Solar Energetic Electrons and Radio Emission Signatures Susan W. Samwel samwelsw@nriag.sci.eg National Research Institute of Astronomy and Geophysics (NRIAG), 11421, Helwan, Cairo, Egypt Rositsa Miteva Space Research and Technology Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

SEPs are generated by solar activity (flares, CMEs) (ongoing debate)?? Introduction Solar energetic particle (SEP) is a generic term used to describe an elevated flux of electrons, protons and heavy ions that are energized during eruptive event at the Sun to keV -GeV and observed in situ CME flare SEPs are generated by solar activity (flares, CMEs) (ongoing debate)?? source surface SEPs in situ solar energetic particles, particles/(cm2 sr s MeV) Energetic particles escape from the corona, sustain various transport effects in the IP space before being finally detected.

Introduction Solar Energetic Particle Catalogs …Why?? Solar energetic particles (SEPs) are an important aspect of space weather research due to the potential radiation risk they carry. planning and carrying out of human flights to space require an improved knowledge and successful forecasting of the energetic protons and electrons released from the Sun. Solar Energetic Particle Catalogs …Why?? Solar Energetic Proton Catalogs http://newserver.stil.bas.bg/SEPcatalog/index.html Miteva, R., Samwel, S.W. & Costa-Duarte, M.V. Sol Phys (2018) 293: 27. https://doi.org/10.1007/s11207-018-1241-5 VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Novel Solar Energetic Electron Catalog?? Solar Energetic Electron Catalogs Lists No. of events/Energy instrument Duration Krucker et al. (1999) 12 events (< 1keV) 58 events (>25 keV) Wind /3-DP Haggerty and Roelof (2002) 79 events (38-315 keV) ACE/EPAM Aug. 1997-Sep. 2000 Krucker et al. (2007) 16 events (>50keV) 2002-2005 Vainio et al., 2013 SEPServer Cat. 315 events SOHO/EPHIN 1996-2010 Novel Solar Energetic Electron Catalog?? VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Onset time: 3σ above background level ACE/EPAM Electron Events Catalog Data Analysis Instrument: Electron Proton and Alpha monitor (EPAM) aboard the ACE spacecraft Time coverage: 1997–2017 Resolution: 12 sec Energy range: 103–175 keV (low) 175–315 keV (high) Onset time: 3σ above background level Peak intensity, Je: electrons/cm2 sr s keV ~1240 electron events ~990 electron events CDAW database for ACE/EPAM data: http://cdaweb.gsfc.nasa.gov/ VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

ACE/EPAM Electron Event Catalog keV)-1 http://www.nriag.sci.eg/aceepam-electron-event-catalog-2/ -GOES Soft X-ray flare listing, - Solar monitor.org - SGD reports SOHO/LASCO catalog VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Distribution of electron events over SC23 Electron events (SC23) 103–175 keV: 840 events 175–315 keV: 680 events Electron events (SC24) 103–175 keV: 407 events 175–315 keV: 319 events Solar origin identification (SC23) Flares: 66% CMEs: 55% Solar origin identification (SC24) Flares: 82% CMEs: 76% VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Cross-Correlation plot of electrons and protons Good correspondence between the electron and proton signatures of the same eruptive event: e-p pair is performed under the condition for the same solar origin small sample (172 events (SC23) & 93 events (SC24)) due to the fewer proton cases observed VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

correlation with flare class SC23 SC24 k k k k VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

correlation CME speed SC23 SC24 k k k k VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

We aim to finally bridge this gap Radio Emission Signatures Catalog Motivation The radio emissions considered as the signatures of in situ observed particles are always compared to the occurrences and peak intensities of protons and not to electrons (e.g. Kahler, 1982; Chertok, 1990; Miteva, Klein, Samwel, …et al., 2013; Miteva, Samwel, Krupar., 2017) We aim to finally bridge this gap VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Sources Radio Emission Signatures Catalog Radio observatory frequency range, MHz Data link Ondrejov 800–5000 http://www.asu.cas.cz/∼radio/info.htm e-Callisto/Phoenix 10–5000 http://soleil.i4ds.ch/solarradio/callistoQuicklooks/ http://soleil.i4ds.ch/solarradio/data/1998–2009_quickviews/ HiRAS 25–2500 http://sunbase.nict.go.jp/solar/denpa/index.html Culgoora 18–1800 http://www.sws.bom.gov.au/World_Data_Centre/1/9 Green Bank 5–1100 http://www.astro.umd.edu/∼white/gb/index.shtml Radio Monitoring 0.02–1000 http://secchirh.obspm.fr/select.php ARTEMIS 20–600 http://artemis-iv.phys.uoa.gr/Artemis4_list.html IZMIRAN 25–270 http://www.izmiran.ru/stp/lars/s_archiv.htm Bruny Island 6–62 http://www.astro.umd.edu/white/gb/index.shtml Wind/WAVES 0.02–14 https://solar-radio.gsfc.nasa.gov/wind/data_products.html STEREO/WAVES 0.02–16 RSTN (Sagamore Hill, Palehua, Learmonth, and San Vito) 245, 410, 608, 1415, 2695, 4995, 8800, & 15400 ftp://ftp.ngdc.noaa.gov/STP/space-weather/solar-data/solar-features/solar-radio/rstn-1-second/ VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Radio Emission Signatures Catalog http://newserver.stil.bas.bg/SEPcatalog/index.html Disclaimer: The radio catalog is still under construction! VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Preliminary results: Analysis of RSTN observatory reports as provided by SWPC (1997–2017) Increasing trend of the Pearson correlation coefficients with the increase of the radio emission frequency of the electron-related flare, apart from the 15.4 GHz. The correlations for the 2695–8800 MHz emission are statistically larger compared to the cases when GOES SXR flare class and CME projected speed is considered. The differences between low (245 MHz) and higher frequencies (2695–8800 MHz) are statistically significant. The trend is kept when the correlations are done both for low and high energy electron fluxes VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Preliminary results (for both catalogs) Miteva R., Samwel S.W., Danov D., “Catalogs of Solar Energetic Electrons and Their Radio Emissions in Solar Cycles 23 and 24”, Proceeding of the Fourteenth International Scientific Conference Space, Ecology, Safety SES 2018. http://195.96.250.194/BG/magasin/SES/PROCEEDINGS%20SES%202018.pdf Ongoing and Future Work Continue compiling both ACE/EPAM electron event catalog and Radio emission signature catalog Perform Statistical analysis of the solar energetic electron events and their solar origin, in addition to the corresponding radio signatures . Our results will be freely released to the community following their perspective publications VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Acknowledgement SCOSTEP VarSITI scientific program under ISEST/Minimax24 with the project ‘Solar energetic electrons and radio emission signatures’ (Variability of the Sun and Its Terrestrial Impacts: www.varsiti.org) VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria

Thank You VarSITI Closing Symposium, June 10-14, 2019, Sofia, Bulgaria