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?

Abstract

We present the method of automatic forecasting of the impacts of Solar Cosmic Ray (SCR)/Solar Energetic Particle (SEP) and estimation of radiation hazard level. We use the model of SCR/SEP diffusion in general form and coupling functions for neutron monitors of worldwide network with different altitudes and cutoff rigidities, including space detectors such as GOES-11,12. Another observational data for the estimation of energy spectra of SCR/SEP are measurements of different neutron multiplicities by some neutron monitors (e.g., for great SCR/SEP event held in September 29, 1989). A 1-min data of muon telescopes and ionization chambers shielded by 10-cm PB are used for the detection of the highest-energy SCR/SEP components (e.g., for SCR/SEP events held on February 23, 1956; Dorman, 1957). We demonstrate algorithms to automatically estimate event starting times, determine the time evolution of SCR/SEP in space using coupling functions in the frame of spectrographic method, solve inverse problems associated with SCR/SEP generation in solar corona and propagation in the interplanetary space, automatically determine escaping into solar wind and propagation in space based on the CR observation data parameters of SCR/SEP generation and propagation in solar corona. Based on these parameters, we show that it is possible to automatically forecast the first 0.5 h data on expected level of radiation hazards from a full-time event (up to about 48 h) 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, before the start of the automatic forecasting procedure, to calculate the expected level of radiation hazards for full time of event by determining every 5–10 min 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 between the obtained results and observed data is smaller or no statistical errors, it is possible to provide effective forecasting automatically and subsequently calculate the expected level of radiation hazards. If the expected level of radiation hazards is high in certain objects, after about 0.5 h from the event starting time, it will be formatted and a corresponding alert is sent. The same alerts will be repeated with time for different objects in space, in magnetosphere, and in atmosphere. Based on the first 0.5 h data from event beginning, the radiation hazard level from high-energy particles such as SCR/SEP is considered to be low (with very small flux). If with increasing time the radiation hazard level rises with energy ≤1 GeV, it is formatted. Also, 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 at the beginning of the SCR/SEP event can be used only for estimating SCR/SEP energy spectrum in the source and at the time of injection into solar wind but not on diffusion. Hence, it is necessary to automatically separate the CR stations with strong narrow pulses and exclude them from diffusion analysis. We strive to make this automatic using a program of image identification in the frame of MATLAB.