Enhanced Radiation at Aviation Altitudes and Plasmaspheric Hiss Waves—A Time Shift Analysis

Abstract

Increased radiation levels in Earth's atmosphere can present significant risks to airline pilots, passengers, and commercial space travelers. Recent findings have revealed a strong statistical link between radiation dose rates detected at aviation altitudes ($>9$km) and plasmaspheric hiss wave power observed along the same magnetic field lines within the inner magnetosphere. Plasmaspheric hiss waves are crucial in depleting energetic electrons from Earth's radiation belts by causing them to precipitate into the upper atmosphere. In this study, we examine magnetic conjunction events between the Automated Radiation Measurements for Aerospace Safety (ARMAS) instruments and the Van Allen Probes to explore the relationship between plasmaspheric hiss waves and enhanced radiation at aviation altitudes. Specifically, we focus on how variations in conjunction timing, together with shifts in L-shell, and Magnetic Local Time influence the correlation between radiation dose rates and plasmaspheric hiss wave power. This investigation aims to determine whether the observed increase in radiation at aviation altitudes is directly linked to plasmaspheric hiss waves within the inner magnetosphere and to explore the extent to which enhanced radiation due to plasmaspheric hiss waves is localized in space and time. Results show that the strongest cross-correlation is only observed when plasmaspheric hiss waves and radiation doses occur nearly simultaneously and with close proximity. Spatiotemporal variations result in a degradation of the observed correlation.