Paper presented at the AGU Spring Meeting, 27-30, May, 1997, Baltimore, USA
Using the data from the CELIAS/MTOF sensor on SOHO, we discuss the importance of isotope fractionation processes in the solar wind. The discussion begins with a comparison of solar wind data and meteoritic isotope abundances of refractory elements. Further clues on the efficiency of the isotope fractionation in the solar wind are obtained from the variation (or absence of variation) of certain reference isotope abundance ratios in the context of varying solar wind regimes. We then try to estimate the magnitude of isotope fractionation processes due to gravitational settling in the outer convective zone of the sun, due to ion-neutral fractionation in the upper chromosphere, and finally, due to inefficient Coulomb drag in the corona. Isotope fractionation in the solar wind can be relevant for geochemical and cosmochemical applications and for future space missions such as ACE and GENESIS.