Is it possible to organize automatic forecasting of expected radiation hazard level from Solar Cosmic Ray (SCR) events for spacecraft in the heliosphere and magnetosphere and for aircraft in the low Atmosphere?

Autor: Uri Dai, Lev Pustilnik, Mark Idler, Lev I. Dorman, Elizabeth Petrov, Fatima Keshtova
Rok vydání: 2019
Předmět:
Zdroj: Advances in Space Research. 64:2490-2508
ISSN: 0273-1177
Popis: We present method of automatically forecasting of Solar Cosmic Ray (SCR)/Solar Energetic Particle (SEP) impact and estimation of radiation hazard level. We use model of SCR/SEP diffusion in general form and coupling functions for neutron monitors of world-wide network with different altitudes and cut-off rigidities, including also space detectors like GOES-11, 12. Another observational data for estimation of energy spectra SCR/SEP are measurements of different neutron multiplicities by some neutron monitors (e.g., great SCR/SEP event at 29 September, 1989). For the highest energy SCR/SEP are useful also one minute data of muon telescopes and ionization chambers shielded by 10 cm PB (e.g., for SCR/SEP events like February 23, 1956 – see in Dorman, 1957 ). We demonstrate algorithms for automatic estimation of the event starting, determination time-evolution of SCR/SEP in space by coupling functions in the frame of spectrographic method, solving inverse problem for SCR/SEP generation in solar corona and propagation in the interplanetary space, automatic determining on the basis of CR observation data with determining parameters of SCR/SEP generation and propagation in solar corona, escaping into solar wind, and propagation in space. We show that on the basis of found parameters it can be automatic forecasting on the basis of first about 0.5 hour data on expected level of radiation hazards for full time of event (up to about 48 hours) for objects in space on different distances from the Sun, in magnetosphere at different orbits, and in atmosphere at different altitudes and cutoff rigidities. It is important, that before to calculate expected level of radiation hazards for full time of event, the Automatic Procedure each 5-10 minutes recalculated forecasting fluxes of SCR/SEP in space, out of magnetosphere, back to the CR ground detectors and detectors on satellites using the same coupling functions. If the difference of obtained results and really observed data became smaller or order of statistical errors, it can be shoe that the Automatic Procedure starts to give really good forecasting, and only after this can be calculated expected level of radiation hazards. If for some objects expected level of radiation hazards will be dangerous, after about 0.5 hour from event beginning will be formatted and sent corresponding Alert. More and more exactly Alerts will be repeated with time for different objects in space, in magnetosphere, and in atmosphere. We take into account that for the first about 0.5 hour data from event beginning, when are coming mostly high energy particles (with very small flux)– radiation hazards expected small in comparison with more delay time when coming main part of SCR/SEP with energy ≤ 1 GeV, formatted sufficient part of radiation hazards. We need to take into account also that at the beginning of some SCR/SEP events when the Earth is on or near the force line of IMF connected with the source of SCR/SEP, several CR stations with direct arriving along the magnetic force line with about no scattering SCR/SEP particles on magnetic inhomogeneities, will show strong narrow pulse with no information on SCR/SEP diffusion during the propagation from the source to the detector. These CR stations in beginning of SCR/SEP event can be used only for estimation of SCR/SEP energy spectrum in the source and time of injection into solar wind, but not on diffusion. So, it is necessary automatically to separate the CR stations with strong narrow pulses, and exclude them from diffusion analysis. We hope to make this automatically by using a program of image identification in the frame of Matlab.
Databáze: OpenAIRE
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