Study of Inverted-V Auroral Precipitation Events

  1. S.-I. Akasofu and
  2. J.R. Kan
  1. R. A. Hoffman1 and
  2. C. S. Lin2

Published Online: 26 MAR 2013

DOI: 10.1029/GM025p0080

Physics of Auroral Arc Formation

Physics of Auroral Arc Formation

How to Cite

Hoffman, R. A. and Lin, C. S. (1981) Study of Inverted-V Auroral Precipitation Events, in Physics of Auroral Arc Formation (eds S.-I. Akasofu and J.R. Kan), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM025p0080

Author Information

  1. 1

    Electrodynamics Branch, Goddard Space Flight Center, Greenbelt, Maryland 20771

  2. 2

    Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742

Publication History

  1. Published Online: 26 MAR 2013
  2. Published Print: 1 JAN 1981

ISBN Information

Print ISBN: 9780875900506

Online ISBN: 9781118664360



  • Auroras—Addresses, essays, lectures


A detailed survey of inverted-V events was made possible with the flight on the Atmosphere Explorer-D satellite of the Low Energy Electron Experiment (LEE), which contained an array of 19 charged particle detectors covering the energy range 200 eV to 25 keV. In this review the macroscopic properties of these events will be described first, including their spatial distributions and the extents of individual events. Statistical studies of microscopic characteristics include the distributions in energy and temperature of the monoenergetic components and systematics of the anisotropics in the pitch angle distributions.

A review of new work performed involves the relation of inverted-V events in the pre-midnight hours to magnetic activity. We conclude that inverted-V events are exceedingly common, so common, in fact, that they occur essentially all the time, independent of the state of magnetic activity. We further conclude that these analyses indicate that the basic mechanism for producing the inverted-V structure is nearly time stationary during the passage of the satellite through the event, and perhaps may not change significantly in location for much more extended periods.