Solar Wind Abundances of C and O

Quantitative understanding of solar wind (SW) elemental fractionation is required to improve knowledge of the solar nebula abundances from Genesis samples, in particular abundances of volatile elements, depleted in CI chondrites. Ratios of elements with low and high first ionization potential (FIP) in the solar wind, e.g., Fe/He, are higher than photospheric abundances. C, O, and N have intermediate FIP and are thus critical as to whether this fractionation is stepwise or gradual as a function of FIP.