Results from the NAIRAS model for the Halloween Storms

In this presentation we discuss the results from the Nowcast of Atmospheric

Ionizing Radiation for Aviation Safety (NAIRAS) model during the Halloween 2003

superstorm. NAIRAS's goal is to provide global, real-time, data driven

predictions of ionizing radiation at commercial airline altitudes for assessing

the biologically harmful radiation exposure. The modeling system combines

numerical and empirical models of the geospace environment with particle tracing

technologies to predict the regions of energic particle access across the

global. This information is then passed to a radiation transport simulation to

compute the dose at atmospheric altitudes. We have used the observations of the

solar energic particle fluxes and solar wind conditions to drive the model

during the Halloween 2003 superstorm and find significant increases in exposure

risk at high-latitude flights especially for flights during the storm that

approached ionospheric foot points of the magnetospheric open-closed field line

boundary.