Effects of Upstream Drivers on Magnetic Topology at VenusShow others and affiliations
2025 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 130, no 3, article id e2024JA033613Article in journal (Refereed) Published
Abstract [en]
Although Venus appears to present a predominantly ionospheric obstacle to the solar wind, the magnetic connectivity between the solar wind and the Venus ionosphere, or magnetic topology, is important for characterizing the Venus space environment. In particular, magnetic connectivity is relevant to the magnetization state of the ionosphere, particle precipitation into the atmosphere causing ionization and auroral emissions, and planetary ion escape at Venus. The spatial distributions of different magnetic topologies were statistically analyzed, with some unexpected results. Here, we build on those results by investigating how the external factors of solar cycle phase and upstream conditions affect the occurrence rates of the three magnetic topologies and consider their implications regarding the state of Venus's induced magnetosphere. We find that both the solar cycle phase and upstream dynamic pressure variations control its expansion or contraction. Under solar minimum conditions, the interplanetary magnetic field (IMF) more deeply penetrates into the collisional atmosphere, increasing the occurrence rates of open and closed topologies at low altitudes and in Venus's wake. We also find hemispheric differences in the occurrences of dayside-connected and nightside-connected open fields, likely related to mass loading of the near-Venus plasma environment by planetary pickup ions.
Place, publisher, year, edition, pages
American Geophysical Union (AGU), 2025. Vol. 130, no 3, article id e2024JA033613
Keywords [en]
Venus, induced magnetosphere, magnetic topology, solar wind interaction, superthermal electrons, Venus express
National Category
Fusion, Plasma and Space Physics Astronomy, Astrophysics and Cosmology Geophysics
Identifiers
URN: urn:nbn:se:uu:diva-553361DOI: 10.1029/2024JA033613ISI: 001440640200001OAI: oai:DiVA.org:uu-553361DiVA, id: diva2:1948107
2025-03-272025-03-272025-03-27Bibliographically approved