Oxygen flux in the solar wind: Ulysses observations

• Published in: Geophysical research letters Vol. 37; no. 22; pp. np - n/a
• Main Authors: von Steiger, Rudolf, Zurbuchen, Thomas H., McComas, David J.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.11.2010; American Geophysical Union
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; Flux; Geophysics; Heliosphere; Latitude; Orbits; solar abundances; Solar activity; Solar wind; Spectroscopy; Heliosphere; Orbit; Coronal hole; abundance; solar activity; latitude; protons; oxygen; Lognormal distribution; solar wind
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2010GL045389

We use the complete set of Ulysses solar wind data to conduct a comprehensive determination of the oxygen flux in relation to the proton flux in the solar wind during a wide range of solar activity levels. The data cover the heliosphere between 1.3 and 5.4 AU and, due to the unique orbit of Ulysses, all of the heliographic latitudes within ±80°. We find log‐normal distributions for O and H daily flux values, but with significant differences between slow and fast wind. Coronal hole‐associated fast wind has a distribution that is approximately three times narrower than the one of slow wind associated with streamers. Finally, we derive the solar oxygen abundance, finding a value of 8.82 ± 0.08, and discuss this value in comparison with the results of spectroscopic determinations.