12-20 July 2017
BEXCO
Asia/Seoul timezone
Home > Timetable > Session details > Contribution details

Contribution

BEXCO - Room C(108)

[SH163] Forward to automatic forecasting of expected radiation hazards from SEP events for space- and air-crafts

Speakers

  • Lev DORMAN

Primary authors

  • Lev DORMAN (Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation RAN of N.V. Pushkov (IZMIRAN), Russia)

Description

In the last years became possible to have on-line through Internet one-minute cosmic ray (CR) data from many neutron monitors and muon telescopes (in high energy region) as well as from several spacecrafts (in very low energy region). To avoid damage of electronics and negative effects for people health is necessary on-line forecast expected fluency of energetic particles and radiation hazards. It was shown by myself and colleagues in many original research papers that this possible to do by using the first 20-30 minutes of CR data on the basis of coupling functions, spectrographic method, and by solving inverse problem, and then calculate expected results on radiation hazards for many hours of Solar Energetic Particle (SEP) event. Usually it takes a lot of time (at least, several months). But for real all this must be made automatically, including the formation of corresponding alerts on the expected level of radiation hazard for different objects. We describe several automatically worked stages and obtain corresponding algorithms. The first stage works continue, collecting from Internet all available one minute data on CR variations (corrected on meteorological and geomagnetic effects). The second stage also works continue according to automatically working program "SEP-Start" - supposed, developed and checked in the Israel Cosmic Ray and Space Weather Centre. Using of this program on many CR stations and on satellites allowed to determine automatically the beginning of SEP event (it can be different at different stations caused to anisotropy at beginning of SEP). If the second stage gives positive result, starts to work automatically the third stage according to program "SEP-Coupling" – using method of coupling functions and spectrographic method for transformation obtained at different altitudes and cutoff rigidities data on CR intensity variations to the space and calculation CR energy spectrum and angle distribution out of the Earth’s atmosphere and magnetosphere, directly in the interplanetary space near the Earth. After obtaining results by third stage starts to work automatically the fourth stage according to program "SEP-Inverse Problem", and it is determined source function, time of ejection SEP into interplanetary space, and diffusion coefficient of propagation in dependence of SEP energy and distance from the Sun. After obtaining results by fourth stage starts to work automatically the fifth stage according to program "SEP-Direct Problem", and it is determined by found at fourth stage parameters the time variations of primary SEP in dependence of particles energy in interplanetary space near the Earth for many hours ahead, up to few days (on the basis of only 20-30 minutes of SEP beginning). On the basis of information, obtained in the fifth stage, it is easy to calculate by known coupling functions and cutoff rigidities expected time variations of SEP intensity in SPACE- and AIR-CRAFTS at different trajectories, and compare the beginning part with available observations and estimate the quality of forecasting (sixth stage, program “SEP-Forecasting”). If the forecasted radiation hazard is expected dangerous for different objects, will be immediately send corresponding Alerts (seventh stage, program “SEP-Alerts”). By obtaining new data, forecasting Alerts became more and more exactly. We prepared all algorithms to realize this program automatically. We consider also how to extend the program for more complicated cases, including anisotropic SEP events.