Determining the Elemental and Isotopic Composition of the preSolar Nebula from Genesis Data Analysis: The Case of Oxygen

TL;DR

This study compares solar wind element and isotope fractionations from Genesis data with models, providing insights into the pre-Solar nebula's composition, especially oxygen, and supporting the role of specific physical processes in solar wind fractionation.

Contribution

It offers the first detailed comparison of Genesis solar wind data with models including ponderomotive force and adiabatic invariance, refining our understanding of solar wind fractionation and elemental abundances.

Findings

Good agreement between measurements and models.

Support for oxygen abundance between 8.75 and 8.83.

Disfavoring of oxygen abundance as low as 8.69.

Abstract

We compare element and isotopic fractionations measured in solar wind samples collected by NASA's Genesis mission with those predicted from models incorporating both the ponderomotive force in the chromosphere and conservation of the first adiabatic invariant in the low corona. Generally good agreement is found, suggesting that these factors are consistent with the process of solar wind fractionation. Based on bulk wind measurements, we also consider in more detail the isotopic and elemental abundances of O. We find mild support for an O abundance in the range 8.75 - 8.83, with a value as low as 8.69 disfavored. A stronger conclusion must await solar wind regime specific measurements from the Genesis samples.