NAIRAS aircraft radiation model development, dose climatology, and initial validation

Area of Science:

• Atmospheric physics
• Radiation dosimetry
• Aviation safety

Background:

• Commercial aircrews and passengers face radiation exposure during flights.
• Accurate real-time assessment of atmospheric ionizing radiation is crucial for aviation safety.
• Galactic Cosmic Rays (GCR) and Solar Energetic Particles (SEP) are primary radiation sources.

Purpose of the Study:

• Describe the NAIRAS GCR transport and dosimetry methodologies.
• Present a climatology of atmospheric dose rates at airline altitudes for solar cycle variations.
• Validate the NAIRAS model against existing radiation measurement data.

Main Methods:

• Utilized a global, physics-based, free-running model (NAIRAS).
• Predicted dosimetric quantities from GCR and SEP, including geomagnetic field responses.
• Compared NAIRAS predictions with reference measurements and 2008 aircraft data.

Main Results:

• NAIRAS GCR predictions are within 25% of measured data for doses >= 1 mSv annually, meeting ICRU uncertainty limits.
• Single-point comparisons show NAIRAS predictions within 50% of measured data.
• Model improvements are expected with a new pion-initiated cascade code integration.

Conclusions:

• The NAIRAS model provides a reliable assessment of atmospheric GCR exposure for aviation safety.
• The model's current performance aligns with acceptable radiation dose uncertainty criteria.
• Ongoing development aims to further enhance the accuracy of radiation dose predictions.