ESWW11 - Session

Session - Solar Energetic Particle Events: from forecast to radiation impact

Mike Marsh, Mark Dierckxsens, Thomas Berger

This session aims to foster an environment where the communities conducting the science/forecasting of solar energetic particle events and those concerned with the physical impacts of the subsequent radiation events on human activities, technology and other physical effects may confer and exchange knowledge. There is currently much effort in developing forecasting and alert systems of solar energetic particle radiation events with the intent that these tools will be useful for civil aviation, human space flight, and satellite operations. However, these tools and research are often being developed without the direct involvement of the people concerned with the physical impact of these radiation events. It is not always clearly understood by the space weather community what parameters from space weather research/forecasts are desired by the end user concerned with radiation impacts, and what procedural impact solar events have on human spaceflight and operations. This session invites contributions with a view to connecting the "beginning and end" aspects of space weather research/tools and the real world impact. We solicit contributions on solar energetic particle research/forecasts which have practical space weather applications/effects with a focus on what information can be provided to the end user. Contributions are also warmly welcomed from the other point of view, concerning the real world impacts of solar radiation events on space flight, satellites, aviation, solar system effects, and how a forecasting system could satisfy end user needs.

Talks and First Class Posters
Wednesday November 19, 09:00-11:00, 11:30-13:00, auditorium Roger

Poster Viewing
Wednesday November 19, 10:30-11:30, area in front of auditorium Roger.

Talks and First Class Posters

The numbering of the posters might differ from the numbering on the page with the short overview without abstracts.

Oral	9:00 am	Forecasting and Nowcasting Reductive Statistical Schemes for Solar Energetic Particle Events
		Sandberg, I¹; Anastasios, A²; Papaioannou, A²; Georgoulis, M³; Tziotziou, K²; Jiggens, P⁴
		¹Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens; ²National Observatory of Athens; ³Academy of Athens; ⁴ESA/ESTEC
		Solar Energetic Particle (SEP) events enhance the radiation exposure of humans and systems in space and at aircraft altitudes. In extreme cases at high polar latitudes this can constitute a major radiation hazard. During launch campaigns the potential for catastrophic malfunction brought about by radiation-induced single event effects resulting in the loss of spacecraft is significantly increased supporting the case for the development of improved SEP event forecasts with longer forecasting horizons. CMEs are known to be the major driver of large SEP enhancements but the prediction of CMEs is not mature. Flare prediction, on the other hand, is more mature and there is a correlation between increase flaring activity and CMEs, in fact, CMEs resulting in significant radiation enhancements almost always have an associated flare. In addition, the x-rays emitted during solar flares can result to the loss of high frequency communication on commercial aircraft operations. A new paradigm for the forecast and nowcast of solar proton events occurrence and their characteristics has been developed and integrated into the Forecasting for Solar Particle Events and Flares (FORSPEF) tool. The prediction modules are based on reductive data-driven statistical schemes. The SEP forecast utilizes solar flare forecasts [Georgoulis, ESWW 2013] based on sophisticated analysis of active region magnetograms, while the SEP nowcast uses available real-time observations of solar surface and corona. Using for the first time newly cross-calibrated values of GOES/EPS energy channels (Sandberg et al GRL, submitted) we constructed a new extensive database of solar proton event characteristics based on the analysis of NOAA GOES proton flux measurements over three solar cycles including information on the parent solar activity. The predictions are given in terms of confidence levels for selected SEP characteristics (onset, peak flux time, peak flux, fluence, duration). Characteristic examples and recent validation results are presented. This work has been funded through the “FORSPEF: FORecasting Solar Particle Events and Flares”, ESA Contract No. 4000109641/13/NL/AK
Oral	9:15 am	SEPsFLAREs: Forecasting and Warning Prototype System of SEP Events and Solar Flares Supporting Space Launcher Operators
		García-Rigo, A¹; Núñez, M²; Qahwaji, R³; Ashamari, O³; Hernández-Pajares, M¹; Jiggens, P⁴; Hilgers, A⁴
		¹Ionospheric determination & Navigation based on Satellite & Terrestrial systems (IonSAT) research group of the Technical University of Catalonia (UPC); ²Space Weather Group of the University of Malaga (UMA); ³Space Weather Research Group of the University of Bradford (UOB); ⁴ESA Space Environments & Effects section (TEC-EES), ESA-ESTEC
		A web-based prototype system for predicting Solar Energetic Particle (SEP) events and Solar Flares for its use by space launcher operators (or any interested user) is being implemented in the frame of SEPsFLAREs project (see http://ionsat92.upc.es/SEPsFLAREs). This is an activity funded by ESA/ESTEC Space Environment (TEC-EES) section (see http://space-env.esa.int/index.php/news-reader/items/flare_sep.html) to be ended by November, 2014. As a first step, the requirements for Launch Operation Service (LAU) domain have been identified by iterating and refining those given in the Space Situational Awareness - Space Weather Customer Requirements Document (SSA SWE CRD). The system that is being developed aims to provide not only predictions of SEP events based on x-ray and proton data but also warnings with a longer forecast horizon thanks to using solar flare forecast data and additional information (for instance, the existence of a magnetic connection with the flaring region). Thanks to this approach, alerts on potential un-safe conditions will be issued in order to prevent from enhancements of solar high energy particles which impact spacecraft, such as the production of single event effects (SEEs) seen in launchers. The SEPsFLAREs Forecast Prototype System consists of three prediction modules: the Solar Flare Prediction Module, the SEP Occurrence and Onset Prediction Module and the SEP Flux Profile, Intensity and Duration Prediction Module. Part of the system is based on two existing predictive tools, the Automated Solar Activity Prediction (ASAP; see http://spaceweather.inf.brad.ac.uk/asap and [T. Colak & R. Qahwaji, Automated solar activity prediction: A hybrid computer platform using machine learning and solar imaging for automated prediction of solar flares, Space Weather, 7 (S06001), 2009]) and the SEP prediction algorithm (UMASEP; see http://spaceweather.uma.es/ and [Núñez, M. (2011), Predicting Solar Energetic Proton Events (E > 10 MeV), Space Weather, 9, S07003, DOI:10.1029/2010SW000640]), combined with new, additional developments. The system will also acquire data for solar flares nowcasting (including GSFLAI indicator and SISTED detector; see [Hernández-Pajares, M., A. García-Rigo, J.M. Juan, J. Sanz, E. Monte and A. Aragón-Ángel (2012), GNSS measurement of EUV photons flux rate during strong and mid solar flares. Space Weather, Volume 10, Issue 12, doi:10.1029/2012SW000826]). New developments focus on the merging of flare and SEP forecasts and the prediction of SEP event peak intensity and duration.
Oral	9:30 am	Solar Particle Events And Human Spaceflight
		Berger, T¹; Matthiä, D¹; Reitz, G¹
		¹German Aerospace Center
		The radiation environment encountered in space differs significantly from that on Earth both in composition and intensity. It consists mostly of highly energetic galactic cosmic ray ions from protons up to iron which cause radiation levels far exceeding the values that occupational radiation workers on Earth are exposed to. In Low Earth Orbit an additional radiation component is the trapped particles in the Radiation Belts, especially while the International Space Station is crossing the South Atlantic Anomaly. These two components are the main sources of the radiation environment inside the space station which consists of primary and secondary particles created by interactions with the station’s hull. In addition, contributions from Solar Particle Events have to be considered, especially during solar maximum and decreasing solar maximum conditions. These events could provide doses leading to acute radiation effects in astronauts. Further on, for a future human flight to Mars considering and mitigating the dangers of Solar Particle Events is essential for mission planning. This talk will give an overview of Solar Particle Events observed onboard the International Space Station and during the MSL mission on its flight to Mars and on the surface of Mars in comparison to model predictions. An emphasis will be put on the procedural impact of Solar Events on human space flight and operations.
Oral	9:45 am	Comparison of Codes Assessing Radiation Exposure of Aircraft Crew During Energetic Solar Particle Events
		Beck, P¹; Bottollier-Depois, J F²; Bütikofer, R³; Flückiger, E⁴; Fuller, N⁵; Latocha, M⁶; Mares, V⁷; Matthiä, D⁸; Rühm, W⁷
		¹Seibersdorf Laboratories; ²Institute for Radiological Protection and Nuclear Safety, IRSN; ³International Foundation High Altitude Research Stations Jungfraujoch and Gornergrat; ⁴University of Bern; ⁵Observatoire de Paris, LESIA; ⁶Seibersdorf Laboratories; ⁷Helmholtz Zentrum München, HMGU; ⁸German Aerospace Center, DLR
		The European Community Council Directive 96/29/EURATOM defines the basic safety standards for the protection of aircrew against the dangers arising from cosmic radiation. According to European Union legislation, this directive is binding to every country of the European Union and implemented by national law. Annual effective dose for aircrew members due to galactic cosmic radiation (GCR) range from about 0.2 to 5mSv, depending on flight routes and number of hours per year [1]. Investigations from literature show we cannot exclude that a single extreme solar cosmic radiation (SCR) event can cause an effective dose on a subsonic flight of up to several mSv in a worst-case scenario [2]. While we understand dose assessment procedures for GCR exposure of aircrew members well and assessed doses agree within 30% for the different models [3], the radiation exposure due to SCR events is still a matter of scientific research. In the presentation, we describe the status of investigation by the EURADOS Working Group WG11. We compare existing models and corresponding results for dose estimation at flight altitudes during SCR events. The results show that further research and verification of the codes, in particular by on-board measurements are necessary. References: [1] United Nations Scientific Committee on the Effects of Atomic Radiation, Sources and Effects of Ionizing Radiation, UNSCEAR Report 2008, Vol.1, Annex B, Exposures of the public and workers from various sources of radiation, 2008. [2] P. Lantos and N. Fuller, HISTORY OF THE SOLAR PARTICLE EVENT RADIATION DOSES ONBOARD AEROPLANES USING SEMI-EMPIRICAL MODEL AND CONCORDE MEASUREMENTS, Radiation Protection Dosimetry, 104, n°3, 199-210, 2003. [3] J.F. Bottolier-Depois, P. Beck, M. Latocha, V. Mares, D. Matthiä, W. Rühm, F. Wissmann, Comparison of Codes Assessing Radiation Exposure of Aircraft Crew due to Galactic Cosmic Radiation, EURADOS Report 2012-03, ISSN 2226-8057, ISBN 978-3-943701-02-9, 2012.

Highlighted poster	10:00 am	COMESEP and the SEP Forecast Tool
		Dierckxsens, M¹; Tziotziou, K²; Dalla, S³; Patsou, I²; Marsh, M³; Crosby, N¹; Malandraki, O²; Lygeros, N²
		¹Belgian Institute for Space Aeronomy (BIRA-IASB); ²IAASARS, National Observatory of Athens; ³Jeremiah Horrocks Institute, University of Central Lancashire
		The FP7 COMESEP (COronal Mass Ejections and Solar Energetic Particles: forecasting the space weather impact) project developed tools for forecasting geomagnetic storms and solar energetic particle (SEP) radiation storms. Here we present the SEP forecast tool which provides a prediction of the probability for an SEP event to occur near Earth following the real-time observation of an X-ray flare, and estimates the most likely impact if such an event would occur. The tool has been operational on the COMESEP alert system (http://www.comesep.eu/alert) since November 2013. Alerts are provided for proton storms with E>10 MeV and E>60 MeV in the form of a risk level, combining the probability and expected impact. The predictions are based on a statistical analysis of SEP events and their parent solar activity during Solar Cycle 23. The input parameters are the flare intensity and longitude, as well as the CME speed and width, if an observed CME can be associated with the flare. This information is also received through the COMESEP system. Alerts are based on the available information when triggered and are subsequently updated if more information becomes available. The forecast for the probability, the impact and risk level are evaluated on events from solar cycles 22 and 24. The effect of including flare location and CME parameters is also studied. The performance of the SEP forecast tool within the COMESEP alert system will be described. This work has received funding from the European Commission FP7 Project COMESEP (263252).
Highlighted poster	10:05 am	Multiplatform Observations of the Earth’s Particle Radiation Environment during the 17 May 2012 SEP Event
		Laurenza, M¹; Berrilli, F²; Del Moro, D²; Di Felice, V³; Gerontidou, M⁴; Kanellakopoulos, A⁴; Martucci, M³; Mavromichalaki, H⁴; Mergè, M³; Narici, L²; Plainaki, C¹; Sparvoli, R³; Storini, M¹
		¹IAPS/INAF; ²Department of Physics, University of Roma “Tor Vergata”; ³INFN Italian National Institute for Nuclear Physics, Tor Vergata Group; ⁴Nuclear and Particle Physics Department, Physics Faculty, National and Kapodistrian University of Athens
		The 17 May 2012 solar energetic particle (SEP) event, associated with a M5.1-class solar X-ray flare from AR11476 located at the western solar limb, produced the first Ground Level Enhancement (GLE) of the 24th solar activity cycle, also known as GLE71, recorded by the worldwide network of neutron monitors (NMs). The SEP event was also registered by numerous instruments on near-Earth satellites and spacecraft, including PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics), a unique instrument which provides accurate measurements in the energy range from a few hundreds of MeV/n up to hundreds of GeV/n. A joint analysis of the 17 May 2012 event, based on multiplatform observations of the Earth's radiation environment, is performed. The GLE71 NM data are used in the Neutron Monitor Based Anisotropic GLE Pure Power Law (NMBANGLE PPOLA) model (Plainaki et al. 2010, Sol. Phys., 264, 239), in order to obtain several characteristics of the related SEP event, such as the the rigidity spectrum, the spatial distributions of the primary solar protons at the top of the atmosphere and the time-evolution of the GLE source location. A comparison between the modeling results and the PAMELA and GOES observations is presented in the framework of assessing radiation levels and risk conditions in the Earth’s environment. Hence, measurements of the active particle detectors of the ALTEA (Anomalous Long Term Effects in Astronauts) experiment on board the International Space Station (ISS) are used to estimate the energy loss spectrum of the solar particles and evaluate the contribution to the total exposure of ISS astronauts to the SEP event.
Highlighted poster	10:10 am	Computation of Ionization Effect in the Earth Atmosphere During Major Ground Level Enhancements of Solar Cycle 2
		Mishev, A¹; Velinov, P²
		¹Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria; ²Institute for Space Research and Technology, Bulgarian Academy of Sciences, Sofia, Bulgaria
		Several strong ground level enhancement (GLE) events occurred during solar cycle 23 casing a significant ionization effect in the Earth’s atmosphere. At present, it is known that solar protons of relativistic energies following major solar eruptions cause an excess of ionization in the atmosphere and ionosphere, specifically in the polar region. Here we compute the ionization effect in the terrestrial atmosphere and ionosphere for various latitudes during the most-significant events of solar cycle 23, namely during GLE 59 on 14.07.2000, GLE 60 on 15.04.2001, GLE 69 on 20.01.2005 and GLE 70 on 13.12.2006. The computation of ion production rates is according previously developed numerical model for cosmic ray induced ionization, based on a full Monte Carlo simulations of atmospheric cascade. We apply direct simulation of atmospheric cascade with the CORSIKA 6.990 code using FLUKA 2011 and QGSJET II hadron generators and realistic atmospheric model considering the effect of seasonal atmospheric profile variations. The ion production rates during the event are computed on a reasonable time step, which allows high precision. The solar energetic particle spectra are considered according reconstructions on the basis of ground based measurements with neutron monitors. The time evolution of the ion rate production is explicitly considered. The short to medium time scale effect is estimated. The obtained results are discussed and compared. Тhey demonstrate the impacts of solar radiation events on the Earth's environment and can be useful not only for the solar system effects (planetary atmospheres) but for satellite operations, human space flights and civil aviation also.
Highlighted poster	10:15 am	Impact of an Extreme Space Weather Event on European Space Assets
& e-poster		Armiens, C
		European Commission - Joint Research Centre
		Our present society is increasingly dependent on technology for maintaining and improving its life standards. As a consequence, a large-scale failure of this technology could have devastating effects. To make things even more complex, systems are interconnected and interdependent between them, so the disruption of one could provoke a cascading effect on the others, leading to a general collapse of the underlying infrastructures. Space technology is not free from this risk. Telecommunications, navigation, weather forecast services, border surveillance and many others are examples of how human daily activities are dependent on satellites. Apart from these direct examples, there are other systems that depend on space technology in a more subtle way. Global navigation systems, besides localization, provide also very precise timing information. This clock is used for synchronization processes in the electric grid or the global financial markets, to mention just a couple of examples. Disruption of this synchronization signal for a few days, or a few weeks, could put the systems under considerable stress, the consequences of which are not clearly known. Also very dangerous is the fact that, sometimes, this dependency is even not known by the system operators, who therefore cannot have a backup solution ready. An impact assessment of an extreme space weather event on European space assets is currently being done at the European Commission's Joint Research Centre. The objective is to gain some knowledge about the consequences that such a low probability but high impact event would have on satellites. The study is focused on two of the main European space infrastructures, EGNOS and Galileo, and consists of three differentiated phases: • Definition of a benchmark extreme event. Two solar particle events with recurrence periods of 100 and 200 years have been defined. These long periods have been chosen since they are usually considered in risk assessment analysis. The particle fluence has been defined using the JPL model implemented in SPENVIS for solar proton events. The respective F30 values at geostationary orbit are 1.39e10 and 2.32e10 particles/cm2. • Impact assessment on existing or planned space infrastructures. Once the radiation storms have been defined, their potential impact on satellites will be analyzed. This study will make extensive use of SPENVIS in order to estimate ionizing dose, non-ionizing dose, damage to solar cells, single event effects and spacecraft charging of the previously defined storms. All these effects will then be compared with a normal year in orbit to assess the relative impact of one such extreme event with respect to background conditions. In addition to SPENVIS, tools like SEPEM, or indeed others, may also be employed. • Comparison with previous events. The last part of the impact assessment will consist of the study of previous events, like, for example, the Halloween storm. This event, which happened in 2003, is very interesting since, on the one hand, there is a complete data set of the amount of particles which came from the Sun and their energies, and, on the other hand, there were about 900 satellites in orbit that suffered consequences. The telemetries of all these satellites contain crucial information about the real effects of a very intense storm like this one. The support of manufacturers, operators and other organizations like the European Space Agency or Eumetsat will be vital in order to access all that wealth of data.
Highlighted poster	10:20 am	Solar Energetic Proton Nowcast for Low Earth Orbits
		Huston, S¹; Winter, L¹; Quinn, R¹
		¹AER, Inc.
		The NOAA-operated GOES satellites provide real-time monitoring of solar energetic particles from geosynchronous orbit. However, it is also necessary to assess the risk from high solar particle flux to satellites and spacecraft in low Earth orbit. Therefore, we developed a solar energetic proton nowcast that determines flux levels at a variety of altitudes.
Highlighted poster	10:25 am	Development of Solar Heavy Ion Models in the Frame of the ESA ESHIEM Project: Definition of Ion Abundances
		Varotsou, A¹; Samaras, A¹; Heynderickx , D²; Truscott, P³; Lei, F⁴; Jiggens, P⁵
		¹TRAD; ²DH Consultancy BVBA; ³Kallisto Consultancy; ⁴RadMod; ⁵ESA/ESTEC
		During Solar Energetic Particle (SEP) events, solar heavy ions (Z ≥2) constitute an important risk to satellite electronics. These particles can cause Single Event Effects (SEE) in onboard electronics leading to loss of data and even to temporary loss of satellite control. It is therefore important to build reliable models to describe these events including solar heavy ions. The main goal of the ESA ESHIEM project (Energetic Solar Heavy Ion Environment Models) is to build statistical solar heavy ion models to complement the already existing proton ones within the SEPEM server. In the frame of this project, data from the SIS instrument onboard the ACE spacecraft have been processed and analysed to provide abundances for 14 solar ions. Abundance ratios between solar heavy ions have been calculated for 18 SEP events from 1998 to 2013 which have good data coverage. Results show that these ratios vary from one event to another and that they are energy dependent. These results as well as abundance ratio variations during events will be discussed. Finally, comparisons with the currently used engineering solar heavy ion models PSYCHIC and CREME96 will be presented.

Oral	11:30 am	Modeling Radiation Impacts with Coupled CME-SEP Simulations
		Linker, J¹; Schwadron, N²; Torok, T¹; Gorby, M²; Downs, C¹; Lionello, R¹; Mikic, Z¹; Riley, P¹
		¹Predictive Science Inc.; ²University of New Hampshire
		Solar energetic particles (SEPs) are an important space weather phenomena. The largest SEP events are typically associated with M or X-class solar flares and fast coronal mass ejections (CMEs). Given a strong eruptive event, many factors determine whether or not SEPs reach Earth or any other location in the heliosphere, including how strong the particle acceleration is, whether the particles can reach open field lines, and the connectivity of those field lines into the heliosphere. We are developing the capability to simulate SEP events by combining MHD simulations of CMEs with models of SEP acceleration and transport. The CME simulations start from realistic models of the corona developed with CORHEL (Corona-Heliosphere), a suite of models and tools for characterizing the solar and heliospheric environment for specific time periods. The time evolving MHD fields are used to drive solutions of the focused transport equation performed with the Energetic Particle Radiation Environment Module (EPREM). EPREM is a component of EMMREM (Earth-Moon-Mars Radiation Environment Module), which can provide dose estimates for simulated SEP fluxes. We demonstrate this capability for a simulation of an idealized event, and we discuss our progress on a preliminary simulation of the July 14, 2014 (Bastille Day) event.
Oral	11:45 am	SEP Modeling and Forecasts Based on the ENLIL Global Heliospheric Model
		Mays, L¹; L., Janet²; Odstrcil, D³; Z., Yihua¹; Kuznetsova, M¹
		¹NASA/GSFC; ²UCB/SSL; ³GMU
		Understanding gradual SEP events (often driven by CMEs) well enough to forecast their properties at a given location requires a realistic picture of the global background solar wind through which the shocks and SEPs propagate. The global 3D MHD WSA-ENLIL model (Odstrcil et al., 2004) provides a time-dependent background heliospheric description, into which a cone-shaped CME can be inserted. It is clear from our preliminary runs that the CMEs sometimes generate multiple shocks, some of which fade while others merge and/or strengthen as they propagate. In order to completely characterize the SEP profiles observed at various locations with the aid of these simulations it is essential to include all of the relevant CMEs and allow enough time for the events to propagate and interact. From ENLIL v2.8 simulations one can extract the magnetic topologies of observer-connected magnetic field lines and all plasma and shock properties along those field lines. ENLIL “likelihood/all-clear” forecasting maps provide expected intensity, timing/duration of events at locations throughout the heliosphere with “possible SEP affected areas” color-coded based on shock strength. Accurate descriptions of the heliosphere, and hence modeled SEPs, are achieved by ENLIL only when the background solar wind is well-reproduced and CME parameters are accurate. ENLIL derived information is also useful to drive SEP models such as the Solar Energetic Particle Model (SEPMOD) which calculates the time series of ~10-100 MeV protons at a specific observer location using a passive test particle population (Luhmann et al. 2007, 2010). Results from SEP models driven by ENLIL can further be used for radiation dose calculations for interplanetary missions. In this presentation we demonstrate SEP event modeling which utilizes routine ENLIL runs important for space weather forecasting and research. Making SEP models available for research and operational users is one of Community Coordinated Modeling Center's (CCMC) top priorities. Heliospheric model outputs are a necessary ingredient for SEP simulations. The CCMC is making steps towards offering a system to run SEP models driven by a variety of heliospheric models available at CCMC such as the ones described in this presentation.
Oral	12:00 pm	Economic Impact and Effectiveness of Radiation Exposure Mitigation Measures during a Ground Level Enhancement
		Matthiä, Daniel¹; Meier, Matthias¹; Schaefer, Martin¹; Häggström, Ingemar²; Ogawa, Y³; Tetsuo, M³; Buchert, S⁴; Nozawa, S⁵
		¹German Aerospace Center (DLR); ²EISCAT Scientific Association; ³National Institute of Polar Research; ⁴Swedish Institute of Space Phyics; ⁵Nagoya University
		In addition to the omnipresent radiation exposure from galactic cosmic rays and their secondary particles at aviation altitudes, aircrew and passengers may receive an increased dose from solar cosmic rays during ground level enhancements. In many cases, reducing the altitude or changing the route to lower latitudes are measures generally applicable to immediately reduce the dose rate and the corresponding total dose on a flight. In practice, however, taking such action necessarily leads to deviations from the operational flight plan and the consequential, additional fuel consumption constrains the mitigating action and also increases operational costs. Using an aircraft performance tool and the Monte-Carlo based PANDOCA model for the calculation of the radiation exposure we investigate in a case study how mitigation procedures might have affected the dose rates and the total radiation exposure on a transatlantic flight during the ground level event of December 13th 2006. The reduction in radiation exposure achievable for a realistic flight scenario is examined in the context of the related additional fuel consumption and possible flight delay.
Oral	12:15 am	AVIDOS 2.0 – Current Developments for the Assessment of Radiation Exposure at Aircraft Altitudes Caused by Solar Cosmic Radiation Exposure
		Latocha, M¹; Bütikofer, R²; Beck, P¹
		¹Seibersdorf Laboratories; ²University of Bern and International Foundation High Altitude Research Stations Jungfraujoch and Gornergrat
		AVIDOS (aviation dosimetry) is a web-based service of the Seibersdorf Laboratories federated with ESA’s Space Weather portal, accessible under: http://swe.ssa.esa.int/web/guest/avidos-federated. It is an informational and educational online software for the assessment of the radiation exposure at flight altitudes caused by galactic cosmic radiation. It estimates route doses for flights between any two locations. It also provides a comparison of assessed exposure with natural background radiation on Earth. Since the current version of AVIDOS does not take into account ionizing radiation impact of the occasional energetic solar cosmic ray events, we are extending AVIDOS for the provision of dosimetry at aircraft altitudes due to solar radiation exposure. We will present the status of the developments. The development of AVIDOS was partly supported by the European Space Agency (ESA Contract: No. 44000105734/12/D/MRP), the Austrian Federal Ministry of Transport and Innovation, and the Austrian Agency for Aviation and Space (ALR) as part of the Austrian Promotion Agency, FFG.
Oral	12:30 pm	Two High-Energy (>300 MeV) Proton Fluence Models Based on Ground-Based and Spacecraft Data
		Vainio, R¹; Vuori, A¹
		¹University of Turku
		We consider two probabilistic fluence models based on ground-level enhancement (GLE) observations of solar energetic particle (SEP) events and spacecraft observations of proton events at energies above 300 MeV. For the first model, we use integral rigidity spectra and times of occurrence of all GLEs of Solar Cycles 19-23 (GLEs observed in 1956-2006). For the second model we restrict ourselves to Cycles 21-23 but include not only GLEs but also smaller events that were observed above 300 MeV only by satellites. Both models use integral rigidity spectra of the events fitted to a broken power-law function (Band et al. 1993, ApJ 413:281; Tylka & Dietrich 2009, Proc. 31st Internat. Cosmic Ray Conf., paper #273). We also combine closely spaced (correlated) events into multi-event episodes, which are then assumed to follow Poisson statistics. We determined the waiting-time distributions, the fluence distributions, and the distributions of event occurrence times over an average solar activity cycle based on these datasets. We then constructed probabilistic fluence models for >300 MeV protons based on these distributions. Both mission integrated and worst-case-event fluences were considered. In the presentation, we will compare the results with existing probabilistic fluence models and against each other.
Oral	12:45 pm	Theoretical Model of SEP Radiation Hazard Forecasting on the Basis of One-Minute Neutron Monitor and Satellite Data in Real Time
		Dorman, L
		Israel Cosmic Ray and Space Wearther Center of Tel Aviv University, Israel Space Agency and Golan Research Institute, Israel; IZMIRAN, Russia
		The model is based on one-minute NM data (for the high energy region) and one-minute satellite (e.g. GOES) data available through the internet in different energy ranges (from 4 MeV up to 500 MeV). First, we develop a program that automatically determines the beginning of an SEP by continuously analysing NM and satellite data. After the start of an SEP, by using NM data and data in the four largest energy ranges, we determine the SEP energy spectrum in the high energy region. After a few (at least 4) minutes, we try to solve the inverse problem of SEP generation and propagation and estimate on the basis of determined changes of the SEP energy spectrum in time the following main parameters: the time of ejection into the solar wind, the energy spectrum of SEP generation, and the bi-metric diffusion coefficient dependent on energy and distance from the Sun. With each new minute of observation, we obtain the results of the inverse problem solution more and more exactly. For each new minute of observation we then solve the direct problem (using estimated values of time of ejection into solar wind, energy spectrum of SEP generation, bi-metric diffusion coefficient) and determine the expected SEP fluxes in different energy ranges not only during observed time (to check the solution of the inverse problem), but also the expected SEP fluxes in the near future for the forecasting of the expected total radiation hazard in space, in the magnetosphere, and in the atmosphere for spacecraft, satellites, and airplanes.

More Posters

The numbering on this page might differ from the numbering on the page with the short overview without abstracts.

7	FORSPEF: An Operational Service for the Prediction of Solar Energetic Particle Events and Flares
	Anastasiadis, A¹; Sandberg, I¹; Papaioannou, A¹; Georgoulis, M²; Tsiropoula, G¹; Tziotziou, K¹; Katsiyannis , A C³; Jiggens, P⁴; Hilgers, A⁴
	¹National Observatory of Athens; ²Academy of Athens; ³Solar-Terrestrial Center of Excellence, SIDC, Royal Observatory of Belgium; ⁴ESA/ESTEC
	Solar Energetic Particle (SEP) events resulting from intense eruptive events such as solar flares and coronal mass ejections (CMEs), pose a significant threat for both personnel and infrastructure in stormy space-weather conditions. Of particular concern is the high rate of single event effects on-board spacecraft launchers which can be brought about by large increases in the radiation environment as a result of such solar activity. A new web-based service for the prediction of solar eruptive and energetic particle events is presented. FORSPEF (Forecasting Solar Particle Events and Flares) is designed to perform forecasts and nowcasts of the occurrence and the characteristics of solar flares and SEP events. The service is targeted to launch operators and to the space-weather community. For the prediction of solar flares, an assessment of potentially flaring active-region magnetic configurations is utilized based on sophisticated analysis of a large number of magnetograms of solar active regions. For the prediction of SEP events, a novel reductive statistical scheme is implemented upon a newly constructed database that includes characteristics of SEP events and their parent solar events. The new comprehensive catalogue of SEP events includes solar associations in terms of flare (magnitude, location) and CME (velocity) characteristics, as well as radio burst (Type III and Type II) signatures. The SPE prediction scheme utilizes the output of solar flare forecast, while the SPE nowcast uses real time observations of the solar surface and solar corona. We present and discuss the architecture of the prediction tools integrated in the FORSPEF service as well as the outputs related to the warning of possible solar flares and the prediction of the onset, flux profile and duration of SEP events. The FORSPEF web-based service is expected to be fully operational within the following months. This work has been funded through the “FORSPEF: FORecasting Solar Particle Events and Flares”, ESA Contract No. 4000109641/13/NL/AK
8	Monte Carlo Simulations of SEP Acceleration in Coronal Shocks
	Afanasiev, A¹; Vainio, R¹
	¹University of Turku
	Diffusive shock acceleration is widely accepted as the main mechanism responsible for acceleration of particles in the so-called gradual solar energetic particle (SEP) events. One of the key components of this mechanism is the foreshock, a limited spatial region ahead of the shock, hosting enhanced Alfvénic turbulence generated by energetic particles themselves. Through wave-particle interactions, the dynamics of particle acceleration is coupled to the dynamics of the foreshock development. This is especially important for the shock travelling in the corona where particles are accelerated to the highest energies but the foreshock may not be in the steady state yet. Monte Carlo simulations have proved to be a fruitful approach in constructing time-dependent dynamical models of the foreshock. The foreshock model developed in the University of Turku (Finland), i.e., the CSA (Coronal Shock Acceleration) Monte Carlo code, relies on the quasi-linear approximation for wave-particle interactions and applies a simplified way (neglects the pitch-angle dependence in the resonance conditions) to model the interactions. However, recent results on the effect of retaining the pitch-angle dependence on the Alfvén wave growth imply that the more accurate treatment of wave-particle interactions should modify the modeled foreshock development process. We, therefore, have developed a new, more accurate Monte Carlo model of the foreshock evolution. Here we present the model and first simulation results in comparison with those of the CSA model.
9	Iron-Rich Solar Particle Events Measured by SOHO/ERNE
	Raukunen, O¹; Valtonen, E¹; Vainio, R¹
	¹University of Turku
	We have surveyed the SOHO/ERNE data from the beginning of the mission until the end of 2013 for solar particle events with enhancements in the Fe/C and Fe/O intensity ratio in energy ranges 10-18 MeV per nucleon and 45-90 MeV per nucleon. We have studied the relative abundances and spectral properties of heavy ions (C, N, O, Ne, Mg, Si, S, Ca, Fe) in these events. We have also studied the possible correlations of the heavy-ion enhancements with properties of associated flares and coronal mass ejections, event sizes and level of solar activity. In addition, we have compared the properties of heavy ions in these events with those of ~68 MeV proton events in the SEPServer catalogue (Vainio et al. 2013), and the so-called impulsive events (Mason et al. 2004, Reames & Ng 2004). Vainio R, Valtonen E, Heber B, Malandraki O, Papaioannou A, et al.: The first SEPServer event catalogue - ~68-MeV proton events observed at 1 AU in 1996-2010. J. Space Weather Space Clim., 2013, 3, A12 Mason G, Mazur J, Dwyer J, Jokipii J, Gold R, Krimigis S: Abundances of heavy and ultraheavy ions in 3He-rich solar flares. ApJ, 2004, 606, 555 Reames D, Ng C: Heavy-element abundances in solar energetic particle events. ApJ, 2004, 610, 510
10	Solar Energetic Particles and Active Regions on the Sun
	Bronarska, K
	Astronomical Observatory of the Jagiellonian University
	The relationship between active regions (ARs) and solar energetic particles (SEP) is studied. For this purpose a statistical analysis of 115 SEP events and especially 22 ground level enhancements (GLE ) asociated with ARs was carried out. I considered the relationship between features of SEP such as proton flux or velocity and ARs characterized using the McIntosh Sunspot Classification Scheme (MSCS) . I found that active regions which are responsible for production of the highest streams of particles have complex magnetic field. Solar energetic particles originate from the ARs consisting of the large bipolar structures (C, D, E, F according to McIntosh classification scheme) with asymmetric penumbrae around the largest spots and many smaller spots in the group . The probability of launching of strong proton flux increases together with increase of the complexity and size of ARs. If solar energetic particles are directed toward the Earth they could be geo-effective so this result could be useful for forecasting of space weather.
11	STEREO Observations of the Longitudinal Distribution of Solar Energetic Particles
	Gómez-Herrero, R¹; Heber, B²; Dresing, N²; Klassen, A²; Lario, D³; Agueda, N⁴; Malandraki, O⁵; Blanco, J J¹; Rodríguez-Pacheco, J¹
	¹SRG - University of Alcalá; ²IEAP, University of Kiel; ³The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD; ⁴Universitat de Barcelona; ⁵IAASARS, National Observatory of Athens
	The orbital configuration of the STEREO mission is ideal for the study of Solar Energetic Particle (SEP) events from a multi-point perspective. The combination of remote-sensing and in-situ observations by STEREO and by spacecraft orbiting near-Earth such as SOHO, ACE and Wind provides the opportunity to determine how the SEP properties (such as peak intensities, anisotropies and onset-time delays) vary as a function of the angular separation between the observer’s magnetic footpoint and the source active region at the Sun. We present a review of the main findings achieved by STEREO in this subject, discussing the physical scenarios proposed to explain the observations and their implications for Space Weather. We also present case-studies showing exceptionally broad particle spread around the Sun, such as the SEP events observed on 17 January 2010 and 3 November 2011.
12	Prediction of GLE´s: Delimitation of Time Intervals for the Possibility of Occurrence During Solar Cycles 24-25
	Perez-Peraza, J¹; Juarez-Zuñiga, A¹; Alvarez-Madrigal , M²
	¹Instituto de Geofísica, Universidad Nacional Autónoma de México; ²ITESM, Puente
	It is well known that the Relativistic Solar proton events have harmful effects on satellites, gas and electric installations at high latitudes, and so on, with subsequent economical losses. It is usually assumed that the occurrence of these kinds of events (Ground Level Enhancements) is of a stochastic nature: for instance, 13 GLE’s in the period of July 1989 to June 1991, and not a single event from the end of December, 2006 up to the middle of May, 2012. There have been several attempts to forecast Energetic Solar Particles (ESP), some of them including GLE´s, but these efforts were addressed to Alerts in Real Time, some minutes before or even during the course of the events. Usually the aim of these proposals is to estimate the flux of non relativistic protons, proceeding a GLE. Here we present a method to predict GLE’s , with months and even years before their occurrence: the method is based on the combination of spectral analysis techniques (wavelet), fuzzy logic and statistical analysis. The method allows for delimiting time windows where GLE’s will not occur, and time windows of possible occurrence. Applying our method 70 GLE’s, since February of 1942 (the first registered GLE) up to the event of December, 2006 , we found that their occurrence coincide with some of the predicted windows for the specific GLE being considered. Therefore, we proceed to predict event 71 that occurred on May 17, 2012. Also, we predict that the next event will take place around September 2014, Furthermore, we predict possible dates for the last event of the present solar cycle, and the first and last GLE’s of solar cycle 25. Our results point against the randomness of GLE’s ocurrence.
13	Forbush Effects and Precursors: Forecasting Strong Shock Waves using one Hour CR Data
	Dorman, L¹; Applbaum, D S²; Ben Israel, I²; Dai, U²; Kazantsev, V²; Kozliner, L²; Pustil'nik, L²; Sternlieb, A²; Zukerman, I²
	¹Israel Cosmic Ray and Space Wearther Center of Tel Aviv University, Israel Space Agency and Golan Research Institute, Israel; IZMIRAN, Russia; ²ICR&SW, Tel Aviv University
	Cosmic ray (CR) Forbush effects and precursors are important for space weather forecasting of phenomena that pose dangers to satellite electronics and other technologies even on the ground. We select Forbush effects observed on Mt Hermon. Then, using data from other stations, we construct for each event diagrams that show precursor effects using the method of ring stations. These precursor effects can be used for forecasting big magnetic storms. We also performed some statistical analysis of the obtained ring station diagrams and discuss the possibility of using the described method in a real time scale.
14	Multiplicity in Neutron Monitor: Single Particle vs Shower
	Balabin, Y
	Polar Geophysical Institute
	There are two ways to describe multiplicity generation in a neutron monitor (NM). The first one could be called “single particle origin”. It is based on the suggestion that a single very high energetic particle (nucleon) produces a great many (up to thousands) secondary neutrons in the lead shield of NM. It is conventional viewpoint on multiplicity. The second one could be called “shower origin”. It based on the assumption that a shower of energetic particles covers NM. Due to out fast recording system developed in Polar Geophysical Institute fine temporal and spatial structures of multiplicity can be study. These structures modify fluently along multiplicity number M growth, but differences between M < 10 and M > 40 become already significant. And fine structures of large multiplicity (M > 40) conform to the shower origin. Multiplicity structures on Barentsburg NM with having original design give clear and unambiguously answer: multiplicity M > 40 can be only generated by the shower.
15	Line of Special Neutron Monitors: Barentsburg, Apatity, Baksan
	Balabin, Y¹; Vashenyuk, E¹; Dzhappuev, D²; Gvozdevsky, B¹; Germanenko, A¹
	¹Polar Geophysical Institute; ²Institute of nuclear Research;
	Neutron monitors (NM) at the stations Barentsburg (arch. Spitzbergen), Apatity (Murmansk reg.) and Baksan (Northern Caucasus) have new rapid recording system. New amplifier-discriminators developed in Polar Geophysical Institute were set. Also detecting tubes of NM were tested and calibrated with help of a weight magnitude analyzer. NMs have been equipped with a rapid registration system. The system records time of each pulse coming with 1 microsecond accuracy. With help of special processing of the data it is possible to detect, separate and investigate different fast phenomena or transform the data to various forms. For example, the "large dead time" mode now realized via soft processing against hardware earlier. It is possible to get "a posteriori" NM data with any time resolution too. It is used universal time and one can look at the NM count data with the same accuracy – 1 mcs.
16	Spectral Shape of the Energy Spectrum for SEP Events
	Laurenza, M¹; Consolini, G¹; Storini, M¹; Damiani, A²
	¹IAPS/INAF; ²Agency for Marine-Earth Science and Technology
	An accurate representation of the energy spectrum of Solar Energetic Particle (SEP) events is essential to characterize the interplanetary radiation environment. Several spectral laws have been proposed in the past, such as power law, power law modulated by an exponential, broken power law. Here, we examine the spectral characteristics of some selected SEP events, as obtained through particle data from different spacecraft (ACE, ERNE, STEREO). In particular, we investigate the evolution of the kinetic energy spectra of SEP events through the Shannon’s differential entropy during the different phases of the selected events, as proposed by Laurenza et al. 2012 [Astrophys. Space Sci. Trans., 8, 19]. The spectral features are found to be consistent with a shape similar to the Weibull density distribution, both during the main phase of the SEP events and over their whole duration. Comparison of results obtained for energetic particles accelerated at corotating interaction regions (CIRs) and transient-related interplanetary shocks are also presented in the framework of shock acceleration.
17	Modelling Large SEP Events with the Shock-and-Particle Model Approach
	Aran, A¹; Pomoell, J²; Rodríguez-Gasén, R¹
	¹Universitat de Barcelona; ²Katholieke Universiteit Leuven
	During the FP7 Spacecast Project we have upgraded the shock-and-particle (SaP) model for the description of gradual solar energetic particle (SEP) events. The SaP model is the physical model upon which the space weather oriented tools SOLPENCO and SEPEM/SOLPENCO2 have been constructed. This model combines the simulation of the propagation of a CME-driven shock (from ~ 4 solar radii) and the simulation of the transport of particles along the interplanetary magnetic field (IMF) line connecting the shock front and the observer. We assume that the shock-accelerated particles escaping from the shock are injected at the point in the shock front intersected by this IMF line, i.e., at the cobpoint. The method developed permits us to perform simulations of a virtual armada of spacecraft scanning different regions of the expanding interplanetary shock front and of the 0.5 -- 200 MeV proton intensity-time profiles to be measured by such spacecraft. A semi-empirical relation between the injection rate of shock-accelerated particles, Q, and the jump in speed across the shock, VR, was derived from the modelling of several SEP events. Such a relation, a.k.a. the Q(VR) relation, is the basis of the two versions of the SOLPENCO tools since it permits to obtain synthetic SEP events. This is important for the development of software tools for the prediction of peak intensities, fluences and proton intensity-time profiles of SEP events for energies relevant to space weather. In order to further study the range of applicability of this relation, we are performing simulations of large (and extended) SEP events using the current multi-spacecraft capability provided by the combination of the STEREOs and near-Earth measurements. We present here the analysis and modelling of one of these SEP events that occurred on the 22nd of September 2011. Specifically, we describe the in-situ (plasma and particle) measurements by different near-Earth spacecraft and by STEREO A and B spacecraft, and we analyse the solar activity originating the observed particle enhancements. We present the performance of the shock-and-particle model and discuss the correlation obtained between Q and the plasma parameters at the shock front, such as VR.
18	SPARX: a Propagation based Modelling System for Solar Energetic Particle Radiation Space Weather Forecasting
	Marsh, M¹; Dalla, S¹; Laitinen, T¹; Dierckxsens, M²; Crosby, N²
	¹University of Central Lancashire; ²Belgian Institute for Space Aeronomy
	We present SPARX (Solar PArticle Radiation Space Weather [SWx]) a new modelling system simulating the propagation of Solar Energetic Particles for space weather purposes. SPARX incorporates a fully 3D model, using a full-orbit test particle approach, to simulate the propagation of solar energetic particles (SEPs) from the Sun to any given location in the heliosphere. The model is able to describe particle transport across the magnetic field and includes the effect of drifts. The SPARX system can forecast the time dependent particle flux within various energy ranges and output parameters of interest for space weather such as maximum flux, onset time, peak time and duration of the SEP event. SPARX is integrated within the SEP Forecast component of the EU FP7 COMESEP project (see poster by Dierckxsens et al. and www.comsep.eu). Within the COMESEP framework SPARX forecasts the near-Earth 10-minute averaged integral proton flux profiles in the E>10 MeV and E>60 MeV ranges, comparable to those supplied by the GOES spacecraft. We describe the methodology behind the modelling approach and forecasting system, within an operational space weather context, and present examples of system output. This work has received funding from the European Commission FP7 Project COMESEP (263252).
19	Drift Induced Deceleration in SEP Propagation
	Dalla, S¹; Marsh, M¹; Laitinen, T¹
	¹University of Central Lancashire
	Accurate forecasting of SEP fluxes requires modelling of particles' propagation through the interplanetary magnetic field. Drifts associated with the gradient and curvature of the Parker spiral magnetic field have been known for many years to play an important role in galactic cosmic ray transport, but have generally been neglected in SEP modelling. Recently it has been shown that drifts are important in the propagation of SEPs, their effect being particularly strong for partially ionised heavy ions and for protons at the high energy end of the SEP range [Marsh et al 2013, Dalla et al 2013]. As a result of drifts, SEPs experience a displacement from the field line on which they were originally injected, i.e. cross field transport. An important consequence of drift motion is that particles move in the direction of the solar wind electric field, experiencing an energy change which is in most cases a deceleration. We show that this phenomenon is not included in the standard treatment of adiabatic deceleration for SEPs [Ruffolo (1995)] and quantify its effect through full orbit test particle simulations of protons of initial energy 1 MeV, 10 MeV, 100 MeV and 1 GeV. The combined effect of adiabatic and drift induced deceleration produces a large energy change in the observer's frame of reference after four days: a decrease of between 35 and 90% of the initial kinetic energy for protons injected at 1 MeV, and between 20 and 55% for those injected at 100 MeV. Thus the effect of drift as measured in terms of kinetic energy change is very significant even for low energy protons. We discuss implications of this finding on measured profiles of SEPs and on forecasting models.
20	Event-oriented MHD Simulations of Global Coronal Shocks: Investigating the Evolution of Shock Obliquity and Density Compression
	Pomoell, J¹; Poedts, S²
	¹CmPA, KU Leuven; ²KU Leuven
	The production of large, space weather - relevant Solar Energetic Particle (SEP) events is intimately linked to eruptions of fast coronal mass ejections (CMEs) that are capable of driving strong shocks. Analysis of remote multi-wavelength observations as well as in-situ particle data have shown that the release of high-energy particles occurs low in the corona, already at heliocentric distances of a few solar radii. A detailed knowledge of the nature of the shock launched by the CME low in the corona is needed in order to assess the viability of shock acceleration as a mechanism to explain the prompt particle acceleration. In this work, we present event-oriented global three-dimensional magnetohydrodynamic simulations of shocks launched by an erupting CME. We focus in particular on determining the evolution of the characteristics of the global coronal shock wave, such as the the shock obliquity angle and density compression ratio, and discuss the implications for the generation of solar energetic particle events. Furthermore, we discuss the applicability of a combined PFSS and spherical shock model for use in characterizing the shock evolution.
21	Simulation of Particle-Shock Interaction with Nontrivial Shock Profiles
	Ganse, U¹; Vainio, R²
	¹University of Helsinki; ²University of Turku
	Interactions of particles with shocks is a central process in space weather events, as it occurs in both emission of gradual SEP events, as well as in any encounter of particles with the earths magnetosphere. Analytic models of shocks typically model these either as infinitely sharp discontinuous flows that jump from up- to downstream conditions, or as adiabatic changes from one state to the other, leading to conservation of adiabatic invariants. Both cases neglect the effects of any kind of kinetic-scale structure typically visible in in-situ observations. Using a kinetic-scale testparticle simulation code, we are studying the effects of foreshock waves, overshoots, finite shock widths and variations in cross-shock potential on resulting velocity distribution functions of both transmitted and reflected particle populations, showing significant deviation from simple loss-cone distributions.
22	GLE60 & GLE71 Modeling and SEP Properties using Different Magnetospheric Models and Ground-Based Data
	Mavromichalaki, H¹; Kanellakopoulos, A¹; Plainaki, C²; Laurenza, M²; Gerontidou, M¹; Storini, M²; Andriopoulou, M³
	¹National and Kapodistrian University of Athens; ²INAF-IAPS; ³Space Science Research Institute
	The use of different magnetospheric field models can influence the derivation of the relativistic SEP properties when modeling ground level enhancement (GLE) events. As case study, we examine the event of 2001 April 15 (GLE60), occurred at the maximum of the solar cycle 23, and the one of 2012 May 17 (GLE71), i.e., the first ground level enhancement of the solar cycle 24 after 11 years. They were both registered by the ground-based neutron monitor detectors. By using the Tsyganenko89 (T89) and Tsyganenko96 (T96) magnetospheric models we calculate the trajectories of the arriving SEPs and their intersection with the near-Earth environment for the two GLE events. We show that for every ground-based neutron monitor location there is a specific viewing region depending on the assumed magnetospheric configuration. Moreover, by applying the Neutron Monitor Based Anisotropic GLE Pure Power Law (NMBANGLE PPOLA) model on the GLE NM data, we derive the properties and the spatial distribution of the arriving SEP flux at the height of about 20 km. Finally, we examine the dependence of the results on the used magnetic field models and evaluate their range of validity.