Session - Solar Storms: Flares, CMEs and Solar Energetic Particle (SEP) events

N. Vilmer, O. Malandraki, M. Georgoulis

This session will cover topics from the SWWT Topical Working Group Drivers of Space Weather (solar storms). The program will consist of invited talks, of oral contributions and posters about the understanding of

1. particle acceleration and transport processes at the Sun and in the inner heliosphere,
2. onset and propagation of CMEs in the interplanetary medium and subsequent interactions with the Earth's magnetosphere,
3. impact of flares (UV radiation, particles) on the Earth's atmosphere.

The session will also aim at discussing the research which should be performed in each domain to improve the forecasts of flares, CMEs and SEPs.

Talks
Tuesday November 24, 11:00 - 13:00, Delvaux
Wednesday November 25, 11:00 - 12:00, Delvaux

Poster Viewing
Tuesday November 24, 10:00 - 11:00, Poster area

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Talks : Time schedule

Tuesday November 24, 11:00 - 13:00, Delvaux

11:00	The onset of Coronal Mass Ejections: a parametric study	Zuccarello, F et al.	Oral
	Francesco P. Zuccarello, Guillaume Aulanier, Stuart A. Gilchrist
	LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris Diderot, 92190 Meudon, France
	Solar filaments are magnetic structures observed in the solar atmosphere that consist of plasma that is cooler and denser than their surroundings. They are visible for days – and even weeks – which suggests that they are in equilibrium with their environment before they disappear or erupt. Several models for solar eruptions have been developed that propose different trigger mechanisms. Understanding what triggers coronal mass ejections (CMEs) is a necessary step towards delivering accurate space weather forecasts. In this context, validating the different eruption mechanisms through observationally-inspired numerical magntohydrodynamic (MHD) simulations is a fundamental step towards understanding solar eruptions. We present the results of zero-beta MHD simulations of an asymmetric bipolar active region subjected to different line-tied photospheric motions. The implemented flows are designed to reproduce features that are commonly observed during the evolution of active regions, such as shearing/rotation of the magnetic polarities, convergence flows towards the polarity inversion line and active region dispersal and deformation. As a result of the sub-Alfvénic photospheric drivers, a magnetic flux rope capable of supporting prominence material is formed and under certain conditions erupts. The dynamics of the formation, the stability, and the eruption of the flux rope will be discussed.
11:12	Solar Demon: detecting flares, dimmings, and EUV waves in near real-time on SDO/AIA images	Kraaikamp, E et al.	Oral
	Emil Kraaikamp, Francis Verbeeck
	Royal Observatory of Belgium
	Solar Demon detects flares, dimmings, and EUV waves on Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) data. These events are closesly associated with coronal mass ejections (CMEs), and therefore provide useful information for early space weather alerts. Solar Demon is running at the Royal Observatory of Belgium, creating a near real-time catalog based on quick-look data - with a typical delay of 15 minutes - as well as a science catalog based on synoptic science data from May 2010 up to now. Solar Demon is the result of a collaboration between the FP7 projects COMESEP and AFFECTS. As a dedicated module in the automatic COMESEP alert system, Solar Demon provides flare locations which are used to predict the impact of Solar Energetic Particle (SEP) events. We present an overview of the Solar Demon system, with emphasis on the EUV wave monitor which now provides fully automatic EUV wave speed measurements in 24 sectors around the eruption center. We also show general statistics for the Solar Demon system for Solar Cycle 24 from May 2010 onwards, including latitudes of detections over time (e.g. 'butterfly' diagrams) and Carrington longitudes for both flare and dimming events.
11:24	Relationship between EUV waves and CMEs for space weather applications	Perez-suarez, D et al.	Oral
	David Pérez-Suárez[1], Jason Byrne[2], David Long[1], Eoin Carley[3,4]
	[1] University College London / Mullard Space Science Laboratory; [2] RAL Space; [3] Observatoire de Paris; [4] Trinity College Dublin
	Biesecker et al. (2002) found that all EUV waves have a CME associated with it but not vice versa. Their study was done with SoHO/EIT whose low cadence and data resolution would have limited the reliability of the coronal wave detections. Nowadays, SDO/AIA offers a significant improvement on the temporal and spatial resolution of coronal observations. Here we present a new analysis of the relationship between EUV waves and CMEs by using two robust, high-fidelity, automated detection codes: CorPITA for the EUV waves and CORIMP for the CMEs. We expect that the results of this ongoing analysis will help to characterise Earth directed CMEs when coronagraph data is not available, therefore providing another source of warning to the space weather community.
11:34	Predicting interplanetary shock arrival times from CME and flare data	Nunez, M et al.	Oral
	Marlon Núñez[1], Teresa Nieves-Chinchilla[2] and Antti Pulkkinen[2]
	[1] Universidad de Malaga; [2] NASA/GSFC
	An empirical model for predicting shock arrival times from CME and flare data is presented. This model, called SARM, implements a single differential equation that has been calibrated with a dataset of 120 shocks observed at distances from 0.72 AU to 8.7 AU. The model was calibrated by minimizing the mean absolute error (MAE), normalized to 1 AU. Although there is no physical relationship between flares and CME (the main shock driver), the correlations between both processes make possible the prediction of shock arrival times from flare data (peak flux, duration, and location), in addition to CME data (true or plane-of-sky speeds). For the prediction of shock arrivals at the aforementioned distances, the normalized MAE was 7.2 h. In order to face CME/flare data unavailability, SARM was also calibrated to be used with CME data alone or flare data alone, obtaining normalized MAE errors of 9.3 h and 8.4 h respectively. For the case of 1 AU, the best SARM's performance results were obtained when both true CME speeds and flare data were used, obtaining a MAE of 5.8 h. SARM was compared with the Empirical Shock Arrival model (Gopalswamy et al. 2005) and the numerical MHD-based ENLIL model (Odstrcil et al. 2004). We concluded that SARM's forecasting performance is somewhere between the performances of the ESA and ENLIL models. SARM may be run online with user-defined CME and flare data (spaceweather.uma.es/sarm). This model is used in the prototype system UMASHOCK that makes real-time shock arrival predictions to Earth (spaceweather.uma.es/umashock). SARM is also used in the ESA's funded project SEPsFLAREs system (García-Rigo at al., 2015) to contribute to the predictions of SEP peak and end times of central-meridian and eastern events.
11:46	Toward predictions of flare ribbons dynamics using magneto-frictional simulations	Pariat, E et al.	Oral
	Etienne Pariat[1], Antonia Savcheva[2], Edward E. Deluca[2]
	[1]  LESIA, Observatoire de Paris, PSL Research University, CNRS, UPMC Univ. Paris 06, Univ. Paris Diderot, France; [2] Harvard-Smithsonian Center for Astrophysics, USA
	Solar flares are characterized by a fast and important increase of the luminous intensity in the Ultraviolet and X-ray domains. These brightening are not random within the flaring active region and are spatially strongly localized: e.g. flare ribbons and kernels. The standard flare/eruption model states that particles, accelerated in the solar corona as a consequence of magnetic reconnection, flow down along the reconnected magnetic field lines, and eventually interact with the lowest layer of the solar atmosphere to generate electromagnetic radiation in UV and X-ray. Flare ribbons are thus the main observable that provides information on the magnetic field geometry of the reconnection region. The recent 3D extension of the standard flare model is now allowing a theoretical description of the dynamical shape and motions of ribbons during solar flares. The confrontation of numerical models with actual observations of flares is the next step forward in validating the 3D standard flare model. Using data initiated magneto-frictional simulations of 3 different observed flares/eruptions, we apply topological analysis to predict, from the numerical model, the evolving shape of the ribbons as these eruptions progress. We observe an excellent match between our predictions and the separating motions of the flare ribbons. This first and clear comparison of the ribbon dynamics with a data-initiated model provides very strong confirmation of the 3D standard flare model and guides the development of the next generation of observation-constrained flare/CME forecasting models.
11:58	Statistical study on the properties of solar energetic particles and associated solar phenomena in solar cycles 23 and 24	Miteva, R et al.	Oral
	R. Miteva[1,2], S. W. Samwel[3], M.V. Costa-Duarte[4] and HESPERIA-team
	[1] IAASARS, National Observatory of Athens, Greece; [2] Space Research and Technology Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria; [3] National Research Institute of Astronomy and Geophysics, Helwan, Cairo, Egypt; [4] University of Sao Paulo, Department of Astronomy, Sao Paulo, Brazil
	We report a statistical comparison between the properties of solar energetic particle (SEP) events (protons and electrons) and the eruptive phenomena in the solar corona and interplanetary observed after 1996. The topic is part of the Horzon2020 project HESPERIA. Here we present the main outcomes from this collaborative study with a focus on the occurrence rates, correlations, timings and positioning of the SEPs and their solar origin by means of in-situ and remote observations. Acknowledgement: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 637324.
12:10	PAMELA's Measurements of Solar Energetic Particles	Bruno, A et al.	Oral
	Alessandro Bruno on behalf of the PAMELA collaboration
	The PAMELA satellite experiment, operating since June 2006, is providing precise observations of the cosmic-ray radiation in low Earth orbits including interplanetary, geomagnetically trapped and albedo particles. In particular, PAMELA is accurately measuring the fluxes of Solar Energetic Particles (SEPs) related to solar flares and coronal mass ejections in a large interval (>80 MeV), bridging the low energy data by space-based instruments and the Ground Level Enhancement (GLE) data by the worldwide network of neutron monitors. Its unique observational capabilities include the possibility of measuring the flux angular distribution and thus investigating possible anisotropies related to SEP events. The analysis is supported by back-tracing techniques based on realistic geomagnetic field models, enabling to reconstruct the asymptotic directions of arrival with respect to the Interplanetary Magnetic Field (IMF). Magnetospheric effects, such as the variations in the geomagnetic cutoff latitude, are also evaluated investigating the role of IMF, solar wind and geomagnetic indexes (Kp, Dst and Sym-H) and their correlation with PAMELA observations. PAMELA results significantly enhance the characterization of SEP fluxes in the near-Earth space, constraining the scenarios for particle acceleration and transport mechanisms.
12:22	An illustration of shock acceleration of solar energetic electrons and ions: the solar minimum eruptive event on 26 April 2008	Klein, K et al.	Oral
	C. Salas Matamoros[1], A. Rouillard[2], K.-L. Klein[1]
	[1] Observatoire de Paris, LESIA, 92190 Meudon, France; [2] Université de Toulouse, UPS-OMP, IRAP, Toulouse, France
	Physical relationships between eruptive activity in the solar corona and solar energetic particle (SEP) events near Earth are discussed for a solar energetic particle (SEP) event during the last solar minimum, associated with an eruptive flare on 26 April 2008. The combined analysis of SEP measurements, radio, EUV and coronographic observations by the SoHO, STEREO and Wind spacecraft, and ground-based radio spectrographic and imaging observations from the Nan\c{c}ay Observatory leads us to the following conclusions: \begin{enumerate} \item The eruptive solar event itself, associated with the CME liftoff, the development of a post-eruptive arcade, and a type IV radio burst, did not contribute significantly to the observed SEPs. Weak and sparse radio signatures of electron escape from the corona suggest that most of the particles accelerated in the flaring active region remained confined in the corona. \item Radio-emitting electron beams at keV energies, escaping along open magnetic field lines rooted far from the flare site, were accelerated when the CME flank and EUV wave reached the footpoints of the open field lines through the radio source. \item MeV protons left the corona well after the CME liftoff , the radio emission, and the formation of post flare loops. Their release was not accompanied by any detected radio signature. It occurred when the CME front was more than 10 solar radii above the photosphere. The acceleration is ascribed to the shock wave driven by the outward expansion of the CME. \end{enumerate} We discuss the impact of these observations on scenarios of particle acceleration and propagation in solar eruptive events.
12:34	A study on Solar Energetic Particle Events from 1984-2013: Statistical Relations and their Implications for the Acceleration and Propagation of Particles	Anastasiadis, A et al.	Oral
	Athanasios Papaioannou[1], Anastasios Anastasiadis[1], Ingmar Sandberg[1], Manolis Georgoulis[2], Kostas Tziotziou[1], Georgia Tsiropoula[1], Piers Jiggens[3], Alain Hilgers[3]
	[1] IAASARS, National Observatory of Athens, Greece; [2] RCAAM, Academy of Athens, Greece; [3]ESTEC, ESA, The Netherlands
	Energetic processes on the Sun accelerate protons to GeV and electrons to tens of MeV energies, resulting in flux enhancements known as Solar Energetic Particle (SEP) events, recorded onboard an wide array of spacecraft within the inner heliosphere. SEP events are typically divided into two basic classes, so-called “gradual” and “impulsive” events. Impulsive SEP events are associated with short timescales and nominally are attributed to solar flares (SFs). Gradual events are associated with longer timescales with greater influence apportioned to coronal and interplanetary shocks driven by coronal mass ejections (CMEs). We examined the properties and associations of 314 SEP events (defined as distinct flux enhancements) which occurred in the years 1984 to 2013. The recorded properties of these SEP events include the peak proton flux and the fluence at several integral energies (E>10; 30; 60 and 100 MeV). The solar parameters determined include the maximum flare flux, the location of the flare (both the longitude and latitude), the impulsive (rise) time, the decay time and the duration of the associated SF, and the plane-of-sky velocity and size (as expressed by the width) of the associated CMEs. Furthermore, radio emission data were exploited, in an attempt to identify the presence (or not) of type III bursts, that signify the escape of SF particles along open magnetic lines, and their relative timing with respect to the start time of the SFs, associated to the SEP events. The velocity of the associated CMEs, as well as the maximum flare flux, seem to be strongly correlated to both the peak proton flux as well as the fluence of the SEP events in our catalogue - with the velocity of the CME being prevalent. We find a systematic presence of so-called hybrid or mixed events in the vast majority of our catalogue, which suggests that both SFs and CMEs have a role in the generation, acceleration and propagation of SEP events. This work has been funded through the “FORSPEF: FORecasting Solar Particle Events and Flares”, ESA Contract No. 4000109641/13/NL/AK
12:46	Non-stability of classical models of solar flares and possible solution of existed contradictions in approach to flare as to dynamical equilibrium of multi-scale percolation of the magnetic tensions and currents.	Pustilnik, L et al.	Oral
	Lev Pustilnik
	Israel Cosmic Ray and Space Weather Center of Tel Aviv University and Israel Space Agency
	Observed huge energy release of magnetic energy above active regions into thermal energy of heated plasma, kinematic energy of ejected coronal plasma (CME) and non-thermal energy of accelerated particles (solar cosmic ray) lead to uni-vocal conclusions – source of the energy for flare may be only force free magnetic fields and place, where process of abnormal fast conversion of magnetic energy to heating, kinematic motion and particle acceleration may be exclusively Thin Turbulent Current Sheet (TTCH), formed in region magnetic singularity or transition layers with magnetic shear between different magnetic flux. This classical approach meets with two principal contradictions: a) existence of the numerous ultra-fine current magnetic threads with constant sequences (and, correspondingly, magnetic fields in threads) from photosphere level to corona. The ensemble equilibrium of these current magnetic threads cannot be described as force-free in all volume and it must be caused by stabilization factor of freezing foots of the threads into massive photosphere; b) inner instability of classic turbulent current sheet what must be disrupted during first milliseconds to numerous turbulent and normal domains with dropped conductivity, controlled by local current density. Resulted pre-flare equilibrium state may be considered as ensemble of forced current-magnetic threads with strong interaction between neighbors’ elements and percolated magnetic tension through the ensemble from photosphere to corona. Increasing of magnetic tensions and currents more than critical level lead to formed 3-D ensemble of current’s network of thin current surfaces and threads, its disruption, tubulisation and conversion into percolated current system through resistors network. This approach allow to understand flare as phase transition in current percolated system with natural explanation of fractal power like distribution of flare frequency from flare energy and universal power like spectrum of accelerated particles (both electrons and protons) from their energy.

Wednesday November 25, 11:00 - 12:00, Delvaux

11:00	Transient response of the ionosphere to the X-ray solar flares	Chum, J et al.	Oral
	Jaroslav Chum[1], J. Urbář[1], J.Y. Liu[2]
	[1] Institute of Atmospheric Physics, Prague, Czech Republic; [2] Institute of Space Science, National Central University, Chung-Li 320, Taiwan
	Solar flares cause rapid increase of the ionization in the ionosphere owing to significant enhancement of solar radiation in the X-ray and EUV spectral range. The ionospheric response is investigated by continuous Doppler sounding system. The Doppler sounders installed in the Czech Republic (50 N, 14 E) and Taiwan (24 N, 121 E) are used in this study. The measured Doppler shifts are compared with 1s-resolution X-ray data from GOES satellites. We show that the largest Doppler shifts are observed at times when the time derivative of X-ray flux, d(X-ray)/dt, reaches its maximum rather than at times of X-ray flux maxima, when the Doppler shifts are around zero. Since the Doppler shift is proportional to the electron density change, it means that the loss processes (recombination and electron attachment) start to counteract the ionization production rate immediately to set the equilibrium.
11:12	Ionosphere effects of Solar X-ray bursts	Danskin, D et al.	Oral
	Donald Danskin
	Natural Resources Canada
	Solar X-ray bursts can effect radio wave communication through the ionosphere by cause enhanced absorption of radio wave in the D region. A study of many long duration X-ray flares with the Canadian Riometer Array has revealed that the absorption is proportional to the square root of the flux intensity. In addition, the response time is between 20-30 seconds absorption for the 30 MHz Riometers.
11:24	Flaring Rates Associated with Sunspot Group Evolution	Mccloskey, A et al.	Oral
	Aoife McCloskey, D. Shaun Bloomfield,Peter T. Gallagher
	School of Physics, Trinity College Dublin, Dublin 2, Ireland
	Solar flares are known to originate in sunspot groups, with increasingly complex magnetic structure leading to more frequent occurrence and often larger magnitude flares. Previously, McIntosh white-light classifications of sunspot groups and their historical flare rates have been used to calculate Poisson probabilities for flare forecasting. Here, we examine the temporal evolution of McIntosh classifications and calculate average flare rates for the following 24-hour periods. The impact that these evolution-dependent flare rates have on the performance of flare forecasts will be presented.
11:36	On the confined X-class flares in October 2014 produced by NOAA 12192	Veronig, A et al.	Oral
	Astrid M. Veronig, Julia K. Thalmann, Yang Su, Manuela Temmer, Wolfgang Polanec
	Kanzelhöhe Observatory/Institute of Physics, University of Graz, Austria
	NOAA 12192 was the largest active region (AR) on the Sun since NOAA 6368 in November 1990, and it developed to the most flare prolific AR in the present solar cycle no. 24, being the source of 6 X-class flares, 29 M-class flares and numerous smaller events. However, all the major flares it produced (i.e. all X-class flares and all M-class flares except one) were confined events, i.e. they were not associated with a coronal mass ejection (CME). As a consequence, the space weather effects of this period of major flaring activity in October 2014 were small. This raises the question what makes NOAA 12191 and its flaring activity so distinct, and whether we can understand its non-eruptive nature. To this aim, we performed a study on the magnetic environment and the flare energy release process of selected major flares produced by NOAA 12192. Key findings include the following: The confined flares all occurred in the core of the AR and the strong overlying arcade fields with small decay index served for the confinement, whereas the one eruptive M-class flare occurred on the border of the AR close to neighboring open field regions. A detailed analysis of the confined X1.6 flare on 2014 October 22 reveals a steep power-law hard X-ray spectrum (delta < 5). The total energy in non-thermal electrons derived is almost an order of magnitude larger than in eruptive flares of class X1, and corresponds to about 10% of the excess magnetic energy present in the active-region corona. The magnetic reconnection flux derived for the event lies well within the distribution of eruptive X1 flares. A large initial separation of the flare ribbons and no separation motion during the flare is observed, suggesting a confined reconnection site high up in the corona. In addition, enhanced emission at flare ribbon structures and hot loops connecting these structures is already present before the event starts. These findings are consistent with flare initiation by reconnection of localized newly emerging flux tubes with pre-existing large coronal loops.
11:48	Statistical analysis of CMEs' geoeffectiveness over one year of solar maximum during cycle 23	Schmieder, B et al.	Oral
	K. Bocchialini[1], M. Menvielle[2],  B.Schmieder[3], A. Chambodut[4], N. Cornilleau-Wehrlin[3], D. Fontaine[5], B. Grison[6], C. Lathuillère[7], A. Marchaudon[8], M. Pick[3], F. Pitout[9], S. Régnier[10], Y. Zouganelis[11]
	[1] IAS; [2] Uni. de Saint Quentin; [3] Observatoire de Paris; [4] Observatoire des Sciences de la Terre, Strasbourg; [5] LPP; [6] Institut in Prague; [7] IPAG, Grenoble; [8] Uni. d' Orleans; [9] IRAP; [10] Uni. de Lancaster, UK; [11] ESA
	Using different propagation models from the Sun to the Earth, we performed a statistical analysis over the year 2002 on CME's geoeffectiveness linked to sudden storm commencements (ssc). We also classified the perturbations of the interplanetary medium that trigger the sscs. For each CME, the sources on the Sun of the CME are identified as well as the properties of the parameters deduced from spacecraft measurements along the path of the CME related event, in the solar atmosphere, the interplanetary medium, and the Earth ionized (magnetosphere and ionosphere) and neutral (thermosphere) environments. The set of observations is statistically analysed so as to evaluate the geoeffectiveness of CMEs in terms of ionospheric and thermospheric signatures, with attention to possible differences related to different kinds of solar sources. The observed Sun-to-Earth travel times are compared to those estimated using the existing models of propagation in the interplanetary medium, and this comparison is used to statistically assess the performances of the various models.

Posters

Tuesday November 24, 10:00 - 11:00, Poster area

1	Flare forecasting improvements at the Met Office	Murray, S et al.	e-Poster
	Sophie A. Murray[1], Chloe Pugh[2], Francois-Xavier Bocquet[1], David Jackson[1]
	[1] Met Office; [2] University of Warwick
	Solar flares are potentially very damaging to a range of technologies and predicting their onset time and their magnitude remains a challenge to the space weather community. The processes involved in flaring are still not fully understood, however it is known that the complexity of active region magnetic fields is linked to the likelihood of flaring. Current flare forecasting efforts at the Met Office involve statistical modelling enhanced by space weather forecaster expertise. Recent efforts to develop tools to improve our predictions will be outlined here. This includes active region tracking methods to provide forecasters with more complex information of the magnetic field structures of regions of interest. Results from testing more accurate modelling of the 3D field structure of these regions will be presented, which will aid flare prediction as well as provide an improved input to our operational CME propagation model. Finally, some validation efforts for our current and developing flare forecasting efforts will be outlined, in connection with work for the EU Horizon 2020 FLARECAST project.
2	Flare Likelihood and Region Eruption Forecasting (FLARECAST) Project: an Overview	Georgoulis, M et al.	e-Poster
	Manolis K. Georgoulis and the FLARECAST team
	Research Center for Astronomy and Applied Mathematics (RCAAM) of the Academy of Athens
	This poster summarizes the aims and objectives of the European Commission FLARECAST project, the first space-weather project to be awarded in the framework of Horizon the 2020 Programme (PROTEC-1-2014). FLARECAST aims to redefine the state-of-the-art in solar flare prediction by developing an advanced flare prediction system that will rely on automatically extracted properties of solar active regions processed via cutting-edge flare prediction methods and validated using the most appropriate performance verification measures. With a 36-month period of performance (January 2015 - December 2017), FLARECAST will form the basis of the first quantitative, physically motivated and autonomous active-region monitoring and flare-forecasting system, openly available to space-weather researchers and forecasters in Europe and around the globe. This work has received partial support by the European Commission FLARECAST project, Research and Innovation Action # 640216.
3	Automated probabilistic solar flare forecast model based on Flarecast	Steward, G et al.	e-Poster
	Graham Steward, Matthew Francis, Michael Terkildsen, Vasily Lobzin, Iver Cairns
	Australian Space Weather Services, Bureau of Meteorology and School of Physics, University of Sydney
	The Australian Space Weather Service, Bureau of Meteorology, is implementing an automated probabilistic solar flare forecast model based on Flarecast, region characteristics and previous flaring history. Flarecast uses Solar Dynamic Observatory (SDO) HMI solar magnetograms to automatically identify active regions and their characteristics by analysing features on the solar disc. These characteristics, along with recent flaring history, have been used to train a statistical model for flare probability. Characteristics determined to be significant for flaring potential in the model training are used as inputs to the real time model. The model outputs in the form of probabilities for M- and X- class flares are generated in near real time as new input data becomes available. Predictions are uploaded every six hours to the Global Information System Center (GISC) Melbourne, part of the World Meteorological Organisation (WMO) Information System (WIS), to be made available by email and ftp after registering as a user. Features extracted from HMI magnetograms presently used in the model will be presented in the poster.
4	Understanding the coronal origins of solar energetic particles.	Carley, E et al.	p-Poster
	Eoin P. Carley, Nicole Vilmer[1], Peter T. Gallagher[2]
	[1] Paris Observatory, France; [2] Trinity College Dublin, Ireland.
	Eruptive activity in the solar corona is known to produce large-scale waves, shocks and coronal mass ejections (CMEs). This kind of activity is often associated with the in-situ detection of solar energetic particles (SEPs). However, the exact mechanism by which eruptions in the corona produces SEPs is still subject to much debate. In this study, I propose to analyse the coronal activity associated with multiple SEP events from the SEPserver catalogue. This will involve observations of EUV waves using the Atmospheric Imaging Assembly (AIA), which can provide more accurate wave/shock kinematics than has been achieved in the past. I will combine this with a detailed investigation of the particle acceleration and shock activity using existing and new spectrographs (e.g., Orfées, Nancay) and the Nançay Radioheliograph, whenever possible. Added to this will be a detailed analysis of CME kinematics and energetics using both the SOHO and STEREO coronagraphs. The study has so far compiled a list of ~40 events from the AIA era, and a detailed analysis of EUV, radio and white-light observations is already underway (see http://grian.phy.tcd.ie/~ecarley/ELEVATE/index.php). A statistical study of the physical properties of these events will lead to a better understanding of the coronal conditions that lead to the acceleration of particles.
5	Effect of solar storms on the geomagnetic field and the ionosphere. Case study: event of 18-24 februauary 2014	Rodriguez bouza, M et al.	p-Poster
	Marta Rodriguez-Bouza[1], Izarra Rodriguez-Bilbao[1], Consuelo Cid[2], Judith Palacios[2], Gracia Rodriguez-Caderot[3,4], Elena Saiz[2], Miguel Herraiz Sarachaga[1,5], Yolanda Cerrato[2], Antonio Guerrero[2]
	[1] Departamento de Física de la Tierra, Astronomía y Astrofísica I (Geofísica y Meteorología), Facultad de Ciencias Físicas, Universidad Complutense de Madrid (UCM), Spain; [2] Space Research Group – Space Weather, Departamento de Física y Matemáticas, Universidad de Alcalá, Alcalá de Henares, Spain; [3]Sec. Dptal. Astronomía y Geodesia, Facultad de Matemáticas, UCM, Spain; [4] Instituto de Matemáticas Interdisciplinar UCM, Spain; [5] Instituto de Geociencias, (UCM, CSIC), Spain
	Geomagnetic storms are disturbances of the terrestrial magnetic field which last several hours and have a global character. These phenomena are caused by solar wind includes IMF disturbances from coronal mass ejections and coronal holes, which interact with the magnetosphere. A geomagnetic storm may be associated with an ionospheric storm which is mainly characterized by a disturbance of the electron density of the F2-layer. Ionospheric storms have a major influence on GNSS observables and thus can affect the accuracy in positioning. This work describes the ionospheric disturbances that took place in mid-February ionosphere over Europe. We also study the geomagnetic field disturbances from local observatories as an example of a broader ongoing study that includes the main geomagnetic storms which took place that year. Solar triggers of the disturbances are identified, using interplanetary observations as support.
6	Ensemble Forecasting of Major Solar Flares	Guerra, J et al.	p-Poster
	Jordan Guerra[1,2], Antti Pulkkinen[2], Vadim Uritsky[1,2]
	[1] The Catholic University of America; [2] NASA Goddard Space Flight Center
	We present the results from the first ensemble prediction model for major solar flares (M and X classes). Using the active-region probabilistic forecasts from three models hosted at the Community Coordinated Modeling Center (NASA-GSFC) and the NOAA forecasts, we developed an ensemble forecasting method by linearly combining the flaring probabilities from all four methods. The combination weights were calculated using a sample of 13 actives regions between 2012 and 2014, containing 3120 forecasts and 1728 events. We constructed several different ensemble models (based on the values of the combination weights used) and found the conditions for which the ensemble method performed the best. This linear combination led to improving both the probabilistic and categorial forecasts in terms of the attributes (accuracy and reliability) and the Heidke skill score (HSS), correspondingly. The results of our investigation can be used for improving forecasts in a real-time scenario and therefore helping forecasters during the decision-making process.
7	Characteristics of Four SPE Classes According to Onset Timing and Proton Acceleration Patterns	Kim, R et al.	p-Poster
	Roksoon Kim[1], Kyungsuk Cho[1], Jeongwoo Lee[2], Suchan Bong[1], and Youngdeuk Park[1]
	[1] Korea Astronomy and Space Science Institute; [2] Chungnam National University
	In our previous work (Kim et al., 2015), we suggested a new classification scheme, which categorizes the SPEs into four groups based on association with flare or CME inferred from onset timings as well as proton acceleration patterns using multienergy observations. In this study, we have tried to find whether there are any typical characteristics of associated events and acceleration sites in each group using 42 SPEs from 1997 to 2012. We find: (i) if the proton acceleration starts from a lower energy, a SPE has a higher chance to be a strong event (>5000pfu) even if the associated flare and CME are not so strong. The only difference between the SPEs associated with flare and CME is the location of the acceleration site. For the former, the sites are very low (~1Rs) and close to the western limb, while the latter has a relatively higher and wider acceleration sites. (ii) When the proton acceleration starts from the higher energy, a SPE tends to be a relatively weak event (<1000pfu), in spite of its associated CME is relatively stronger than previous group. (iii) The SPEs categorized by the simultaneous proton acceleration in whole energy range within 10 minutes, tend to show the weakest proton flux in spite of strong related eruptions. Their acceleration heights are very close to the locations of type II radio bursts. Based on those results, we suggest that the different characteristics of the four groups are mainly due to the different mechanisms governing the acceleration pattern and interval, and different condition such as the acceleration location.
8	Observational evidence of the reconnection and related oscillatory dynamics in active region AR 11429 on March 6, 2012	Philishvili, E et al.	p-Poster
	E. Philishvili, B.M. Shergelashvili, T.V. Zaqarashvili, V. Kukhianidze, G. Ramishvili , M. Khodachenko, S. Poedts, P. De Causmaecker
	Ilia State University and KU Leuven
	Using the multi-wavelength observations by SDO/AIA and SDO/HMI instruments of the Active Region (AR) NOAA 11429 during 12:23 UT-12:56 UT on March 6, 2012, we present the dynamics of flaring coronal magnetic loops. The observed dynamics is interpreted as possible evidence for the magnetic reconnection. Further, we have detected intensity changes along the coronal loop, five bright blobs with diminishing propagating velocity , that led to magnetic reconnection. We have estimated characteristic periods of observed waves with examining space-time diagrams and intensity change analysis along the coronal magnetic loops. According to our findings, We present two different interpretations. First, the oscillations with calculated physical parameters provides evidence that these oscillations can be manifestation of longitudinal standing acoustic modes. Second, observed bright blobs could be signature of twisted coronal loop unstable to kink instability.
9	Two possible mechanisms of quasi-periodic pulsations during solar flare with unusual spatial dynamics	Kupriyanova, E et al.	p-Poster
	Kupriyanova E.[1,2], Kashapova L.[3], Ratcliffe H.[4], Myagkova I.[5]
	[1] Katholieke Universiteit Leuven, Department Wiskunde, Leuven, Belgium; [2] Central Astronomical Observatory at Pulkovo of RAS, Saint-Petersburg, Russia; [3] Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia; [4] University of Reading, UK; [5] Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
	There are two of most possible reasons for quasi-periodic pulsations observed during solar flares ― MHD oscillations in plasma waveguides and spontaneous oscillations in current sheets. The sets of arguments supporting the one or the other mechanism sometimes overlaid the each other. On example of solar flare with unusual spatial dynamics, we are discussing the realization possibility one of the mechanisms or combination of both mechanisms. The study is based on the multi-wavelength approach to analysis of the temporal, spatial, and spectral features of the flare emission. X-ray, microwave, and radio data are used to get information about the sources of the emissions from different layers of solar corona. Methods of correlation, Fourier, and wavelet analyses are used to examine temporal fine structures and relationships between the time profiles. We suppose that quasi-periodic accelerations of electrons caused by oscillations in the current sheet is most probable reason for the high-amplitude pulsations with period 1 minute during the impulsive phase of the flare. The minute-period damping oscillations observed during the decay phase are in good correspondence with second harmonic of the slow magneto-acoustic mode. The arguments indicating to the each mechanism are discussed based on the results of analysis.
10	Active longitude and solar flare, CME occurrences	Gyenge, N et al.	p-Poster
	N. Gyenge [1,2], T. Signh [3], T. Baranyi [2], A.K. Srivastava [3], R. Erdélyi [1,2]
	[1] Solar Physics and Space Plasmas Research Centre (SP2RC), School of Mathematics and Statistics, University of Sheffield; [2] Debrecen Heliophysical Observatory (DHO), Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Debrecen, P.O.Box 30, H-4010, Hungary; [3] Indian Institute of Technology (BHU), Department of Physics, Varanasi-221005, India
	Many flare prediction models employ the properties of active regions, such as morphological information, area or the magnetic field of sunspot groups. The spatial distribution of active regions has not been used widely, such as longitudinal distribution. If we assume the most flare and CME productive active regions tend to be located in or close to the active longitudinal belt then, this may allow to predict the geo-effective position of the domain of enhanced flaring (and CME) probability for a couple of month or years ahead. We studied the spatial and temporal properties of solar flares and CMEs. We have found that there is a narrow longitudinal belt of considerably enhanced sunspot activity migrating in the time-longitude domain. The migration path is similar to of a series of parabolic shape curves. A parabola-like section of the migration path does not follow the solar cycle and it has fluctuating temporal properties. The co-dominant longitudinal belt, phase shifted by 180 degrees, is relatively weak in comparison to the main active longitude. The main active longitude is not always detectable but the migration path of the activity is recognisable based on the DPD sunspot data in time interval between 1974 and 2014. Our results shows that the main active longitude plays a crucial role in the global position of solar flare and CME occurrence. The most flare and CME active groups appear in the 36 degrees width of the active longitude. The temporal variation of the number of solar flare shows fluctuations 0.8, 1.3 and 1.8 years within the active longitudinal belt. This temporal distribution may also provide an improved flare and CME forecasting opportunity.