HESPERIA Forecasting Tools: Real-Time and Post-Event

Abstract

Within the HESPERIA Horizon 2020 project, two novel real-time tools to predict Solar Energetic Particle (SEP) events were developed. The HESPERIA UMASEP-500 tool makes real-time predictions using a lag-correlation between the soft X-ray (SXR) flux and high-energy differential proton fluxes of the GOES satellite network. We found that the use of proton data alone allowed this tool to make predictions before any Neutron Monitor (NM) station's alert. The performance of this tool for predicting Ground Level Enhancement (GLE) events for the period 2000-2016 may be summarized as follows: the probability of detection (POD) was 53.8%, the false alarm ratio (FAR) was 30%, and the average warning time (AWT) to the first NM station's alert was 8 min. The developed HESPERIA REleASE tool makes real-time predictions of the proton flux-time profiles of 30-50 MeV protons at L1 and is based on electron intensity measurements of energies from 0.25 to 1 MeV and their intensity changes. The performance was tested by using all historic ACE/EPAM and SOHO/EPHIN data from 2009 until 2016 and has shown that the forecast tools have a low FAR ( 30%) and a high POD (63%). Furthermore, two methods using historical data were explored for predicting SEP events and M. Núñez ( ) • P. Reyes-Santiago

The Electron Proton Helium INstrument as an example for a Space Weather Radiation Instrument

“…The photons stem from an X2.6 x-ray flare located at S10 and W30 that had an onset, maximum and end time at 09:01 UT, 09:12 UT and 09:49 UT, respectively (from ftp://ftp.ngdc.noaa.gov/STP/space-weather/solardata/solar-features/solar-flares/x-rays/goes/xrs/). These capabilities of detecting solar flare photons can be exploited for studies on and/or forecasting schemes (see for example Núñez et al, 2018, and references therein). It has to be noted, however, that the flare signal presented in Figure 5 was measured during an early phase of the mission.…”

Predicting well-connected SEP events from observations of solar EUVs and energetic protons

“…Also note that these metrics do not count the number of intermediate events that are analyzed to make predictions, such as the number of flares. For more information about how FAR all and POD all are calculated for assessing >10 MeV SEP event predictors, please consult Balch (2008), Laurenza et al (2009) and Núñez et al (2018). Table 10 shows that the FAR all of the UMASEP-10's PCP model is high (44.4%) and the POD all is very low (35.7%); however, the POD non-prompt is 100% (10/10) for the analyzed period, making the PCP model a very good complement of all the WCP models, which is the main reason why the ensemble WCP + PCP has satisfactory results in terms of the POD all in all the UMASEP-based tools presented in Table 10.…”

Predicting well-connected SEP events from observations of solar soft X-rays and near-relativistic electrons

“…If the solar EM peak flux of the associated flare is greater than a certain threshold, an SEP event prediction is triggered. Regarding solar EM data, the UMASEP's WCP scheme has been used with SXR flux (Núñez 2011(Núñez , 2015Núñez et al 2017Núñez et al , 2018, and microwave (MW) flux density at 5 and 9 GHz (Zucca et al 2017). Regarding in situ particle data, the WCP scheme has been used with proton data only; however, in this paper we evaluate for the first time the use of electron data in this scheme.…”

“…REleASE (Relativistic Electron Alert System for Exploration) (Posner 2007) uses this effect to predict the 30-50 MeV proton flux by utilizing actual electron fluxes with energies of 0.25-1.0 MeV from the Electron Proton Helium Instrument (EPHIN) on board the Solar and Heliospheric Observatory (SOHO). Since EPHIN data has a limited time coverage in real-time data, the REleASE scheme was used in the HESPERIA project (Malandraki & Crosby 2018;Núñez et al 2018) with real-time electron intensities in the energy range 0.175-0.315 MeV from the Electron Proton Alpha Monitor (EPAM) on board the Advanced Composition Explorer (ACE).…”

“…The evaluation of this scheme has shown good forecasting performance in terms of Probability of Detection (POD) (in the range of 81%-88%) and False Alarm Ratio (FAR) (the range of 23%-34%); however the Average Warning Time (AWT) was not as good as those obtained with the use of electron data by the REleASE scheme. The UMASEP scheme has been used to develop several real-time prediction tools: UMASEP-10 (Núñez 2011), UMASEP-100 (Núñez 2015) and HESPERIA UMASEP-500 (Núñez et al , 2018 which predicts >10 MeV, >100 MeV and >500 MeV SEP events, respectively. Since 2010, the NASA's integrated Space Weather Analysis (iSWA) system redistributes UMASEP-10's forecasts, which have obtained successful results on an operational level (Tsagouri et al 2013).…”