Astrophysics and Space Science Library 444 Olga E. Malandraki Norma B. Crosby Editors Solar Particle Radiation Storms Forecasting and Analysis The HESPERIA HORIZON 2020 Project and Beyond Solar Particle Radiation Storms Forecasting and Analysis Astrophysics and Space Science Library EDITORIAL BOARD Chairman W. B. BURTON, National Radio Astronomy Observatory, Charlottesville, Virginia, U.S.A. ([email protected]); University of Leiden, The Netherlands ([email protected]) F. BERTOLA, University of Padua, Italy C. J. CESARSKY, Commission for Atomic Energy, Saclay, France P. EHRENFREUND, Leiden University, The Netherlands O. ENGVOLD, University of Oslo, Norway E. P. J. VAN DEN HEUVEL, University of Amsterdam, The Netherlands V. M. KASPI, McGill University, Montreal, Canada J. M. E. KUIJPERS, University of Nijmegen, The Netherlands H. VAN DER LAAN, University of Utrecht, The Netherlands P. G. MURDIN, Institute of Astronomy, Cambridge, UK B. V. SO M OV, Astronomical Institute, Moscow State University, Russia R. A. SUNYAEV, Max Planck Institute for Astrophysics, Garching, Germany More information about this series at http://www.springer.com/series/5664 Olga E. Malandraki • Norma B. Crosby Editors Solar Particle Radiation Storms Forecasting and Analysis The HESPERIA HORIZON 2020 Project and Beyond Editors Olga E. Malandraki Norma B. Crosby National Observatory of Athens Space Physics Division - Space Weather IAASARS Royal Belgian Institute for Space Aeronomy Athens, Greece Brussels, Belgium ISSN 0067-0057 ISSN 2214-7985 (electronic) Astrophysics and Space Science Library ISBN 978-3-319-60050-5 ISBN 978-3-319-60051-2 (eBook) DOI 10.1007/978-3-319-60051-2 Library of Congress Control Number: 2017957900 © The Editor(s) (if applicable) and The Author(s) 2018. This book is an open access publication. Open Access This book is licensed under the terms of the Creative Commons Attribution 4.0 Inter- national License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made. The images or other third party material in this book are included in the book’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the book’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Cover illustration: Space Situational Awareness: Space Weather. Credit: ESA-P. Carril Printed on acid-free paper This Springer imprint is published by Springer Nature The registered company is Springer International Publishing AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland Preface Ranging in energy from tens of keV to a few GeV solar energetic particles (SEPs) are an important contributor to the characterization of the space environment. Emitted from the Sun they are associated with solar flares and shock waves driven by coronal mass ejections (CMEs). SEP radiation storms may last from a period of hours to days or even weeks and have a large range of energy spectrum profiles. These events pose a threat to modern technology relying on spacecraft and humans in space as they are a serious radiation hazard. Though our understanding of the underlying physics behind the generation mechanism of SEP events and their propagation from the Sun to Earth has improved during the last decades, to be able to successfully predict a SEP event is still not a straightforward process. The motivation behind the 2-year HESPERIA (High Energy Solar Particle Events forecasting and Analysis) project of the EU HORIZON 2020 programme, success- fully completed in April 2017, was indeed to further our scientific understanding and prediction capability of high-energy SEP events by building new forecasting tools while exploiting novel as well as already existing datasets. HESPERIA, led by the National Observatory of Athens, with Project Coordinator Dr. Olga E. Malandraki, was a consortium of nine European teams that also collaborated during the project with a number of institutes and individuals from the international community. The complementary expertise of the teams made it possible to achieve the main objectives of the HESPERIA project: • To develop two novel real-time SEP forecasting systems based upon proven concepts. • To develop SEP forecasting tools searching for electromagnetic proxies of the gamma-ray emission in order to predict large SEP events. • To perform systematic exploitation of novel high-energy gamma-ray observa- tions of the FERMI mission together with in situ SEP measurements near 1 AU. • To provide for the first time 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. v vi Preface • To perform examination of currently unexploited tools (e.g. radio emission). • To design recommendations for future SEP forecasting systems. This book reviews our current understanding of SEP physics and presents the results of the HESPERIA project. In Chap. 1 the book provides a historical overview on how SEPs were discovered back in the 1940s and how our understanding has increased and evolved since then. Current state of the art based on the unique measurements analysed in the three-dimensional heliosphere and the key SEP questions that remain to be answered in view of the future missions Solar Orbiter and Parker Solar Probe that will explore the solar corona and inner heliosphere are also presented. This is followed by an introduction to why SEPs are studied in the first place describing the risks that SEP events pose on technology and human health. Chapters 2 through 6 serve as background material covering solar activity related to SEP events such as solar flares and coronal mass ejections, particle acceleration mechanisms, and transport of particles through the interplanetary medium, Earth’s magnetosphere and atmosphere. Furthermore, ground-based neutron monitors are described. The last four chapters of the book are dedicated to and present the main results of the HESPERIA project. This includes the two real-time HESPERIA SEP forecasting tools that were developed, relativistic SEP related gamma-ray and radio data comparison studies, modelling of SEP events associated with gamma-rays and the inversion methodology for neutron monitor observations that infers the release timescales of relativistic SEPs at or near the Sun. With emphasis on SEP forecasting and data analysis, this book can both serve as a reference book and be used for space physics and space weather courses addressed to graduate and advanced undergraduate students. We hope the reader of this book will find the world of SEP events just as fascinating as we do ourselves. Olga E. Malandraki Norma B. Crosby Acknowledgements The HESPERIA project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 637324. The authors thank the EU for this support making it possible to further our knowledge in solar energetic particle research and forecasting, as well as write this book. The authors of Chaps. 4, 9 and 10 acknowledge the use of ERNE data from the Space Research Laboratory of the University of Turku and of the SEPEM Reference Data Set version 2.00, European Space Agency (2016). They thank the ACE/EPAM, SWEPAM and MAG instrument teams and the ACE Science Center for providing the ACE data. They acknowledge the use of publicly available data products from WIND/SWE and 3DP, GOES13/HEPAD and the CME catalogues from SoHO/LASCO and STEREO/COR1. SoHO is a project of international cooperation between ESA and NASA. They acknowledge also the use of the Harvard-Smithsonian Interplanetary shock Database maintained by M. L. Stevens and J. C. Kasper and of the Heliospheric Shock Database, generated and maintained at the University of Helsinki. Rolf Bütikofer thanks Erwin Flückiger and Claudine Frieden for their sug- gestions and assistance in writing Chaps. 5 and 6. This work was supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under the contract number 15.0233 and by the International Foundation High Altitude Research Stations Jungfraujoch and Gornergrat. The authors of Chap. 7 thank the National Oceanic Atmospheric Administration (NOAA) for providing GOES data files which were used to calibrate and evalu- ate the HESPERIA UMASEP-500 tool. They acknowledge the NMDB database (www.nmdb.eu) funded under the European Union’s FP7 programme (contract No. 213007). They also acknowledge Dr. Juan Rodriguez from NOAA for his support on the estimation of >500 MeV integral proton flux and expert advice on the GOES/HEPAD data. The authors of Chap. 8 acknowledge STEREO/HET/LET/SEPT, ACE/EPAM, ACE/SIS, GOES/HEPAD, WIND/3DP and SoHO/ERNE/EPHIN teams as well as the SEPServer team for the availability of the energetic particle data. The STEREO/SEPT and the SoHO/EPHIN projects are supported under grant vii viii Acknowledgements 50OC1702 by the Federal Ministry of Economics and Technology on the basis of a decision by the German Bundestag.