The Isotope Record of Diffusive Fractionation of Magnesium and Noble Gases in the Solar Wind and in Solar Flares

  D. E. Ragland and O. K. Manuel,

Chemistry Department,
 University of Missouri,
 Rolla, MO 65401

Isotopic analyses of Mg in the solar wind [Bochsler et al., 1995] and in solar flares [Selesnick et al., 1993] indicate changes by the same intra-solar diffusion processes found to enrich light elements and light isotopes of noble gases at the solar surface [Meteoritics 18, 209 (1983); J. Geophys. Res. 91, D473 (1986)]. Interference from hydride ions, e.g., MgH+, increases the uncertainty in isotopic abundances of solar Mg. Solar wind Mg is more closely approximated by a fractionated form of Mg observed in an inclusion of the Allende meteorite [Geophys. Res. Lett. 4, 299 (1977)] than by terrestrial Mg. Solar flares apparently disrupt diffusion and reduce the number of theoretical stages of mass fractionation. These results suggest that the solar surface may not be representative of the bulk Sun.