Modeling approaches for forecasting of solar proton events
Abstract
Solar proton events (SPEs) constitute a major radiation hazard for interplanetary and near-Earth space manned flights. Hence, a warning system is required in order to predict SPEs occurrence and start the appropriate procedures to mitigate their effects. The state-of-the-art modelling approaches for SPE forecasting/nowcasting will be presented and discussed in this talk. The majority of such models are designed to predict SPEs with peak intensity > 10 pfu (i.e., ≥S1 events, where S1 refer to minor storms on the NOAA Solar Radiation Storms scale), i.e., all SEP events independently of their radiation level. The NOAA space weather scale includes four additional categories: moderate (S2), strong (S3), severe (S4), and extreme (S5). As S1 events have only minor impacts on HF radio propagation in the polar regions, the effective threshold for significant space radiation effects appears to be the S2 level (100 pfu), above which large biological impacts are observed. The ESPERTA (Empirical model for Solar Proton Event Real Time Alert) model was developed to provide early forecasts of ≥S1 SPEs, based on the associated flare size, longitude and evidence of particle escape. ESPERTA was also adapted to predict the largest radiation storms, produced by ≥S2 SEP events, and validated by considering the proton flux level over an extended SPEs dataset, covering the period 1995-2014, obtaining the following verification measures: probability of detection of 75% and a false alarm rate of 23% for the 1995-2017 interval with a median (minimum) warning time of $\sim$1.7 ($\sim$0.2) h based on predictions made at the time of the S1 threshold crossing. Its basics and the possible application onboard for effective mitigation of SPEs event impacts, as well as possible future enhancements are also discussed.
- Publication:
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43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E1841L