Forecasting the arrival of fast coronal-mass ejecta at Earth by the detection of 2-20keV neutral atoms

Ke C. Hsieh, K. L. Shih, David J. McComas, S. T. Wu, C. C. Wu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations

Abstract

Studies have show that Earth passages of fast coronal mass ejections (CMEs) trigger geomagnetic storms. Early identification of fast Earth-directed CME can help provide storm warnings, but detection of such by coronagraphs is extremely difficult. We suggest that energetic hydrogen atoms (EHA) between 2 and 10 keV produced during the transit phase of an Earth-directed CME by recombination between protons and electrons in the CME can travel ahead of the CME and act as harbingers of a magnetic storm. This forecasting scheme should work if enough EHA are produced, because while CMEs decelerate continuously after their ejection, the EHA fluxes produced in the initial phase of fast CMEs propagate at their initial high speeds (> 1 × 103 km s-1). Model simulations support this proposed mechanism. A coarse measurement of the CME-produced ENA at 1 AU could provide storm warning hours in advance, and finer measurements could yield detailed information on the likely geomagnetic effectiveness of a CME, as well as the evolution and propagation of CME between the Sun and Earth.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Int Soc for Optical Engineering
Pages72-78
Number of pages7
ISBN (Print)0819409170
StatePublished - 1992
Externally publishedYes
EventInstrumentation for Magnetospheric Imagery - San Diego, CA, USA
Duration: Jul 19 1992Jul 19 1992

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume1744
ISSN (Print)0277-786X

Conference

ConferenceInstrumentation for Magnetospheric Imagery
CitySan Diego, CA, USA
Period7/19/927/19/92

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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