ESWW15 - Topical Discussion Meeting

Topical Discussion Meeting - Solar Storms Forecasting and Analysis: Solar Flares, Coronal Mass Ejections and Solar Energetic Particles

Olga E. Malandraki (SWWT-TWG1 Spokesperson, National Observatory of Athens/IAASARS, Greece); Nicole Vilmer (SWWT-TWG1 Spokesperson, LESIA, Observatoire de Paris); Norma B. Crosby (Royal Belgian Institute for Space Aeronomy)
Wednesday 7/11, 14:00-15:15
MTC 00.10, Large lecture room

This Discussion Meeting focuses on the topics covered by the ESA SWWT Topical Working Group 1 (TWG1) sub-group on 'Solar Storms' i.e. the space weather impact of solar flares, coronal mass ejections and solar energetic particle events on the Heliosphere, and Earth's magnetosphere, ionosphere, and atmosphere. Abstracts are welcome covering observations, theory and modeling of these phenomena, and the recent advances of their forecasting by means of scientific results.

contributions
14:00-14:20

"Predictors of flaring activity and their relevance to CMEs"
Ioannis Kontogiannis Leibniz-Institut für Astrophysik Potsdam (AIP)

The complexity of the magnetic field of active regions is particularly associated with the presence of intense magnetic polarity inversion lines and strong shearing motions. Some of the most efficient magnetic parameters used in space weather prediction parameterize these observational aspects or contain relevant information. During the nominal duration of the FLARECAST project, several new promising parameters such as non-neutralized electric currents and Ising energy were developed and implemented. We summarize their implementation in an operational flare prediction service and examine their efficiency in flare prediction using a statistically significant active region sample of Solar Cycle 24. Aiming to set the ground for coronal mass ejections prediction, we also test the relevance of these new and other well-established predictors to the kinematic characteristics of eruptive flare CMEs.

14:20-14:40

"The imprints of the September 2017 event at Earth, Mars and STEREO-A and the implications of space weather and space radiation predictions for deep space explorations"
Jingnan Guo(1), Mateja Dumbovic(2), R F Wimmer-Schweingruber(1), Manuela Temmer(2), Yuming Wang (3), Henning Lohf (1), Astrid Veronig(2), Donald M. Hassler(4), Leila Mays (5), Cary Zeitlin(6), Bent Ehresmann(4), Johan L. Freiherr von Forstner (1), Henning Lohf(1), Bernd Heber(1), Oliver Witasse(7), Mats Holmström (8), Arik Posner (9)

(1) Institut fuer Experimentelle und Angewandte Physik, University of Kiel, Kiel, Germany. (2) Institute of Physics, University of Graz, Austria. (3) University of Science and Technology of China, Hefei, China. (4) Southwest Research Institute, Boulder, CO, USA. (5) NASA Goddard Space Flight Center, USA. (6) Leidos, Houston, Texas, USA. (7) European Space Agency, ESTEC – Science Support Office, The Netherlands. (8) Swedish Institute of Space Physics, Kiruna, Sweden. (9) NASA Headquarter, Washington DC, USA

Radiation is one of the most important risks to deep space exploration missions. In preparation, this requires a very timely and thorough study to better understand the space weather conditions and their effects as a baseline for the development of mitigation strategies against radiation risks. Radiation damage in space comes mainly form two sources, Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs). The GCR is omnipresent, ubiquitous, and is modulated by the heliospheric activities. GCR-induced radiation may cause long-term health issues including cancer, cardiovascular diseases, eye cataract and so on. On the other hand, intense SEP events can result in very high dose rates that may exceed the threshold for acute radiation syndrome (ARS). Such events, despite of being rather infrequent, are very unpredictable and could result in severe damage to humans and equipment and lead to failure of the entire mission. It is therefore especially important to better forecast them and plan mitigation against their effects. Radiation exposure from Solar Particle Events is the result of three major procedures: (1) particle acceleration at/near the Sun which are often related to the flare eruptions and associated shocks, (2) injection and transport of the accelerated particles in the heliosphere, i.e, particle propagation along and across the magnetic fields which are connected to the missions (that can be very differently connected compared to Earth), and (3) the atomic and nuclear interactions of particles with the local shielding environment (such as the spacecraft or the planetary atmosphere). Taking into consideration of these 3 factors, we will show our recent study of the September 2017 event which is seen on the surface of both Earth and Mars as well as at STEREO-A. These three locations have a heliospheric longitudinal separation of more than 240 degrees apart and they all saw the highly energetic particles with different time profiles, energy spectra and radiation intensities. We highlight the utmost importance of utilizing multi-spacecraft in-situ and remote sensing observations of the Sun and the heliosphere to better understand such extreme events and their dynamic effects across the heliosphere in particular at locations where human explorations may take place.

14:40-15:00

"Observation-based modelling of magnetised CMEs with EUHFORIA and implications for geo-effectiveness predictions"
Camilla Scolini KU Leuven, Belgium

Coronal Mass Ejections (CMEs) and their Interplanetary counterparts (ICMEs) are the primary source of space weather disturbances at Earth. The key ICME parameters responsible for driving strong geomagnetic storms are the dynamic pressure and the magnetic field Bz component at Earth, for which reliable predictions are not possible by means of traditional, over-simplified cone CME models. In order to overcome with such limitations, the newly developed EUHFORIA heliospheric model has been recently integrated with a magnetised flux rope CME model that allows to model the IMF components associated to ICMEs to a higher degree of accuracy. In this work we present a Sun-to-Earth comprehensive analysis of a selected set of Earth-directed CMEs, with the aim of testing the space weather predictive capabilities of the new flux rope CME model compared to those of the cone CME model. We first discuss the determination of the CME input parameters based on remote-sensing observations. For each event, we reconstruct the CME kinematical and geometrical parameters by means of single- and multi- spacecraft reconstruction methods based on coronagraphic CME observations. The magnetic field-related parameters of the flux ropes are estimated based on imaging observations of the photospheric and low coronal source region of the eruption. We then simulate the events with EUHFORIA, using both a cone and a flux rope CME model in order to compare the effect of the different CME kinematical and magnetic input parameters on simulation results at L1. We compare simulation outputs with in-situ observations of the ICMEs and we use them as input for the prediction of global geomagnetic activity indices, comparing our predictions with actual data records. We quantify the forecasting capabilities of such kind of approach by means of forecast verification metrics and we discuss its future improvements.

15:00-15:15

"Storm time thermosphere-ionosphere coupling at midlatitude consecutive to an associated flare/CME event; a case study"
Aziza Bounhir1, 2, Khalifa Malki1, Zouhair Benkhaldoun1, Jonathan J. Makela3, Mohamed Kaab1, Brian Harding3, Daniel J. Fisher3, Khaoula Elbouyahyaoui1, Amal Loutf1, Abdeladime El Fakhiri1 and Ahmed Daassou1.

1 High Energy Physics and Astrophysics Laboratory, Oukaimeden Observatory, Cadi Ayyad University, Marrakech, Morocco. 2 High Energy Physics and Astrophysics Laboratory, Faculty of Sciences and Techniques, Marrakech, Morocco. 3 Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Illinois 61801, USA, Urbana, IL, United States.

This paper explores the thermosphere-ionosphere coupling during associated flare/CME event at midlatitude through multi-instruments data analysis of the 27-28 February 2014 geomagnetic storm over Oukaimeden observatory (31.206◦N, 7.866◦W; 22.84◦N magnetic) in Morocco. The nature of the solar event determines the way the energy is deposited in the Earth’s geospace which then shapes the thermospheric winds and the related ionospheric dynamo. On 25 February 2014 at 00:49UT, an X4.9-class ﬂare was produced in NOAA active region (AR)1990. Associated with this ﬂare, an O-type CME occurred starting at 01:25:00, with a speed of more than 2000 kms−1. The flare-CME event was also associated to a wide spread solar energetic particle event observed by a number of spacecrafts. The CME-associated shock reached the Advanced Composition Explorer (ACE) satellite on 27 February 2014 16:30 UT with an increase in the density, temperature, velocity of the solar wind and the amplitude of the interplanetary magnetic ﬁeld and an inversion of the Bz magnetic ﬁeld component (at ∼16:30UT, |Dst|max = 90nT and Kp = 5). The instruments used to characterize the thermosphere/ionosphere system are; 1) a Fabry–Perot interferometer providing measurements of the thermospheric neutral winds and temperature based on observations of the 630 nm redline emission, 2) a wide-angle imaging system recording images of the 630nm emission and 3) a GPS station installed at Rabat city (33.998◦N,6.853◦W) providing measurements of the total electron content (TEC). The thermospheric winds not only clearly depart from their quiet-time climatological behavior but experienced two storm-time induced traveling atmospheric disturbances (TAD). The TAD is related to the modality of the solar event energy deposition into the Earth’s geospace. The first TAD came from the northern hemisphere, its speed was estimated to 550m/s and lasted for ~ 4 hours. The second TAD was trans-equatorial and lasted for ~ 3,5 hours. In general, the thermospheric winds experienced equatorward and westward flows of the storm-time induced circulation with speed as high as ~ 150 m/s. The thermospheric temperature increased about ~ 200 K more than average. The winds were compared to the DWM07 (Disturbance Wind Model) prediction model. The storm-time ionospheric electron density response was deduced from TEC measurements of the GPS station. The measurements revealed a positive storm as well as traveling ionospheric disturbances (TIDs). We have also observed a negative correlation between HmF2 and NmF2 during the passage of the TAD. The ionospheric electrodynamic response was explored with the camera images of equatorial plasma bubbles that occurred that night. A reversal in the drift direction was observed, indicating a reversal of the background electric ﬁeld direction due to the neutral wind disturbance dynamo. Furthermore, the EPB drifts tend to closely match the neutral winds, indicating that the dynamo was fully activated during this storm.