Numerical model for computation of effective and ambient dose equivalent at flight altitudes

Abstract

A numerical model for assessment of the effective dose and ambient dose equivalent produced by secondary cosmic ray particles of galactic and solar origin at commercial aircraft altitudes is presented. The model represents a full chain analysis based on ground-based measurements of cosmic rays, from particle spectral and angular characteristics to dose estimation. The model is based on newly numerically computed yield functions and realistic propagation of cosmic ray in the Earth magnetosphere. The yield functions are computed using a straightforward full Monte Carlo simulation of the atmospheric cascade induced by primary protons and a-particles and subsequent conversion of secondary particle fluence (neutrons, protons, gammas, electrons, positrons, muons and charged pions) to effective dose or the ambient dose equivalent. The ambient dose equivalent is compared with reference data at various conditions such as rigidity cut-off and level of solar activity. The method is applied for computation of the effective dose rate at flight altitude during the ground level enhancement of 13 December 2006. The solar proton spectra are derived using neutron monitor data. The computation of the effective dose rate during the event explicitly considers the derived anisotropy i.e. the pitch angle distribution as well as the propagation of the solar protons in the magnetosphere of the Earth.

In Situ Data and Effect Correlation During September 2017 Solar Particle Event

“…On the basis of derived spectra using neutron monitor data and employing a recent model (Mishev & Usoskin, ), we computed the effective dose rate during the event at several commercial flight altitudes, the details are given in this volume (Mishev & Usoskin, ). An example of the effective dose rate distribution at an altitude of 40,000 feet (12.2 km) above sea level during the peak intensity of GLE 72 is given in Figure .…”

Assessment of the Radiation Environment at Commercial Jet‐Flight Altitudes During GLE 72 on 10 September 2017 Using Neutron Monitor Data

“…The integration is over the kinetic energy above T cut, i ( P cut ), which is defined by P cut for a nuclei of type i . The full description of the model with the corresponding look‐up tables of the yield functions at several altitudes asl and comparison with reference data is given elsewhere (Mishev & Usoskin, ).…”

“…Here we computed the effective dose rates during GLE 72 at several cruise flight altitudes. We employed a recently developed model and procedure, the details are given in Mishev and Usoskin () and Mishev et al (). We calculated the exposure over the globe and the received doses of crew members/passengers for typical intercontinental flights.…”

Preface to measurement, specification and forecasting of the Solar Energetic Particle (SEP) environment and Ground Level Enhancements (GLEs)

“…On the basis of worldwide NM database records and a convenient optimization procedure, the spectral and angular characteristics of sub-GLE particles are assessed. Subsequently, using a recent model (Mishev & Usoskin, 2015) the radiation exposure at typical commercial flight cruise altitudes of 35 000 feet above sea level during these events is estimated. This further demonstrates that the global NM can be used to address important space weather issues related to alert signals and assessment of radiation environment in near Earth space and Earth's atmosphere (e.g.…”