before and after a substorm onset.
17:15	On the ionospheric response to CIR/HSS driven storms	Tsagouri, I et al.	Oral
	Ioanna Tsagouri
	National Observatory of Athens
	The evaluation of the performance of ionospheric prediction models reveals at several occasions certain limitations in their prediction efficiency during ionospheric disturbances that are driven by corotating interaction region/ high speed stream (CIR/HSS) storms. This shortcoming provides a critical challenge for both space weather research and applications, since although they are usually characterized by weak to moderate intensity, CIR/HSS storms are still able to produce significant ionospheric disturbances in global scale. However, they often evolve tapered off over many days and they are very common during periods of low solar activity, presenting an interesting contrast to CME driven events that should be investigated separately for space weather purposes. To help advances in our current knowledge and prediction ability, we attempt here the formulation of the ionospheric storm time response in terms of the F2-layer peak electron density during such events. In particular, actual observations of the foF2 critical frequency obtained from a global network of ground-based Digisondes are compared with climatological estimates to quantify the ionospheric disturbances and follow their evolution with respect to the latitude and local time through well established superposed epoch analysis. The investigation applies to a significant number of CIR/HSS driven storms of moderate intensity that occurred in the ascending phase of solar cycles 23 and 24, for comparison purposes. Solar wind parameters obtained at L1 point from ACE spacecraft, as well as magnetospheric/geomagnetic activity indices are also exploited as proxies of the solar wind energy input and dissipation in the Earth’s magnetosphere, respectively to discuss critical aspects of the behavior of CIR/HSS effects like their onset and ending times, which is of crucial importance for their effective prediction especially within operational environments.
17:30	Impact and modelling of the solar eclipse of 20 March 2015 on VLF measurements at different radio links	Wenzel, D et al.	Oral
	Daniela Wenzel, Jens. Berdermann, Norbert Jakowski
	German Aerospace Center (DLR)
	The solar eclipse on 20 March 2015 gives a chance of investigating the physical dynamics of the ionosphere. The lunar obscuration of the Sun and the corresponding short-term lack of solar radiation cause strong changes in the ionization of the entire ionosphere. This presentation focuses on changes of the lower layers of the ionosphere using VLF amplitude measurements of the Global Ionospheric Flare Detection System (GIFDS). By means of the VLF receiver at DLR Neustrelitz, the solar eclipse was being observed on different navy communication channels. As diverse propagation paths demonstrated different gradual obscuration of the Sun, the measurement results varied in strength and time. Finally, the VLF observations were modelled using the Long-Wavelength Propagation Capability code (LWPC) based on the obscuration function associated with each path.
17:45	Analysis of the delayed time response of geomagnetic activity to the solar wind	Maggiolo, R et al.	Oral
	Romain Maggiolo[1], Maria Hamrin[2], Herbert Gunell[1], Gael Cessateur[1], Lukas Maes[1], Timo Pitkänen[2]
	[1] Belgian Institute for Space Aeronomy, Belgium; [2] Umeå University, Sweden
	Geomagnetic activity results from the coupling between the solar wind and the interplanetary magnetic field (IMF) with the magnetospheric system. The amount of energy transmitted from the solar wind to the magnetosphere depends on the solar wind and IMF conditions. This energy is stored in the magnetosphere and is eventually released during dynamical events like geomagnetic storms and substorms which produce magnetic perturbations measured by ground magnetometers from which geomagnetic indices are produced. The geomagnetic response to the solar wind and to the IMF is not instantaneous. It occurs on time scales related to the processes involved in the energy transfer from the solar wind to the magnetosphere and to its storage and release inside the magnetosphere. We present an investigation of the correlation between a selection of geomagnetic indices (PC index, AE and SYM-H) and solar wind parameters (IMF and solar wind density, velocity and pressure) from 2000 to 2011. In particular we analyze the correlation and the time delay between the solar wind parameters and the response observed in the geomagnetic indices. We show that the response time involves several time scales, from a few minutes to several hours or more. We compare these results to typical magnetospheric time scales and discuss their implication for the understanding of the solar wind-magnetosphere coupling.

Posters

Monday November 23, 15:30 - 16:30, Poster area

1	Local geomagnetic indices and their role in space weather	Guerrero, A et al.	p-Poster
	Antonio Guerrero, Consuelo Cid, Elena Saiz, Judith Palacios, Yolanda Cerrato
	University of Alcala
	The analysis of local geomagnetic disturbances (specific longitude and latitude) have recently prove to play an important role in space weather research. Localized strong (high intensity) and impulsive (fast developed and fast recovered) geomagnetic disturbances are tipically recorded at high latitudes and commonly related to field-aligned currents. These type of disturbances are also recorded, less frequently, at mid and low latitudes, representing an important hazard for technology. In order to obtain geomagnetic disturbances (geomagnetic index) from the records at a certain observatory, a baseline has to be removed. The baseline is usually determined taking into account geomagnetic secular variation and solar quiet time. At mid-latitudes the shape of the daily solar quiet component presents a strong day-to-day variability difficult to predict. In this work we present a new technique capable to determine the baseline at mid-latitudes which allows us to obtain a high resolution local geomagnetic index with the highest accuarcy ever obtained at mid-latitudes.
2	Preliminary Results from the Recent NASA Radiation Dosimetry Experiment (RaD-X) High-Altitude Balloon Flight Mission	Mertens, C et al.	p-Poster
	C. J. Mertens[1], G. P. Gronoff[2], R. B. Norman[1], B. Hayes[1], A. Hands[3], K. Ryden[3], E. Benton[4], T. Straume[5], T. Lusby[5], B. Gersey[6], R. Wilkins[6], W. K. Tobiska[7], and X. Xu[2]
	[1]NASA Langley Research Center, Hampton, Virginia USA; [2]Science Systems and Applications, Inc., Hampton, Virginia USA; [3]University of Surrey, Guildford, England, UK; [4]Oklahoma State University, Stillwater, Oklahoma USA; [5] NASA Ames Research Center, Moffett Field, California; [6] Prairie View A & M University, Prairie View, Texas; [7]Space Environment Technologies, Pacific Palisades, California
	The NASA Radiation Dosimetry Experiment (RaD-X) high-altitude balloon mission was successfully launched from Fort Sumner, New Mexico USA on 25 September, 2015. Over 15 hours of science data were obtained from four dosimeters at altitudes above about 25 km. One of the main goals of the RaD-X mission is to improve aviation radiation model characterization of cosmic ray primaries by taking dosimetric measurements above the Pfotzer maximum before the production of secondary particles occurs. The second goal of the RaD-X mission is to facilitate the pathway toward real-time, data assimilative predictions of atmospheric cosmic radiation exposure by identifying and characterizing low-cost radiation measurement solutions. The four dosimeters flown on the RaD-X science payload are a Hawk version 3.0 Tissue Equivalent Proportional Counter (TEPC) manufactured by Far West Technologies, a Liulin dosimeter-spectrometer produced by the Solar Research and Technology Institute, Bulgarian Academy of Sciences, a total ionizing dose detector manufactured by Teledyne Microelectronic Technologies, and the RaySure detector provided by the University of Surrey. The RaD-X mission was also supported by TEPC measurements taken on an ER-2 aircraft flown out of the NASA Armstrong Flight Research Center, and Oklahoma State University TEPC and Liulin instruments which flew onboard a King Air C90 aircraft operated by the Columbia Scientific Balloon Facility at Fort Sumner. In this paper, preliminary results from the RaD-X campaign are presented, along with comparisons to predictions made by the NASA Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model.
3	A new statistical model for plasmaspheric hiss and its effect on electron losses	Kersten, T et al.	p-Poster
	Tobias Kersten, Richard B. Horne, Nigel P. Meredith, Sarah A. Glauert
	British Antarctic Survey
	A key part of the SPACESTORM project is to model variations in the Earth’s radiation belts. They depend on capturing some of the most essential physical processes including particle transport, acceleration and loss. One significant source of electron loss is known to be plasmaspheric hiss, which is a broadband and structureless electromagnetic emission that is found inside the plasmasphere. Its frequency range is between ~10 Hz and several kHz. To determine the effectiveness of plasmaspheric hiss, we have created a statistical wave model based on data from 7 satellites (DE1, CRRES, Cluster 1, Double Star TC1, THEMIS A, D, and E) to calculate drift and bounce averaged pitch angle and energy diffusion rates. The resulting model covers waves in the region from about L=1.5 up to the MLT and activity dependent plasmapause, and ranges from 3° to 60° in magnetic latitude. The model has a one hour MLT resolution and 6 levels of geomagnetic activity. The information on the wave normal angle distribution was gathered from Cluster measurements, and the density model was derived from CRRES measurements and therefore both are entirely based on satellite data. To assess their role on a global scale, the diffusion rates were included in the BAS Radiation Belt Model together with our most recent models for chorus and EMIC waves. We present the results of these simulations and compare the effects of our new statistical model with our old hiss model. Furthermore, we assess their importance compared with electron losses caused by chorus and EMIC waves.
4	Monitoring of the high-latitude ionosphere: new ESA Swarm mission	Zakharenkova, I et al.	p-Poster
	Irina Zakharenkova, Elvira Astafyeva
	Institut de Physique du Globe de Paris, Paris Sorbonne Cité, Univ. Paris Diderot, UMR CNRS 7154, 35-39 Rue Hélène Brion Paris 75013 France
	The Earth’s high latitudes are the region of the direct interaction of the Earth’s atmosphere and magnetosphere with solar wind and radiation. During major space weather events the complex physical processes of interactions within this region generate the various irregularities of different spatial scales and temporal dynamics. The important aspect is that the ionospheric irregularities affect greatly to the radio waves propagation, in particular Global Navigation Satellite System performance. The wide spectrum of the high-latitude ionospheric irregularities, their occurrence at different altitude regions and their spatial scales diversity proved the fact that there is no universal mechanism for the ionospheric irregularities generation. In this paper we introduce a new method for detection of the topside plasma irregularities at the high-latitude ionosphere. This approach is based on the GPS measurements from the Precise Orbit Determination (i.e. zenith-looking) GPS antenna onboard Low Earth Orbit (LEO) satellites. We report first results of this technique implementation for the ESA’s constellation mission Swarm. We consider several strong geomagnetic storms occurred during the years 2014-2015. The ionospheric irregularities detected in Swarm data with GPS technique are compared with the concurrent measurements of the in situ plasma density and field-aligned currents variations registered by three Swarm satellites. We demonstrate that LEO GPS can be considered as a new effective tool for monitoring the occurrence of the topside ionospheric irregularities and may essentially contribute to the multi-instrumental analysis of the space weather impact on the Earth’s ionosphere.
5	Understanding dawn-dusk asymmetry at the magnetopause	De keyser, J et al.	p-Poster
	Johan De Keyser[1,2], Lukas Maes[1], Stein Haaland[3] and Romain Maggiolo[1]
	[1] Belgian Institute for Space Aeronomy, Brussels, Belgium; [2] Center for Plasma Astrophysics, KULeuven, Leuven, Belgium; [3] University of Bergen, Bergen, Norway
	Dawn-dusk asymmetry at the magnetospheric boundary has been debated for a long time. A statistical study by Haaland et al. [2014] shows the magnetopause current layer at the dawn side to be on average somewhat thicker than at the dusk side. In this contribution we examine in more detail some of the possible reasons for this asymmetry, and we highlight its space weather relevance. To do so, we have used a kinetic TD model [De Keyser et al., 2013] to explore typical dawn and dusk magnetopause configurations. A first reason for asymmetry may be that the magnetosheath is not symmetric due to the ~4° aberration of the solar wind flow. Also, given the Parker spiral angle of ~45° at 1 AU, there is a difference in magnetic field line draping on both flanks. Walsh et al. [2012] have assessed magnetosheath asymmetry observationally. A comparison of the magnetopause at 06 and 18 LT shows an average difference in magnetosheath flow of 10 km/s and in magnetopause distance of 1.4 RE, with accompanying differences in local magnetospheric field strength. A second reason may be asymmetric magnetospheric conditions, e.g. with plasmaspheric plumes reaching out to the magnetopause mostly in the post-noon sector. Magnetopause asymmetries also exist because the dawn and dusk side physics does not exhibit mirror symmetry [De Keyser and Roth, JGR, 1998]. The sense of the electric field due to the shear flow as compared to the electric field due to charge separation is different at dawn and dusk. These asymmetries in the magnetopause thickness and shape reflect solar wind conditions, but in turn they may affect space weather. For instance, the different magnetopause thickness and distance may affect magnetopause “shadowing” of radiation belt particles. Also, the overall conservation of current couples magnetopause current to the ring current and magnetosphere-ionosphere current systems. J. De Keyser and M. Roth. Equilibrium conditions and magnetic field rotation at the tangential discontinuity magnetopause. JGR, 103:6653-6662, 1998. Walsh, B. M., D. G. Sibeck, Y. Wang, and D. H. Fairfield, Dawn-dusk asymmetries in the Earth’s magnetosheath, JGR, 117, A12211, 2012. J. De Keyser, M. Echim, and M. Roth. Cross-field flow and electric potential in a plasma slab. Ann. Geophys., 31, 1297-1314, 2013. S. Haaland, J. Reistad, P. Tenfjord, J. Gjerloev, L. Maes, J. De Keyser, R. Maggiolo, C. Anekallu, and N. Dorville. Characteristics of the flank magnetopause: Cluster observations, JGR, 119, 2014.
6	Cluster contribution to the dynamics of plasma waves in the radiation belts: implications for radiation belts forecast	Walker, S et al.	p-Poster
	V. V. Krasnoselskikh[1], V. Shastun[1], O. A. Agapitov[2], S. N. Walker[3], R. J. Boynton[3], M. A. Balikhin[3]
	[1] CNRS-LPC2E, Orleans, France; [2] SSL, University of California, Berkeley, U.S.A.; [3] ACSE, University of Sheffield, Sheffield, U.K.
	15 years of Cluster operations has provided a vast volume of data on inner magnetospheric plasma wave modes such as Chorus, Hiss, and EMW. This has resulted in significant advances in our understanding of these waves, their occurrence, and the mechanisms of their interaction with plasma particles. The main results from the Cluster mission and their implication for the modelling of high energy electron fluxes are reviewed and discussed.
7	The thermospheric auroral red line Angle of Linear Polarisation.	Lilensten, J et al.	p-Poster
	Jean Lilensten[1] , Mathieu Barthélemy[1] , Gérard Besson[2], Magnar Gullkstad Johnsen[3], Joran Moen[4]
	[1] IPAG UJF/CNRS, Grenoble, F-38041, France; [2] Institut Fourier, Université de Grenoble, France; [3] Tromso Geophysical Observatory University of Tromso, Norway; [4] Department of Physics, University of Oslo, Norway
	The Degree of Linear Polarisation (DoLP) of the auroral red line has more and more been explored over the last few years. In this work, we measure for the first time the calibrated Angle of Linear Polarisation (AoLP) and we compare it to the apparent angle of the magnetic field at the location of the red line emission. We show that the AoLP is a tracer of the magnetic field configuration. This opens new perspectives, both in the frame of space weather and in the field of planetology.
8	Multi-instrumental studies of ionospheric behavior during geomagnetic storms and solar flares : new aspects of the fundamental phenomena for Space Weather Applications	Astafyeva, E et al.	p-Poster
	Elvira Astafyeva and Irina Zakharenkova
	IPGP Paris France
	Research on the behavior of the Earth’s Ionosphere makes an important part of the Space Weather science, along with studies of the Solar activity and coupling between the interplanetary magnetic field, magnetosphere and ionosphere; at any time, it is important to know the global structure and distribution of the ionospheric plasma, because the ionosphere is responsible for the propagation of radio-signals at all wavelength, including those of the global navigation satellite systems (GNSS). Perturbations in the ionospheric electron density, also known as ionospheric irregularities, are the major source of GPS/GNSS amplitude and phase fluctuations that lead to losses of lock, cycle slips and other “failures” in GPS/GNSS performance. The most intensive ionospheric perturbations and GPS/GNSS slips are caused by geomagnetic storms and solar flares, which are, in turn, so far not well understood. New multi-instrumental era, with a large number of ground-based instruments installed, along with multiple satellite missions, aids to reveal new features of the global distribution of the ionosphere with unprecedented detail. One of the most interesting recent findings is a demonstration of altitudinal difference of the ionospheric behavior during geomagnetic storms, and occurrence of intensive ionospheric irregularities in the topside ionosphere (above the ionization maximum). These studies, along with many others, show 1) the necessity of future studies of the topside ionosphere, 2) the power of multi-instrumental analysis, and its importance for both fundamental science and the Space Weather. In our contribution, we show several examples of multi-instrumental (from ground-based and space-borne instruments) analysis of the ionospheric behavior during very recent geomagnetic storms and solar flares. We pay special attention on new aspects of these phenomena which can be important for Space Weather applications.
9	Differences in Midlatitude Ionospheric Response to Magnetic Disturbances at Northern and Southern Hemispheres	Buresova, D et al.	p-Poster
	Dalia Buresova, Jan Lastovicka, Jaroslav Chum, Dagmar Novotna and Jaroslav Urbar
	Institute of Atmospheroc Physics, CAS
	Nowadays studies related to effects of space weather phenomena on the Earth’s ionosphere are of great interest because of their importance to sophisticated space- and ground-based infrastructure. In order to give users advanced and reliable information/warning of changing space weather conditions that may affect a diverse range of technological systems, thoroughgoing knowledge of disturbed ionosphere behaviour and its solar activity, local time, seasonal, latitudinal/longitudinal dependence, as well as possible hemispherical asymmetries are needed. Here the investigations of differences in ionospheric response to geomagnetic disturbances are based on data of selected ionospheric sounding stations located at different magnetic latitudes and longitudes of the Northern and Southern Hemispheres. The variability of main ionospheric parameters, critical frequency foF2 and its height hmF2, obtained for Euro-African and American longitudinal sectors of both hemispheres for initial, main and recovery phases of magnetic storms of different intensity, is analysed for selected events of the last two solar cycles (23 and 24). Ionospheric response to weak geomagnetic storms during the deep 23/24 solar minimum is found to be comparable with or even slightly stronger than that of strong storms under higher solar activity conditions, which might be partly related to specific features of geomagnetic activity in this solar minimum. As for possible hemispheric asymmetry, in average the asymmetry of ionospheric response to geomagnetic storms at middle latitudes is not a dominant and/or strong feature. The asymmetry in individual events may be well pronounced both in foF2 and hmF2, but mostly it seems to be an impact of other factors like seasonal variation, magnetic coordinates or local time.
10	Effect of Solar eclipse of March 20, 2015 on the ionosphere	Scotto, C et al.	p-Poster
	Dario Sabbagh[2], Alessandro Ippolito[1] , Vittorio Sgrigna[3] , Carlo Scotto[1]
	[1] Istituto Nazionale di Geofisica e Vulcanologia; [2] Istituto Nazionale di Geofisica e Vulcanologia -Università Roma Tre; [3] Università Roma Tre
	The effect on the ionosphere of solar eclipse of March 20, 2015 on different ionospheric layers is studied, with particular reference to changings in critical frequencies and heights. The behavior of an adaptive 3D assimilative model is also studied.
11	An Assessment of Pc5-like Pulsations Observed During the Carrington Storm	Thomson, A et al.	p-Poster
	Alan Thomson
	British Geological Survey, West Mains Road, Edinburgh EH9 3LA, UK
	The Greenwich observatory magnetogram for 2nd September 1859 shows prolonged periods of ULF Pc5-like pulsations, most likely global Pc5s driven by the solar wind during the recovery phase of the storm. Unlike the very rapid and presumably very high amplitude variations that are off scale during the peak of the magnetic storm on 1st September 1859, the pulsation events have been well preserved in the records of the time. (Further information on and images of the scanned Carrington magnetograms can be found at www.bgs.ac.uk/data/Magnetograms/home.html.) We therefore try to put the measured amplitude and duration of the Carrington Pc5 pulsations into some context by analysing them in relation to modern day records. For this we analyse Pc5 pulsations occurring in data from the Hartland, UK observatory, which is geographically close to Greenwich, and Wingst observatory, Germany. Wingst, in particular, has a geomagnetic latitude believed to be closer to that of Greenwich at the time of the Carrington storm (around 50 degrees north). For both observatories there are complete records from the early 1980s to the present day, providing a continuous data set, over three decades, containing many severe storms from the recent past. We use 1-minute mean horizontal component field data that are filtered in the Pc5 150-600 second pass band, and in other pass bands for comparison, by means of an 8th order Butterworth filter. By means of various measures (e.g. amplitude, duration, root-mean-square over the day, and others) we try to determine how atypical the Carrington pulsations were. We discuss issues such as how the differing magnetometer responses to high frequency magnetic variations, ‘then’ and ‘now’, may affect the interpretation of results across more than 150 years and how the results depend on time of day.
12	Data Assimilation Techniques for Ionospheric Reference Scenarios (DAIS)– project overview and achieved results	Gerzen, T et al.	p-Poster
	Tatjana Gerzen[1], Volker Wilken[1],  Mainul Hoque[1],  David Minkwitz[1] and Stefan Schlüter[2]
	[1] German Aerospace Center (DLR), Institute of Communications and Navigation; [2] European Space Agency ESA - EGNOS Project Office
	The ionosphere is the upper part of the Earth’s atmosphere between about 50 km and 1000 km above the Earth’s surface, where sufficient free electrons exist to affect the propagation of radio waves. Therefore, the treatment of the ionosphere is a critical issue for many applications dealing with trans-ionospheric signals such as GNSS positioning, GNSS related augmentation systems (e.g. EGNOS and WAAS) and remote sensing. The European Geostationary Navigation Overlay Service (EGNOS) is the European Satellite Based Augmentation Service (SBAS) that provides value added services, in particular to Safety of Live (SoL) users of the GNSS. In the frame of the European GNSS Evolution Programme (EGEP), ESA has launched several activities, which are aiming to support the design, development and qualification of the future operational EGNOS infrastructure and associated services. Ionospheric Reference Scenarios (IRSs) are used by ESA in order to conduct the EGNOS end-to-end performance simulations and to assure the capability for maintaining integrity of the EGNOS system especially during ionospheric storm conditions. The project Data Assimilation Techniques for Ionospheric Reference Scenarios (DAIS) – aims the provision of improved EGNOS IRSs. The main tasks are the calculation and validation of time series of IRSs by a 3D assimilation approach that combines space borne and ground based GNSS observations as well as ionosonde measurements with an ionospheric background model. The special focus thereby is to demonstrate that ionospheric radio occultation measurements can significantly contribute to fill data gaps in GNSS ground networks (particularly in Africa and over the oceans) when generating the IRSs. In this project we selected test periods of perturbed and nominal ionospheric conditions and filtered the collected data for outliers. We defined and developed an applicable technique for the 3D assimilation and applied this technique for the generation of IRSs covering the EGNOS V3 extended service area. Afterwards the generated 3D ionosphere reconstructions as well as the final IRSs are validated with independent vertical sounding observations and JASON 1 and 2 derived vertical TEC. This presentation gives an overview about the DAIS project and the achieved outcomes. We outline the assimilation approach, show the reconstruction and the validation results and finally address open questions.
13	Influence of latitude on the recovery time of intense geomagnetic disturbances	Cerrato, Y et al.	p-Poster
	Yolanda Cerrato, Antonio Guerrero, Elena Saiz, Consuelo Cid, Judith Palacios
	Departamento de Física y Matemáticas. Universidad de Alcalá. Spain
	The response time to recover quiet time after a geomagnetic storm is an important element to forecast in order to improve space weather services. Geomagnetic indices elaborated by averaging records from several observatories are commonly used for space weather purposes and recovery time models are provided for these indices. However, geomagnetic disturbances at terrestrial surface are strongly dependent on both longitude and latitude. As a result, significant local disturbances (and their recovery phase) are missed by these indices. High-resolution local geomagnetic indices appear as more suitable proxies to evaluate the actual risk at a particular place during geomagnetic storms. In this work we analyse the recovery phase of local magnetic disturbances. The set of events is chosen from those catalogued at least as moderate in the period 1998-2012 by the local LDiñ index (LDiñ<= - 100 nT), which is elaborated from records of SPT observatory (Spain). For every event we fit a hyperbolic model to local magnetic records of observatories located at different latitude but similar longitude. This study will allow us to find how the hyperbolic model fits at any latitude and to analyse the relationship between recovery time and intensity of the disturbance.
14	An empirical approach for geomagnetic Kp/ap predictions using solar wind parameters	Luo, B et al.	p-Poster
	B. Luo, J. Gong, S. Liu
	National Space Science Centre
	The prediction of geomagnetic indices is of great interests, both for space weather services and for helping understand the physical interaction process between the solar wind and the magnetosphere. Considerable success has been realized in studies of neural network-based predictions of the Kp index. However, neural network models do not have an explicit formulation that is publicly available that can be easily adapted by forecasting centres, or can be used for direct comparison with other data. In this work, we introduce an empirical approach for forecasting geomagnetic Kp/ap indices, after comprehensively investigate the correlations between high time resolute solar wind parameters and geomagnetic disturbances. We paid much attention to the time lag of reaction of geomagnetic disturbance to the upstream solar wind, in order to increase the lead-time of the prediction as much as possible. This is very important for operational prediction, considering that the only reliable input of the model is solar wind monitoring data by ACE at the L1 position, where the solar wind takes only about 1 hour to arrive at the Earth. Finally, our model gives a linear correlation coefficient of 0.91, a prediction efficiency of 0.82 between the predicted and observed data for years 1995-2004. What’s more, compared to the former models, our model increases the lead-time of prediction by 40 minutes. Our model can be easily adapted for real-time predictions at any forecasting centres and can be used as a benchmark against which other methods can be measured.
15	Overview of the 2015-03-17 geomagnetic storm and its impact on GNSS positioning in Norway	Jacobsen, K et al.	p-Poster
	Knut Stanley Jacobsen, Yngvild Linnea Andalsvik
	Norwegian Mapping Authority
	We present our observations and analysis of the surprise storm on the 17th of March 2015. On that day, a CME impact created a geomagnetic storm of surprising strength (compared to the forecasts). While not among the strongest storms of all time, it is the strongest storm of the current solar cycle (measured by e.g. Kp or Dst). We will present an overview of the storm, including the solar wind conditions and the resulting disturbances (TEC, ROTI, scintillation) in the ionosphere. We will show how this storm affected GNSS positioning at several locations in Norway.
16	Data-constrained MHD Simulations of CME Initiation and Propagation	Savcheva, A et al.	p-Poster
	A.S. Savcheva, R. Evans, B. van der Holst, N. Lugaz
	Harvard-Smithsonian Center for Astrophysics
	We perform the first global data-constrained MHD simulation of a CME with the Space Weather Modeling Framework (SWMF). This code has fully developed state-of-the-art steady state solar wind driven by Alfven wave turbulence, in which disturbances can be propagated using ideal or resistive MHD, full thermodynamics, and various other physics. The CME can be propagated to 1AU and the interaction with the magnetosphere can be studied. The initial condition for the simulation is the best-fit 3D non-linear force free field model obtained with the flux rope insertion method of the active region CME on April 08, 2010. The boundary condition is a synoptic magnetogram from SOLIS, with a high resolution HMI piece around the active region. We discuss the newly developed capabilities built-in into SWMF for producing fully data-constrained models of CMEs. We show the initiation and propagation of the CME within 10Rsun. We compare simulated LASCO white light and SDO/AIA EUV images with the observations and demonstrate the power of using data to constrain the initial and boundary conditions ion such a simulation. We discuss the future directions of the project and the potential advances to space weather prediction in terms of reproducing the in situ signatures and the Bz component at 1AU.
17	Geomagnetic response at mid-latitude locations to the interplanetary triggers of H-spikes	Saiz, E et al.	e-Poster
	Elena Saiz, Consuelo Cid, Antonio Guerrero, Judith Palacios, Yolanda Cerrato
	University of Alcala, Space Research Group-Space Weather (SPAIN)
	Abrupt southward turnings of IMF Bz (> 10 nT/min) along with high solar wind pressure have been pointed out recently as the interplanetary triggers of significant but short time disturbances on the horizontal magnetic field component (H) recorded at some mid-latitude observatories. This kind of magnetic disturbance, which has been labeled as H-spike for its similarity to the Carrington profile at Colaba, develops in less than one hour and is highly asymmetric in longitude. Its origin is not an enhanced ring current, but FACs, and indices such as SYM-H or Dst cannot detect it. In this work we start searching for the proposed interplanetary triggers and then we analise the corresponding ground magnetic response at mid-latitude observatories located in the dawn-noon MLT sector searching for H-spikes. As a starting point, we select those events that present fast forward shocks with speed jump larger than 200 km/s and magnetic field ratio larger than 4 from the Heliospheric Shock Database generated by the University of Helsinki.
18	Energy estimation of the interplanetary plasma during strongest geomagnetic storms of the current solar cycle on 17-19 March 2015	Velinov, P et al.	e-Poster
	Yordan Tassev[1], Lachezar Mateev[1], Peter Velinov[1], Alexander Mishev[2]
	[1] Institute for Space Research and Technology, Bulgarian Academy of Sciences, Sofia; [2] ReSolve CoE, University of Oulu, Finland
	The geomagnetic storms on 17-19 March 2015 are the most powerful storms during the current solar cycle. They develop in time period of three days. In the first day, 17-th March, the geomagnetic index Kp reaches the maximal value Kp = 8, in the second day Kp = 6 and in the third day Kp = 5, respectively. The considered geomagnetic storms occur in the decreasing part of the 24-th solar cycle. They result from the interaction between the solar plasma shock wave, which is created by the Coronal Mass Ejection on 15 March 2015 and the terrestrial magnetosphere. Before reaching the magnetosphere, the shock wave passes through the equilibrium point of Lagrange L1. It occurs 1 hour before the interaction of the shock wave with the magnetosphere. In this point are situated some space probes as ACE, which measure the interplanetary medium parameters: such as solar wind velocity and density, magnetic field intensity and interplanetary plasma temperature. Using the on this way measured parameters, we calculate the following parameters the kinetic energy: ET = (3/2) N k Tp; the magnetic energy: EM = |B|2 / (2mo); and the thermal energy: EK = (1/2) N |V|2 of the solar plasma flux. Here N is the plasma density of solar wind, k is Boltzman constant, Tp is solar protons temperature, B is the interplanetary magnetic field intensity, mo is magnetic permeability of vacuum, V is solar wind velocity. Comparing the so calculated energies during the geomagnetic storms with the energies before them, it would be possible to determine the variations of each of them. In dependence on the degree of the changes of each energy, it would be possible to use them as an indicator for a future geomagnetic storm. The so proposed method is applied for this case of the geomagnetic storms on 17-19 March, but it can be applied for other events also. On this way we could improve our space weather forecasts. In the investigated period a powerful Forbush decrease of the galactic cosmic rays (GCR) intensity occurs. It reaches GCR intensity reduction 6%, which is seen from the data of the neutron monitor in Oulu, Finland. A quantitative analysis of the ionization effects in the ionosphere and the atmosphere in the investigated time period 17-19 March 2015 is made, using the changes of the geomagnetic cut-offs rigidities of GCR.
19	New advantages of the dense GPS networks to study the ionospheric irregularities	Cherniak, I et al.	e-Poster
	Iurii Cherniak[1], Irina Zakharenkova[2]
	[1] Space Radio-Diagnostic Research Center University of Warmia and Mazury; [2] Institut De Physique Du Globe De Paris
	The Earth’s high latitudes are the region of the interaction of the Earth’s atmosphere and magnetosphere with solar wind and interplanetary magnetic field. The complex physical processes within this region generate the various ionospheric irregularities of different spatial scales and temporal dynamics. The most intense irregularities have been observed during ionospheric storms, resulted from the significant increase of an auroral particle precipitation, high latitude ionospheric electric fields and currents lasting several hours or more during magnetospheric disturbances. Radio signals passing through the ionosphere suffer varying degrees of rapid variations of their amplitude and phase - signal fluctuations, are created by random irregularities of the medium’s refractive index. In this paper we study of the high-latitude ionospheric irregularities development during severe geomagnetic storm March 17, 2015 with use of the transionospheric propagated GPS signals. This storm is the largest one since the beginning of the 24th solar cycle. Multi-site GPS observations - more than 2500 ground-based GPS stations were involved for analysis of the dynamics of the ionospheric irregularities at the Northern and Southern Hemispheres. The strong disturbance of the geomagnetic field on March 17, 2015 leaded to the intense particle precipitation and an enhancement of the substorm activity. It was reported that during March 17-18, 2015 aurora was observed at different locations around the globe, even at midlatitudes as New Zealand in the Southern Hemisphere as well as in the United States and Europe in the Northern one. The most intense ionospheric irregularities were registered more than 24 h starting 07 UT of March 17. The intensification of irregularities was associated with the Bz turn, correlate well with AE and PC indices and processes related to the auroral particle precipitation. We find the hemispheric asymmetries in the ionospheric irregularities intensity and spatial structure. Over North America the ionospheric irregularities oval expanded to ~45N latitude. For the middle and high latitude ionosphere the strong irregularities were found to be related with the formation of storm enhanced density and polar tongue of ionization, as well as deepening of the main ionospheric trough. Significant increase of the irregularities intensity within the polar cap region of both hemispheres was associated with the polar patches formation and evolution.
20	2D multi-fluid modeling of neutral-ion interactions in the solar chromosphere	Maneva, Y et al.	e-Poster
	Yana Georgieva Maneva[1], Alejandro Alvarez Laguna[1,2], Stefaan Poedts[1] and Andrea Lani[1,2]
	[1] KU Leuven, CmPA, Leuven, Belgium; [2] von Karman Institute for Fluid Dynamics, CFD group, Aeronautics and Aerospace, Rhode Saint-Genèse, Belgium
	Neutrals play an important role in the evolution of weakly ionized plasmas, such as the solar chromosphere, where the number density of neutrals often exceeds the number density of protons. In this work we perform 2D two-fluid simulations to study the interaction between ions and neutrals in a gravitationally stratified collisional media. The model considers the electrons and ions as a single fluid within the resistive MHD approach with Coulomb colissions and anisotropic heat flux determined by Braginskii’s transport coefficients. Separate mass, momentum and energy conservation equations are considered for the neutrals and the interaction between the two fluids is determined by momentum and energy exchange due to collisions and chemical reactions, such as electron impact ionization, radiative recombination and charge exchange. An ideal gas equation of state with equal initial temperatures for the ions and the neutrals and different density profiles. The initial temperature and density profiles are height-dependent and follow VAL C atmoshperic model for the solar chromosphere. First we search for a chemical and collisional equilibrium between the ions and the neutrals in a non-magnetized media. This is done to avoid unphysical outflows and artificial heating induced by initial pressure imbalances. Next we consider ion-neutral interactions in magnetized plasma with an initial magnetic profile, corresponding to emerging magnetic funnel. We search for a self-consistent magnetized initial steady state, where gravity, collisions and chemical reactions are in balance.