A Lookup Table To Compute High Energy Cosmic Ray Effects on Terrestrial Atmospheric Chemistry

Abstract

A variety of events such as gamma-ray and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have the capability of incorporating the effects of substantial cosmic ray flux above 10 GeV. An atmospheric code, the NASA-Goddard Space Flight Center two-dimensional (latitude, altitude) time-dependent atmospheric model (NGSFC), is used to study atmospheric chemistry changes. We have created a table that, with the use of the NGSFC code, can be used to simulate the effects of high energy cosmic rays (10 GeV - 1 PeV) ionizing the atmosphere. By interpolation, the table can be used to generate values for other uses which depend upon atmospheric energy deposition by ensembles of high-energy cosmic rays. We discuss the table, its use, weaknesses, and strengths.