The sensitivity of satellite communications to the uncertainties in selected chemical reaction rate coefficients

The relative importance of various reaction rates are examined using the results of a recent MELT code calculation for a megaton range burst at 250 km altitude. New rate coefficients are developed for the critical reactions involved in the ion decay and the uncertainties in these rate coefficients are examined. With the use of a number of assumptions, some of them rather crude, these rate coefficient uncertainties are translated into uncertainties in communications degradation effects for HF and higher frequencies and some of these are significant. Areas in which improvement is needed, with regard to both reaction rate data and the chemistry treatment in MELT, are noted.