Prediction of Flight-Level Radiation Hazards Due To Solar Energetic Protons

The radiation environment at aircraft altitudes is caused primarily by high-energy particles originating from outside the near-earth environment. These particles generally come from outside our solar system and are called galactic cosmic rays. Occasionally however, a transient solar event will also accelerate energetic protons toward the earth. If these protons reach the upper atmosphere, they produce secondary particles via collisions, resulting in increased radiation levels in the atmosphere. Air crews and electronic systems flying at high altitudes during one of these events are subjected to these increased levels of radiation which can result in health problems for personnel and soft errors in electronics. Much work has been performed to calculate radiation dose rates at flight levels due to non-solar energetic particles, however very few dose rate measurements have been made shortly after the eruption of a large solar flare. Using energetic proton data measured at geosynchronous orbits and Monte Carlo transport codes, an attempt is made to estimate radiation dose rates at different altitudes and locations during solar events. The goal is to provide accurate information about the radiation environment at high altitudes, which will allow aircraft and personnel to avoid locations where health or the mission may be negatively impacted