Spatial Distribution of Element Abundances and Ionization States in Solar Energetic-Particle Events

Spatial Distribution of Element Abundances and Ionization States in Solar Energetic-Particle Events We have studied the spatial and temporal distribution of abundances of chemical elements in large “gradual” solar energetic-particle (SEP) events, and especially the source plasma temperatures, derived from those abundances, using measurements from the Wind and Solar TErrestrial RElations Observatory (STEREO) spacecraft, widely separated in solar longitude. A power-law relationship between abundance enhancements and mass-to-charge ratios [ A / Q $A/Q$ ] of the ions can be used to determine Q $Q$ -values and source plasma temperatures at remote spacecraft with instruments that were not designed for charge-state measurements. We search for possible source variations along the accelerating shock wave, finding one clear case where the accelerating shock wave appears to dispatch ions from 3.2 ± 0.8 MK $3.2\pm 0.8~\mbox{MK}$ plasma toward one spacecraft and those from 1.6 ± 0.2 MK $1.6\pm 0.2~\mbox{MK}$ plasma toward another, 116∘ away. The difference persists for three days and then fades away. Three other SEP events show less-extreme variation in source temperatures at different spacecraft, in one case observed over 222∘ in longitude. This initial study shows how the power-law relation between abundance enhancements and ion A / Q $A/Q$ -values provides a new technique to determine Q $Q$ and plasma temperatures in the seed population of SEP ions over a broad region of space using remote spacecraft with instruments that were not originally designed for measurements of ionization states. Solar Physics Springer Journals

Spatial Distribution of Element Abundances and Ionization States in Solar Energetic-Particle Events

Solar Physics , Volume 292 (8) – Aug 11, 2017

Loading next page...
Springer Netherlands
Copyright © 2017 by Springer Science+Business Media B.V.
Physics; Astrophysics and Astroparticles; Atmospheric Sciences; Space Sciences (including Extraterrestrial Physics, Space Exploration and Astronautics)
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial