Analytical Representations for Characterizing the Global Aviation Radiation Environment Based on Model and...

Area of Science:

• Aerospace Engineering
• Radiation Physics
• Atmospheric Science

Background:

• The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety model and the Automated Radiation Measurements for Aerospace Safety (ARMAS) database provide crucial data for understanding aviation radiation environments.
• Galactic cosmic rays (GCR) and relativistic energetic particles (REP) contribute to the ionizing radiation exposure experienced by aircrews and passengers.
• Existing models may not fully account for the combined effects of GCR and REP, particularly in specific L-shell ranges.

Purpose of the Study:

• To present polynomial fit equations for the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety model and the ARMAS statistical database.
• To enable calculation of effective dose rates from GCR and REP environments based on altitude, L shell, and geomagnetic conditions.
• To investigate the potential contribution of REP to radiation exposure at aviation altitudes.

Main Methods:

• Development of polynomial fit equations using altitude, L shell, and geomagnetic conditions.
• Utilizing a subset of the ARMAS database to represent GCR plus probable REP effective dose rates.
• Analyzing Western Hemisphere observations within L shells 1.5 to 5.

Main Results:

• Effective dose rates from GCR environments can be calculated using the derived equations.
• A combined GCR and REP effective dose rate equation was developed for specific L shell ranges.
• The study identified that combined radiation effects in the analyzed L shell range are approximately 15% higher than GCR background alone.
• Solar energetic particle events were excluded from this analysis.

Conclusions:

• The derived polynomial equations provide a valuable tool for assessing atmospheric ionizing radiation for aviation safety.
• There is evidence suggesting a REP contribution to radiation exposure at aviation altitudes, particularly within specific L shell ranges.
• The ARMAS database and derived equations have applications in radiation climatology, nowcasting, forecasting, and air traffic management.