Eclipse-Induced Changes to Topside Ion Composition and Field-Aligned Ion Flows in the August 2017 Solar Eclipse: e-POP Observations

Andrew W. Yau, Victoria Foss, Andrew D. Howarth, Gareth W. Perry, Christopher Watson, Joseph Huba

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

We present in situ ion composition and velocity measurements during the August 2017 solar eclipse from the Enhanced Polar Outflow Probe (e-POP), which crossed the path of totality at ~640-km altitude within 10 min of totality passing. These measurements reveal two distinct H+ ion populations, an ~40% decrease in topside plasma density, a similar drop in upward but not downward H+ ion flux, and a downward O+ ion velocity of ~100 m/s. These features are directly linked to changes in the H+/O+ composition and in interhemispheric or field-aligned light ion flow and to a reduction in the negative spacecraft potential. These observed features were absent on the preceding, noneclipse days and corroborate the reduction in F region plasma density and topside total electron content observed by the Global Positioning System receivers on board. They are attributed to the temporary reduction of photoionization in the eclipsed F region.

Original languageEnglish (US)
Pages (from-to)10,829-10,837
JournalGeophysical Research Letters
Volume45
Issue number20
DOIs
StatePublished - Oct 28 2018
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Geophysics
  • General Earth and Planetary Sciences

Keywords

  • ion composition
  • ion flow
  • ionosphere
  • mass spectrometer
  • plasma density
  • solar eclipse

Fingerprint

Dive into the research topics of 'Eclipse-Induced Changes to Topside Ion Composition and Field-Aligned Ion Flows in the August 2017 Solar Eclipse: e-POP Observations'. Together they form a unique fingerprint.

Cite this