From the Magnetosphere to the Sun: How we Used Waves in Earth's Magnetosphere to Understand the Dynamic Nature of the Formation of the Slow Solar Wind
Abstract
Constant buffeting of Earth's magnetosphere by the highly dynamic solar wind produces a broad range of ULF oscillations in the mHz and sub mHz range (timescales of minutes to hours). Such oscillations have been observed for decades by in situ and ground-based observations. The magnetospheric boundaries are sharp and capable of reflecting oscillations, leading to the intriguing idea of cavity mode oscillations (standing mode waves), in which the magnetospheric cavity acts like a ringing bell, struck by the hammer that is the solar wind. As L1 solar wind measurements became more prevalent, it became clear that there were times when the magnetosphere was not ringing like a bell, but was directly driven by quasi-periodic dynamic pressure structures in solar wind that appeared to be ubiquitous - an unexpected finding. Yet, while this discovery answered one question, a major new question immediately arose: why are there quasi-periodic structures in the solar wind in the first place? And with that question, my career in heliophysics took a turn for the Sun to look for their source. In this talk, I discuss my research connecting the waves in the magnetosphere to quasi-periodic structures in the solar wind observed at L1, and further connecting those to the dynamic nature of the corona and of solar wind formation. We show that the slow solar wind in particular is released through magnetic reconnection with characteristic time scales. The result is quasi-periodic mesoscale structures in the slow solar wind that retain the magnetic and plasma signatures of this process, eventually driving magnetospheric pulsations several days later.
- Publication:
-
2018 Triennial Earth-Sun Summit (TESS)
- Pub Date:
- May 2018
- Bibcode:
- 2018tess.conf31001V