Estimation of Cosmic-Ray-Induced Atmospheric Ionization and Radiation at Commercial Aviation Flight Altitudes

Abstract

The main source of the ionization of the Earth’s atmosphere is the cosmic radiation that depends on solar activity as well as geomagnetic activity. Galactic cosmic rays constitute a permanent radiation background and contribute significantly to the radiation exposure inside the atmosphere. In this work, the cosmic-ray-induced ionization of the Earth’s atmosphere, due to both solar and galactic cosmic radiation during the recent solar cycles 23 (1996–2008) and 24 (2008–2019), was studied globally. Estimations of the ionization were based on the CRAC:CRII model by the University of Oulu. The use of this model allowed for extensive calculations from the Earth’s surface (atmospheric depth 1033 g/cm2) to the upper limit of the atmosphere (atmospheric depth 0 g/cm2). Monte Carlo simulations were performed for the estimation quantities of radiobiological interest with the validated software DYASTIMA/DYASTIMA-R. This study was focused on specific altitudes of interest, such as the common flight levels used by commercial aviation.

NMDB@Athens

“…Figure 6 presents time profiles of the annual values of CRII rate and ambient dose equivalent rate for the same period of time (year 1996 to 2019) for the three typical FLs and for four different geomagnetic cut-off rigidities (0.1 GV, 3.1 GV, 8.5 GV and 14.9 GV). It is observed that both CRII rate (blue lines, left axis) and ambient dose equivalent rate (red lines, right axis) follow an 11-year modulation, at all the locations, the same way the Galactic Cosmic Ray intensity does (Makrantoni et al 2021(Makrantoni et al , 2022Tezari et al 2022;Mavromichalaki et al 1995), as the intensity of the cosmic radiation directly affects the radiation exposure of the aircrew.…”

“…This fact is due to the CRII following the cosmic ray intensity behavior with which it is positively correlated, while it is negatively correlated with the solar activity. This means that the greater the solar activity, the lower the intensity of the CRII and vice versa Gleeson and Axford 1968;Mavromichalaki et al 1998;Makrantoni et al 2013Makrantoni et al , 2021Makrantoni et al , 2022.…”

The Atmospheric Influence on Cosmic-Ray-Induced Ionization and Absorbed Dose Rates

“…Many models have been developed to compute the ionization caused by cosmic rays in the atmosphere, such as PLANETOCOSMICS [18], CRAC:CRII [19], and others [20,21]. Recently, computations of the ionization rate were performed for the entire surface of the Earth at various altitudes during quiet periods and also for SEP events [22,23]. In addition to contributing to atmospheric ionization, cosmic rays lead to radiation exposure in the atmosphere.…”

The Updated Version of the A.Ne.Mo.S. GLE Alert System: The Case of the Ground-Level Enhancement GLE73 on 28 October 2021

“…These extreme events may be particularly harmful to technological infrastructure systems, both space-borne and terrestrial [16][17][18]. They may also pose a danger to human health, as far as astronauts and possibly aircrews are concerned [19][20][21][22][23].…”