Japanese scientists have found out the frequency of solar flares that are dangerous for civil aviation.
Researchers from Japan have shown that the risk of exposing passengers and aircraft crews to high-energy solar particles is not high enough to take preventive measures. The work of the scientists is published in the journal Scientific Reports.
The main threat to radiation exposure in flight is galactic cosmic rays and high-energy solar particles. However, if the first ones are relatively stable — their dose in flight at an altitude of 12 kilometers does not exceed ten microsieverts per hour — then during strong bursts of solar cosmic rays, the radiation dose can exceed two millisieverts per hour. In such cases, the crews of civil flights are recommended to decrease or even stop flights.
Researchers from Kyoto University and the Japan Nuclear Energy Agency estimated the potential radiation doses during sudden solar radiation amplification of eight transcontinental flights. Then, based on data on recorded bursts of solar cosmic rays and information obtained based on an estimate of the concentration of cosmogenic nuclides, the scientists estimated the radiation dose received during them. It turned out that to take the recommended measures, the total dose of radiation received during the flight should be millisievert, or the irradiation should exceed 80 microsieverts per hour. However, an assessment of the frequency of such outbreaks shows that solar radiation amplification of such power occurs once in 47 and 17 years, respectively.