2023/09/20 by L. B. Wilson, C. S. Salem, Wilson, L. B. +3 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Geophysics and Gravity Measurements #Ionosphere and magnetosphere dynamics #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2309.11626
openalex publication_date 2023/09/20 · openalex created_date 2023/09/23 · openalex updated_date 2026/07/28
Analysis of 8,804,545 electron velocity distribution functions (VDFs), observed by the Wind spacecraft near 1 AU between January 1, 2005 and January 1, 2022, was performed to determine the spacecraft floating potential, ϕ\scriptstylesc. Wind was designed to be electrostatically clean, which helps keep the magnitude of ϕ\scriptstylesc small (i.e., ∼5--9 eV for nearly all intervals) and the potential distribution more uniform. We observed spectral enhancements of ϕ\scriptstylesc at frequencies corresponding to the inverse synodic Carrington rotation period with at least three harmonics. The 2D histogram of ϕ\scriptstylesc versus time also shows at least two strong peaks with a potential third, much weaker peak. These peaks vary in time with the intensity correlated with solar maximum. Thus, the spectral peaks and histogram peaks are likely due to macroscopic phenomena like coronal mass ejections (solar cycle dependence) and stream interaction regions (Carrington rotation dependence). The values of ϕ\scriptstylesc are summarized herein and the resulting dataset is discussed.