Session 1 - Solar Energetic Particle Events: Measurement, Modelling, Forecasting and Impact
Piers Jiggens (European Space Research And Technology Centre), Mark Dierckxsens (BIRA-IASB), Daniel Heyderickx (DH Consultancy), Mike Marsh (Met Office), Rami Vainio (University of Turku)
Monday 14/11, 14:30 -18:30
The Solar Energetic Particle (SEP) environment has a critical physical impact on industry sectors such as civil aviation, human space flight, satellite design and operations. This session aims to encourage an environment of dialogue and knowledge exchange between stakeholders with a vested interest in solar energetic particle (SEP) events. Historically, measured SEP data was obtained from riometers and balloon flights, later came the era of neutron monitors and with the space age came direct in-situ observations. Different data sources come with their own strengths and weaknesses, clarity and caveats. Spacecraft designers and operators, manned aircraft and spacecraft flight operators, space weather forecasters and scientists can benefit greatly from long-term, carefully processed data sets and the models derived from them taking advantage of different data sources. This session welcomes contributions on SEP data, models, operational forecasting / alerting and effects. Regarding data, contributors are encouraged to place focus on derived flux and dose levels and to give comparisons with other data where available. Models in this context cover the propagation of particles through the interplanetary medium, magnetic fields and material shielding and can have implications for forecast and/or long-term predictions, contributors are encouraged to explore the impact of different data sources and the impact of models for defined users. SEP effects include ionizing and non-ionizing dose contributions, short-term single event effect rates (SEEs), contributions to non-ionising dose and human dose effects. Contributions on effects should focus on the impact of variability in the SEP environment. Regarding forecasting and alerting, the focus will be on communicating the outputs and user requirements of models, operational forecasting and end users concerned with the impact of SEP events. There is a significant need for the development of forecasting and alert systems for SEP radiation events. The outputs of these tools are intended to inform the However, such models, tools and research are often developed without the direct involvement of the end users such as operational forecasters and the affected sectors. Therefore, it is not always clear what parameters from space weather research/models are desired by users concerned with SEP impact.
Monday November 14, 16:00 - 17:00, Poster AreaTalks
Monday November 14, 14:30 - 16:00, Ridderzaal
Monday November 14, 17:00 - 18:30, RidderzaalClick here to toggle abstract display in the schedule
Talks : Time scheduleMonday November 14, 14:30 - 16:00, Ridderzaal
Monday November 14, 17:00 - 18:30, Ridderzaal
|14:30||SEP modeling based on the ENLIL global heliospheric model||Mays, M et al.||Invited Oral|
| ||M. L. Mays[1,2], J. G. Luhmann, D. Odstrcil, H. M. Bain, Y. Li, C. O. Lee, N. A. Schwadron, M. J. Gorby, Lan Jian[6,2], M. M. Kuznetsova|
| ||Catholic University of America; NASA Goddard Space Flight Center; Space Sciences Laboratory, University of California, Berkeley; George Mason University; University of New Hampshire; University of Maryland|
| ||Understanding gradual SEP events 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 provides a time-dependent background heliospheric description, into which a spherical shaped CME can be inserted. Successive CMEs can interact and merge as they propagate in the heliosphere and the particles accelerated in these shocks can result in complex SEP events. Heliospheric models provide contextual information of conditions in the heliosphere, including the background solar wind conditions and shock structures, and are used as input to SEP models, providing an essential tool for understanding SEP properties. ENLIL simulates solar wind parameters and additionally 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. ENLIL simulations also drive SEP models such as the Solar Energetic Particle Model (SEPMOD) (Luhmann et al. 2007, 2010) and the Energetic Particle Radiation Environment Module (EPREM) (Schwadron et al., 2010). SEPMOD injects protons onto a sequence observer field lines at intensities dependent on the connected shock source strength which are then integrated at the observer to approximate the proton flux. EPREM couples with MHD models such as ENLIL and computes energetic particle distributions based on the focused transport equation along a Lagrangian grid of nodes that propagate out with the solar wind. The coupled SEP models allow us to derive the longitudinal distribution of SEP profiles of different types of events throughout the heliosphere. In this presentation we demonstrate case studies of SEP event modeling at different observers based on WSA-ENLIL+Cone simulations.
The Community Coordinated Modeling Center (CCMC) will make SEP models available for research and operational users soon. 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.|
|14:55||Near realtime forecasting of MeV protons on the basis of sub relativistic electrons||Heber, B et al.||Invited Oral|
| ||B. Heber, J. Labrenz, P. Kühl, J. Marquardt, C. Sarlanis, O. Malandraki, A. Posner|
| ||IEAP / CAU Kiel, Extraterrestrische Physik, Kiel, Germany; ISNet, Athens, Greece; National Observatory of Athens, IAASARS, Athens, Greece; NASA Headquarters, Heliophysics, Washington DC, U.S.A.|
| ||A major impact on human and robotic space exploration activities is the sudden and prompt occurrence of solar energetic ion events. In order to provide up to an hour warning time before these particles arrive at Earth, relativistic electron and below 50 MeV proton data from the Electron Proton Helium Instrument (EPHIN) on SOHO were used to implement the 'Relativistic Electron Alert System for Exploration (REleASE)'. It has been demonstrated that the analysis of relativistic electron time profiles provides a low miss and false alarm rate.
High Energy Solar Particle Events foRecastIng and Analysis (HESPERIA) is a project funded within the European Union's Horizon 2020 research and innovation program (PROTEC-1-2014 Call: Space Weather). Within this project the REleASE forecasting scheme was rewritten in the open access programming language PYTHON and will be made public. As a next step, we have analyzed the possibility to also use, along with relativistic electrons (v > 0.9 c) provided by SOHO, near-relativistic (v <0.8 c) electron measurements from other instruments like the Electron Proton Alpha Monitor (EPAM) aboard the Advanced Composition Explorer (ACE). This would prove to be particularly useful during periods that SOHO does not provide continuous near real-time data. We show that the ACE/EPAM observations can be adapted to the REleASE forecasting scheme to provide reliable SEP forecasts. A comparison of measured and forecast proton intensities by SOHO/EPHIN and ACE/EPAM will be presented. |
|15:20||3D Modelling of Heavy Ion Solar Energetic Particle Propagation||Dalla, S et al.||Oral|
| ||Silvia Dalla, Mike S. Marsh, Markus Battarbee and Timo Laitinen|
| ||University of Central Lancashire, UK; Met Office, UK|
| ||Heavy ion Solar Energetic Particles (SEPs) are less numerous than protons but, characterised by a range of mass to charge ratios, they provide an important probe into the m/q-dependent acceleration and transport processes which determine SEP fluences at near-Earth locations. Traditionally, the propagation of SEPs through interplanetary space is modelled using a single spatial variable, the distance travelled along a magnetic field line. In this work we model the trajectories of SEP Fe and O ions from the Sun to 1 AU locations by means of a full orbit test particle model. Fe ions of different charge states are studied. We show that heavy ion propagation takes place in 3D: particles experience very significant transport across the magnetic field due to guiding centre drift, associated with the curvature and gradient of the Parker spiral magnetic field. We derive intensity profiles that would be measured by a 1 AU observer and show that our model reproduces two key features of SEP heavy ion data: the decrease over time in the Fe/O ratio and the increase with energy of the event-averaged ionic charge state of Fe.|
|15:40||Estimating the risk of SEPE: a service dedicated to spacecraft operations. Feedbacks from ATV and GAIA missions||Yaya, P et al.||Oral|
| ||Philippe Yaya, Louis Hecker|
| ||Hvar Observatory, Faculty of Geodesy, Kačićeva 26, HR-10000 Zagreb, Croatia; Institute for Experimental and Applied Physics, Christian-Albrechts-University Kiel, Germany; Institute of Physics, University of Graz, Universitätsplatz 5, A-8010 Graz, Austria|
| ||CLS, a subsidiary of the French Space Agency, has been providing a service dedicated to SEPE forecast since 2007. It consists in estimating the level of risk of a proton event at a given flux depending on the sensitivity of the mission instruments. Every day of the mission, CLS operators perform a detection and analysis of various indicators and precursors of strong solar flares. This analysis is based on a statistical method with numerical criteria which have been tested over more than a solar cycle and have shown encouraging statistics in terms of SEPE detection. This activity has also been extended to specific launchers. A feedback from the five ATV missions as well as the Gaia mission is given.|
|17:00||NGRM Next Generation Radiation Monitor new standard instrument for ESA||Hajdas, W et al.||Oral|
| ||Wojtek Hajdas, Radoslaw Marcinkowski, Hualin Xiao, Alankrita Isha Mrigakshi|
| ||Paul Scherrer Institute (PSI), Villigen, Switzerland|
| ||European Space Agency ESA together with RUAG AG and PSI started a successful collaboration
for development and implementation of the Standard Radiation Environment Monitor SREM for its satellites.
Out of ten produced and qualified SREM instruments six are still flying. Such the success triggered
development of a new, more advanced instrument called the Next Generation Radiation Monitor NGRM.
The previous collaboration was extended including companies and institutes responsible for design
of electronics, development of the ASIC and modeling of the satellite for spectra unfolding.
Currently the project completed its tests with the Engineering Model EM and the first Flight Models
FMs were produced and initially characterized. NGRM is a compact, low mass and low power radiation
monitor for space. It allows for measurements of electrons and protons in the energy range
characteristics for radiation environments around the Earth. The concept was optimized using
particle physics detection techniques including dedicated Si-sensors and new low power and
radiation hard ASICs (IDEAS). The main instrument parameters are: mass – 1 kg, power – 1 W,
volume 1 L; proton energy range: 2 MeV – 200 MeV; electron energy range: 100 keV – 7 MeV;
spectral resolution: at least 8 bins equally spaced on the log-scale; maximum counting rates:
109 /cm2/s for electrons and 108 /cm2/s for protons. PSI delivered and elaborated the instrument
concept with respect to its detection system. It comprised design and testing of Si-sensors for
NGRM subsystems including novel circular microstrip for electrons and standard telescope for
protons and heavy ion measurements. Our team also developed the mass model and response theoretical
response functions based on Monte Carlo simulations with GEANT4. This package is used for validation
of the concept validation and analysis of the data from calibration runs at PSI particle facilities.
All tasks started with bread-board manufacturing and concept validation. Currently the first
calibrations and verifications of the engineering model are completed and PSI beam facilities
await arrival of the flight models. We will discuss NGRM features and performance of its detector
system. Particle response matrix, proton-electron separation and spectral unfolding will be presented.
NGRM calibration and verification data will be compared with the Monte Carlo modeling. We will also
shortly address the NGRM upgrade with additional systems of environmental sensors.|
|17:25||Modelling the SEP environment using the SAPPHIRE model||Jiggens, P et al.||Oral|
| ||Piers Jiggens, Daniel Heynderickx, Athina Varotsou, Pete Truscott, Fan Lei, Ingmar Sandberg, Rami Vainio, Osku Raukunen|
| ||ESA/ESTEC (NL); DH Consultancy (BE); TRAD Tests and Radiations (FR); Kallisto Consultancy (UK); RadMod Research (UK); Institute for Accelerating Systems and Applications (GR); University of Turku (FI)|
| ||Models of SEP environment are important for specification of the environment which impacts spacecraft through ionizing and non-ionizing dose effect and can also endanger humans in space. Accuracy in specifying these environments is important for mission planning and can help to reduce margins and unnecessary weight applied to shield components and people while limiting risk to mission success.
Historically there have been several de-facto standard models of the SEP environment employed by different agencies at different times including the King (SOLPRO), JPL, ESP (PSYCHIC) and MSU models. Herein a new model is proposed to be considered as a standard model based on the most extensive homogenous SEP data set, carefully processed and rigorously cleaned and cross-calibrated to take advantage of the best aspects of SEP monitor and science-level data. The instrument and consolidated data sets are freely available to the public via ftp.
The SAPPHIRE model provides estimates of SEP mission cumulative fluence, worst-case event fluence and peak fluxes for proton spectra, helium spectra and heavy ion spectra also included as a function of Linear Energy Transfer (LET). A method to translate the probabilistic worst-case event outputs into mean occurrence rate of events is also presented. The comprehensive model provides a consistent, probabilistic approach to analyses of total ionizing dose (TID), non-ionizing dose (NID) and single event effects (SEEs) over a range of timescales.
Models for protons and helium are developed using identical methodologies and based on the helium outputs the heavy ion outputs are derived. This requires the use of abundances ratios which have been derived from data from the SIS instrument on-board ACE compared to the cross-calibrated helium data.
Some results are presented with comparisons to outputs from older models. This work was carried out as part of ESA’s Energetic Solar Heavy Ion Environment Models (ESHIEM) activity supported by ESA's Technology Research Programme (TRP) - ESA Contract 4000107025/12/NL/GLC. The models are being implemented on ESA’s SEPEM system for derivation of SEP environments and ESA’s SPENVIS system for space environment and effects estimations/specifications. Other important work carried out in this activity and related activities - including error estimation, geomagnetic shielding impacts incorporated into SEP models and heliospheric variability of SEP fluxes – are not presented herein.|
|17:50||New approaches in SEP description and modelling||Sandberg, I et al.||Oral|
| ||Ingmar Sandberg, Sigiava A. Giamini, Constantinos Papadimitriou, Ioannis A. Daglis[1,2] and P. Jiggens|
| ||Institute of Accelerating Systems and Applications, Athens, Greece; Department of Physics, National and Kapodistrian University of Athens, Athens, Greece.; European Research and Technology Centre, European Space Agency, Noordwijk, The Netherlands.|
| ||Novel approaches in the analysis and description of Solar Energetic Proton (SEP) measurements and Solar Proton Events (SPE) are presented. We use the SEPEM 2.0 database (cross-calibrated GOES measurements) and introduce proton flux moments of different order to provide a coherent picture of SEP data and reveal interdependencies between SPE characteristics. In addition, we demonstrate that the occurrence frequency distribution of SPE peak flux follows a power law distribution – exhibiting characteristics of Self Organising Criticality– and present a first-principle SPE model. Last, based on the above findings we propose a scheme for the effective coupling of Solar Proton and Trapped Radiation environment models.
Acknowledgements: This work is performed in the framework of the Hellenic Evolution of Radiation data processing and Modeling of the Environment in Space (HERMES) project, implemented by IASA under ESA contract no. 4000112863/14/NL/HB.
|18:10||Extreme Atmospheric Radiation Environments and Effects||Dyer, C et al.||Oral|
| ||Clive Dyer[1,2], Alex Hands, Keith Ryden, Fan Lei|
| ||CSDRadConsultancy; University of Surrey Space Centre; RADMOD Research|
| ||Since the deployment of ground level ionization chambers in 1942 followed by neutron monitors in 1948, some 71 ground level enhancements have been observed. Of these some 14 have exceeded 100% at ground level. Calculations using data from ground and space monitors together with radiation transport codes in the MAIRE system (Models for Atmospheric Ionizing Radiation Effects) show these to be of significance for air travel;i.e. > 0.5 mSv on certain flight routes, together with high rates of single event effects in avionics. The most severe of these events on 23 February 1956 can be used as a worst case on a timescale of some 70 years. This can provide challenging levels of radiation for air flight, giving annual recommended limits to air crew and rates of single event effects that could challenge mitigation techniques. Further data are available from cosmogenic nuclide studies, such as C14 and Be10. Events of AD774 and AD993 are currently believed to be of solar origin and could give levels some one to two orders of magnitude greater than February 1956 event. Such levels become hazardous for safety critical ground level systems and would make avoidance procedures essential for air flights both from the viewpoint of dose to crew and passengers and the viewpoint of avionics safety. At present there are no direct data on radiation levels from the Carrington Event and it is important to fill in the size probability distribution between 70 years and 1000 years. Design standards for avionics must take account of these levels and be harmonised with avoidance levels to limit dose to crew and passengers. Appropriate avoidance strategies need to be be developed bearing in mind the very rapid onset times for most such events observed in recent history.|
PostersMonday November 14, 16:00 - 17:00, Poster Area
|1||Database of Ground Level Enhancements (GLE) of High Energy Solar Proton Events||Poluianov, S et al.||e-Poster|
| ||Ilya Usoskin[1,2], Stepan Poluianov, Askar Ibragimov|
| ||ReSoLVE, University of Oulu, Finland; Sodankylä Geophysical Observatory, University of Oulu, Finland; University of Helsinki, Finland|
| ||We present an international ground level enhancemen/event (GLE) database based on observations of the world-wide network of neutron monitors. The database is hosted by the University of Oulu, it is an inheritance of similar databases developed in USA and Australia. The address of the database is gle.oulu.fi.|
|2||SOHO/ERNE measurements of solar heavy ions during solar cycles 23 and 24||Vainio, R et al.||e-Poster|
| ||Osku Raukunen, Eino Valtonen, Rami Vainio|
| ||Department of Physics and Astronomy, University of Turku, Finland|
| ||Solar cycle 24 has shown considerably lower overall solar activity level than the previous cycle 23. This has also had an effect on the solar energetic particle (SEP) events; for example, the number of ground level enhancements (GLEs) caused by SEPs has decreased from 16 in cycle 23 to only one in cycle 24 as of this writing. We have analyzed the SOHO/ERNE heavy ion data (from carbon to iron) from the beginning of solar cycle 23 until the end of May 2016, i.e., long into the declining phase of cycle 24. We have studied the daily intensities and abundance ratios of heavy ions as well as the heavy ion composition during SEP events and compared the cycles in those respects. Our results reflect the decreased solar activity and indicate lower efficiency of heavy ion acceleration processes for SEP events in cycle 24.|
|3||Foretelling Flares and Solar Energetic Particle Events: the FORSPEF tool||Anastasiadis, A et al.||e-Poster|
| ||A. Anastasiadis, A. Papaioannou, I. Sandberg, M. K. Georgoulis, K. Tziotziou, D. Paronis, P. Jiggens, A. Hilgers|
| ||IAASARS, National Observatory of Athens, Greece; RCAAM, Academy of Athens, Greece; ESA/ESTEC, The Netherlands |
| ||A novel integrated prediction system, for both solar flares (SFs) and solar energetic particle (SEP) events is being presented. The Forecasting Solar Particle Events and Flares (FORSPEF) provides forecasting of solar eruptive events, such as SFs with a projection to coronal mass ejections (CMEs) (occurrence and velocity) and the likelihood of occurrence of a SEP event. In addition, FORSPEF, also provides nowcasting of SEP events based on actual SF and CME near real-time data, as well as the complete SEP profile (peak flux, fluence, rise time, duration) per parent solar event. The prediction of SFs relies on a morphological method: the effective connected magnetic field strength (Beff); it is based on an assessment of potentially flaring active-region (AR) magnetic configurations and it utilizes sophisticated analysis of a large number of AR magnetograms. For the prediction of SEP events new methods have been developed for both the likelihood of SEP occurrence and the expected SEP characteristics. In particular, using the location of the flare (longitude) and the flare size (maximum soft X-ray intensity), a reductive statistical method has been implemented. Moreover, employing CME parameters (velocity and width), proper functions per width (i.e. halo, partial halo, non-halo) and integral energy (E>30, 60, 100 MeV) have been identified. In our technique warnings are issued for all > C1.0 soft X-ray flares. The prediction time in the forecasting scheme extends to 24 hours with a refresh rate of 3 hours while the respective prediction time for the nowcasting scheme depends on the availability of the near real-time data and falls between 15-20 minutes for solar flares and 6 hours for CMEs. We present the modules of the FORSPEF system, their interconnection and the operational set up. The dual approach in the development of FORPSEF (i.e. forecasting and nowcasting scheme) permits the refinement of predictions upon the availability of new data that characterize changes on the Sun and the interplanetary space, while the combined usage of SF and SEP forecasting methods upgrades FORSPEF to an integrated forecasting solution.
This work has been funded through the “FORSPEF: FORecasting Solar Particle Events and Flares”, ESA Contract No. 4000109641/13/NL/AK
|4||Correlation between Spacecraft Anomalies and Solar Energetic Proton||Lee, H et al.||p-Poster|
| ||Harim Lee, KiChang Yoon, JangSuk Choi, Dong-Kyu Kim, Yeongoh Choi|
| ||RRA Korean Space Weather Center, Jeju, Korea|
| ||It is well known that Solar Energetic Proton (SEP) can cause significant effects on electric devices in satellite such as displacement damage and single event effect. It can be dangerous to flight crew/passenger flying high altitude with polar route, and therefore, it is essential that it should be predicted in advance to mitigate radiation exposure risk. However, SEP has been hard to predict, because it is not well-connected solar activities such as solar flare, coronal mass ejection (CME). In this study, we investigate spacecraft anomalies from 1985 to 2014. We use the anomaly data and classify these data according to types of anomaly and spacecraft orbit. We examine the association between these anomaly data and proton flux data from GOES as well as their occurrence rates. We find that the proton peak flux and anomalies are correlated. This fact implies that energetic proton particles directly penetrate the spacecraft and shortly induce anomalies. It is expected that the Korean Space Weather Center suggests a threshold value to prevent spacecraft anomalies from solar energetic proton.|
|5||Characterization of solar energetic H and He spectra measured by the Energetic Particle Telescope (EPT) on-board PROBA-V during the January 2014 SEP event||Benck, S et al.||p-Poster|
| ||Sylvie Benck, Stanislav Borisov, Mathias Cyamukungu, Hugh Evans, Petteri Nieminen|
| ||Center for Space Radiations, Earth and Life Institute, Université catholique de Louvain, (UCL/CSR); European Space Agency (ESA) |
| ||On January 6, 2014 at 09:15 UTC a Solar Energetic Particle (SEP) event started that led to a 1030 1/(cm^2 s sr) peak flux of E>10 MeV protons on January 9, 2014 at 03:40 UTC (measured by GOES at geosynchronous orbit); a proton peak flux exceeded only by about 15% of all SEP events. Such high flux events contribute the most to SEP event-induced radiation effects in space equipment, while being easy to characterize based on data acquired by medium geometrical factor spectrometers, such as the Energetic Particle Telescope (EPT). This latter was designed to provide uncontaminated fluxes of electrons (0.5–20 MeV), protons (9.5–300 MeV) and α-particles (38–1200 MeV). It was accommodated on the PROBA-V satellite launched on May 7th, 2013 onto a Low Earth Orbit of 820 km altitude and 98.7° inclination.
Alpha-particles contribution to Total Non-Ionizing Dose (TNID) in Silicon has been shown to be by a factor 2-10 higher than that of protons in the 0.001 – 1000 MeV/n energy range. Considering that SEP events constitute representative space environments where He and H could generate TNID-related effects, a data analysis was performed to identify periods of high He flux as compared to H, as well as conditions under which both ions must be accounted for during radiation effect analyses. From that starting point, a full characterization of the H and He fluxes measured during the January 2014 SEP event was undertaken, including the determination of:
- the minimum L-value reached by solar H and He ions for a given rigidity;
- the shape of solar H and He energy spectra;
- the H/He fluence ratio;
- H and He pitch angle distributions;
- the relative contributions of H and He to Total Ionizing Dose (TID) and TNID;
- the relative contribution of H and He to Single Event Effects (SEE) by direct ionizations.
Based on the study results, the presentation at ESWW13 will provide tentative replies to the questions: (i) Should He flux be included in SW alert information? (ii) Should He be accounted for in evaluation of cumulative radiation effects? (iii) For a given device, what should be its (direct ionization) SEE cross-section and threshold LET in order to be affected by SEP?
|6||ZENITH: A Rapid-release balloon-mounted radiation probe to validate Space Weather warnings for Aircraft||Dyer, A et al.||p-Poster|
| ||Alexander Dyer, Keith Ryden, Catherine Burnett, Mark Gibbs|
| ||University of Surrey, University of Surrey, Met Office, Met Office|
| ||During highly energetic solar particle events atmospheric neutron fluxes can increase by orders of magnitude over a matter of minutes which can pose a threat to aircraft avionics (via single event effects) and can also increase the radiation doses experienced by passengers and crew. Some airlines change aircraft routing in order to mitigate such effects based on space weather alerts from NOAA SWPC. When alerts are received it would be beneficial to probe high altitude regions to measure the neutron fluxes encountered and correlate these with risks to electronics. Thus it is important to measure changes in the neutron environment when such alerts are given out. Given that few suitable monitors are flown routinely on aircraft, this paper describes a new initiative to provide a rapid-reaction measurement system using meteorological balloons. The system known as Zenith aims to record the atmospheric radiation environment as the weather balloon ascends to an altitude of ~ 35 km. Zenith is capable of recording events which deposit 100 keV – 100 MeV in a PIN diode. These events are placed in logarithmic bins over the 100 keV – 100 MeV energy range. After every minute observation window the counts in the bins are stored on the microSD card and transferred over the SPI interface to either the radiosonde for transmission back to the ground station or to LabView. The balloon uses a Vaisala RS92 radiosonde which is used to transmit the data to the Met Office’s 24 hour manned weather station. Zenith has also been designed as a standalone instrument, recording all data to a microSD card as well as passing the data through the SPI peripheral to a laptop running LabView, offering a live monitoring system. The paper will describe the overall Zenith development and status and outline results of early flight trials on aircraft and balloons. |
|7||Error Propagation for Proton and Heavy Ion Statistical Modelling in the SEPEM System||Truscott, P et al.||p-Poster|
| ||Pete Truscott, Fan Lei, Daniel Heynderickx, Athina Varotsou, Ingmar Sandberg, Piers Jiggens, Hugh Evans|
| ||Kallisto Consultancy, UK; RadMod Research, UK; DH Consultancy, Belgium; TRAD, France; IASA, Greece; ESA/ESTEC, The Netherlands|
| ||The use of solar particle event (SEP) statistical models has become a standard technique for estimating the potential severity of the SEP environment for a spacecraft as a function of mission epoch, duration and confidence level (CL). However the effects of uncertainties within the modelling process and input data are rarely addressed. Indeed, the CL, which reflects the potential variability of the environment due to the statistical nature of the SEPs, is often misunderstood by satellite engineers as quantifying modelling errors as well. The key sources of uncertainty include:
• Accuracy of the instrument energy and efficiency calibration.
• Count statistics in the instrument data.
• Statistical uncertainties in the event list, i.e. how accurately the list of events, which us used to build the model, represents the true statistics of the SEPs.
• Artefacts introduced as a result of data cleaning and background subtraction.
• Where heavy ion (HI) abundance ratios are used to convert proton or He statistical models results to estimate HI mission or event fluences and peak fluxes, uncertainties in the abundance ratios arise again from calibration, cleaning, background subtraction and the limited event statistics in the HI data.
• For spacecraft operating within Earth’s magnetosphere, the errors in the modelling of the geomagnetic shielding for particles in orbital positions.
The Solar Energetic Particle Environment Models (SEPEM) system has been developed by ESA to provide a comprehensive environment to build solar proton models using reference datasets, and execute these models to predict the particle environment, shielding and effects quantities for spacecraft. ESA’s ESHIEM (Energetic Solar Heavy Ion Environment Models) project has been extending this capability in order to treat all solar ion species, to calculate geomagnetic shielding effects, and the treat the propagation of the principal uncertainties discussed above. This paper describes the methods to incorporate error estimates into the statistical models, and propagate these into the results, including geomagnetic and physical shielding model uncertainties. The relative importance of these different sources to the overall error in the estimate of particle flux, fluence, ionising or non-ionising dose, etc. is discussed.
|8||SEP acceleration and the choice of the simulation methods to model them||Lapenta, G et al.||p-Poster|
| ||Giovanni Lapenta, Elisabetta Boella, Diego Gonzalez|
| ||KU Leuven|
| ||To model particle acceleration in space weather events (as in any other natural and laboratory process) requires the ability to understand and describe correctly the microphysics that enables the transfer of energy to particles. Particle acceleration can only be done by electric fields and often these are at scales so small that kinetic processes need to be described correctly. At shocks, for example, kinetic instabilities due to peculiar features of the phase space distribution of electrons and ion cause significant electron and ion acceleration.
Modelling these processes requires the solution of the Boltzmann equation via direct discretization on a phase space grid or via particle in cell methods. Whichever is used, energy conservation is critical. Most methods do not conserve energy exactly, meaning by this to round off precision of the computational processor (be it a GPU, a CPU or a MIC). We present a new approach that is absolutely exact, conserves energy to machine precision. We briefly mention the mathematical proof but rely on examples to prove in practice the fidelity of energy conservation.
Via the new approach we demonstrate a unexpected finding: an exactly energy conserving scheme provides much more efficient energization of the particle than non exact schemes even when those inexact schemes give an excellent overall energy conservation. The power law obtained by acceleration by streaming instabilities (such as those expected to operate at shocks) is significantly underestimated by even exceedingly accurate time steps when inexact energy conserving methods are used. Exact energy conservation is critical because small fractions of particles are accelerated to high energies and even when overall energy conservation is good those few highly accelerated particles will be treated badly. The new approach completely eliminates this shortcoming. An this is obtained with a smaller computational cost. There is no reason to continue to use older inexact schemes. |
|9||The updated SEPEM/SOLPENCO2 tool: application to an interplanetary mission.||Aran, A et al.||p-Poster|
| ||Angels Aran, Daniel Pacheco, Piers Jiggens, Daniel Heynderickx, N. Agueda, Blai Sanahuja|
| ||Dep. de Física Quàntica i Astrofísica i Institut de Ciències del Cosmos, Universitat de Barcelona, Spain; European Space Research and Technology Centre, ESA, The Netherlands; DH Consultancy, Leuven, Belgium|
| ||The SOLPENCO2 tool was developed during the ESA’s solar energetic particle (SEP) Environment Modelling (SEPEM) project (http://dev.sepem.oma.be). This tool provides the SEPEM statistical analysis tools for interplanetary missions with heliocentric radial distance scaling parameters. In the frame of the recent SOL2UP project, funded by ESA, we have upgraded the SOLPENCO2 tool:  We have enlarged the number of events in the SEPEM radial dependent event list (SREL) by analysing the SEP events occurring during the period from 2007 to March 2013.  We have increased the number of reference cases modelled with the SOLPENCO2 tool.  We have studied the variation of the downstream fluence of SEP events with respect to the position of the observer (both radial distance and longitude) with respect to the site of the solar eruption originating the SEP event, in order to revisit the assumption made in SOLPENCO2.  We have classified the 267 SEP events in SREL into ten categories and computed the peak intensity and event fluence values for these events at seven heliocentric distances, from 0.2 to 1.6 AU. We present the latest results of the SOL2UP project and apply the new event list to the SEPEM environment specification model for interplanetary spacecraft to a possible orbit for the entire Solar Orbiter mission.|
|10||Solar Energetic Particle propagation within and near a heliospheric current sheet||Battarbee, M et al.||p-Poster|
| ||Markus Battarbee, Silvia Dalla, Mike Marsh|
| ||University of Central Lancashire, UK; Met Office, UK|
| ||The propagation of Solar Energetic Particles (SEPs) is a key component of predicting space weather and energetic particle fluxes at the Earth. Especially important is the understanding of the connection between observations at 1 AU and coronal acceleration regions. Drifts and scattering within the Interplanetary Magnetic Field (IMF) have a significant effect on the relationship between in-situ observations and the location of the parent active region at the Sun.
The dipole magnetic field of the Sun is stretched due to the solar wind, forming a Heliospheric Current Sheet (HCS) between two hemispheres of opposite polarities. It is well known from galactic cosmic ray studies, that the HCS has a significant effect on particle propagation.
We present 3-D full-orbit test particle simulations of solar energetic protons, launched from the solar corona and propagating within a Parker spiral IMF, modified to account for a flat current sheet. We assess asymmetry of particle drifts due to solar magnetic field orientation and the magnitudes of current sheet drifts. We quantify the effects of current sheet thickness on propagation of SEP protons with energies ranging from 10 to 400 MeV. We discuss the implications of current sheet waviness and the effects on space weather prediction.|
|11||Acceleration, Transport, Forecasting and Impact of solar energetic particles in the framework of the ‘HESPERIA’ HORIZON 2020 project||Malandraki, O et al.||p-Poster|
| ||O. E. Malandraki, K. Tsinganos[1*], K.-L. Klein, R. Vainio, N. Agueda, M. Nunez, B. Heber, R. Buetikofer, C. Sarlanis, N. Crosby, G. Share, R. Murphy, A. J. Tylka, V. Bindi, J. Rodriguez, A. Afanasiev, A. Aran, M. Battarbee, E. Christia, M. Dierckxsens, J. Dimitroulakos, D. Galsdorf, C. Hamadache, K. Herbst, J. Kiener, P. Kuehl, J. Labrenz, J. Marquardt, N. Milas, A. Papaioannou, E. G. Pavlos, P. Reyes, B. Sanahuja, D. Sfakianakis, G. Souvazoglou, C. Steigies, V. Tatischeff, G. Tsiropoula, K. Tziotziou, E. Valtonen, N. Vilmer, P. Zucca|
| ||IAASARS, National Observatory of Athens, GR-15236 Penteli, Greece; [1*]National Observatory of Athens, Athens Greece; Observatoire de Paris, Meudon, France; University of Turku, Finland; University of Barcelona, Spain; University of Malaga, Spain; Christian-Albrechts-Universitaet zu Kiel, Germany; University of Bern, Switzerland; ISNet Co, Athens, Greece; Royal Belgian Institute for Space Aeronomy, Brussels, Belgium; Naval Research Laboratory, Washington DC, USA; Emeritus, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA; University of Hawai at Manoa, Honolulu, USA; NOAA, USA|
| ||High-energy solar energetic particles (SEPs) emitted from the Sun are a major space weather hazard motivating the development of predictive capabilities. In this work, the current state of knowledge on the origin and forecasting of SEP events will be reviewed. Subsequently, we will present the ongoing EU HORIZON2020 HESPERIA (High Energy Solar Particle Events foRecastIng and Analysis) project, its structure, its main scientific objectives and forecasting operational tools, as well as the added value to SEP research both from the observational as well as the SEP modelling perspective. The project addresses through multi-frequency observations and simulations the chain of processes from particle acceleration in the corona, particle transport in the magnetically complex corona and interplanetary space to the detection near 1 AU. Furthermore, publicly available software to invert neutron monitor observations of relativistic SEPs to physical parameters that can be compared with space-borne measurements at lower energies will be provided for the first time by HESPERIA. In order to achieve these goals, HESPERIA is exploiting already available large datasets stored in databases such as the neutron monitor database (NMDB) and SEPServer that were developed under EU FP7 projects from 2008 to 2013. First forecasting results of the two novel SEP operational forecasting tools published via the consortium server of ‘HESPERIA’ will be presented, as well as some scientific key results on the acceleration, transport and impact on Earth of high-energy particles. Acknowledgement: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 637324.|
|12||PAMELA's Measurements of Solar Energetic Particles||Bruno, A et al.||p-Poster|
| ||Alessandro Bruno, on behalf of the PAMELA collaboration|
| ||INFN and University of Bari, Italy|
| ||The PAMELA satellite experiment, in low Earth orbit since June 2006, is providing comprehensive observations of the Solar Energetic Particle (SEP) events between solar cycles 23 and 24. Its unique capabilities include the possibility of accurately measuring the SEP energetic spectra in a large interval (>80 MeV), encompassing the low energy data by other space-based instruments and the Ground Level Enhancement (GLE) data by the worldwide network of neutron monitors. Furthermore, PAMELA is able to measure the flux angular distribution and thus investigate possible anisotropies. The analysis is supported by back-tracing techniques based on a realistic modeling of the terrestrial magnetosphere, which enables to reconstruct the asymptotic pitch-angle distribution of SEPs with respect to the local interplanetary magnetic field. PAMELA results significantly enhance the characterization of SEP fluxes in the near-Earth space, constraining the scenarios for particle acceleration and transport mechanisms.|
|13||False Alarms in the Forecasting of Solar Energetic Particle Events||Bill, S et al.||p-Poster|
| ||Bill Swalwell, Silvia Dalla, Robert Walsh|
| ||Jeremiah Horrocks Institute, University of Central Lancashire, Preston, PR1 2HE |
| ||Solar flares which exhibit high levels of emission in soft X-rays and coronal mass ejections
(CMEs) with high speed have long been associated with the production of Solar Energetic Particles
(SEPs) within Space Weather forecasting systems. However it is not the case that SEPs are
detected at Earth following all such events.
Here we present a statistical analysis of X class flares and CMEs with a reported speed greater than
1,500 km/s ("fast CMEs") which occurred from a site on the solar surface west of E20. Such events
are generally considered to have a high likelihood of producing SEPs. By analysing proton data from
the GOES EPS instruments between 1976 and 2013, we determine which solar events resulted
in SEPs being detected at Earth and which did not - the "false alarms".
We find that, in the time range 1996 to 2013, forecasting an SEP event at Earth based on the detection
of a fast CME would have produced 54 positive forecasts, of which 16 were false alarms (30%). In the
same time range, an algorithm based on the detection of an X class flare would have generated 73
forecasts, of which 36 were false alarms (49%). Requiring both an X class flare and a fast CME would
have given 25 positive forecasts, of which 3 were false alarms (12%). We present an analysis of the
properties of the false alarm events including their location on the solar disk and their timing within
the solar cycle.|
|14||Microwave observations for forecasting energetic particles from the Sun ||Zucca, P et al.||p-Poster|
| ||Pietro Zucca, K.-Ludwig Klein, Marlon Núñez, Rositsa Miteva|
| ||Observatoire de Paris, LESIA - CNRS UMR 8109, 92195 Meudon; Departamento de Lenguajes y Ciencias de la Computación, Universidad de Málaga, Málaga, Spain; Bulgarian Academy of Sciences (SRTI-BAS), Academia georgy Bonchev Str. bl.1. , 1113 Sofia|
| ||Predicting when solar energetic particles (SEPs) will hit Earth, and in what concentrations and energies, is important to mitigating space weather hazards ranging from communications outages to high radiation levels on polar aircraft routes. The university of Malaga developed a forecast tool for SEPs called UMASEP. This tool uses time derivatives of the proton profile observed in space and of the soft X-ray flux to predict if a SEP event is to occur, and how it will evolve. In the frame of the HESPERIA project, funded by the Horizon 2020 programme of the European Union, we conduct an extensive study on the use of microwave observations to replace or accompany the soft X-ray first derivative in the SEP forecast. In addition, we are conducting a study to predict the hardness of the energy spectrum of the incoming protons at Earth employing microwave spectral properties, using a method devised by I. Chertok and collaborators. This contribution is to present first results on the two subjects, using a sample microwave observational period of 3 months and a sample of 15 test events: (1) We constructed an uninterrupted time profile over three months using the four RSTN stations of the US Air Force, and fed this profile into the UMASEP scheme instead of the soft X-ray observations. (2) We tested the capability of the microwave spectral characteristics on the incoming proton energy forecast by comparing predicted and observed proton spectra in interplanetary space for 15 events between 2003 and 2006. These tests are preliminary, and are to be extended to a large data set in the coming months.
Acknowledgement: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 637324.
|15||Quantitative comparison between KREAM (Korean Radiation Exposure Assessment Model for aviation route dose) and NAIRAS||Hwang, J et al.||p-Poster|
| ||Gyeongbok Jo[1,2], Junga Hwang[2,3], Kyunghwan Dokgo, Eunjin Choi, Sung-Jun Noh[2,6], and W. Kent Tobiska|
| ||Chungnam National University (CNU), South Korea; Solar and Space Weather group, Korea Astronomy and Space Science Institute (KASI), South Korea; Department of Astronomy and Space Science, University of Science and Technology (UST), South Korea; Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), South Korea; Goddard Space Flight Center/NASA, USA; Chungbuk National University (CBNU), South Korea; Space Environment Technologies, USA|
| ||Estimation of galactic cosmic ray (GCR) and solar energetic proton (SEP) transport in the Earth’s atmosphere is essential to evaluate an aviation route dose. These energetic particles affect to the aviation doses by itself and by generating secondary particles’ cascade in the Earth’s atmosphere. We develop a particle transport model, Korean Radiation Exposure Assessment Model for aviation route dose (KREAM). Particle transports and secondary generation are calculated using GEANT4 code. Integrating these simulation results, we make a global response matrix for incident energetic protons making possible to predict real-time dose depending on the various space weather conditions. With a NRLMSIS-00 atmospheric model, our model, KREAM, generates equivalent dose map depending on latitude, longitude and altitude. Comparison between KREAM, CARI-6 and NAIRAS for Halloween event (28, Oct, 2003) shows good agreements between those. In this paper, we present the results of quantitative comparison between NAIRAS and KREAM based on global dose and route dose. And we also carry out the validation by using ground data from Neutron Monitor observation and in-situ dose data from Liulin-6K onboard commercial flights of Korean Air and Czech University of Life Sciences Prague (CULS) covering one solar cycle||