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Title: Multipoint study of a substorm on February 9, 1995

Abstract

An extended interval of strong northward interplanetary magnetic field (IMF) was observed by the Wind spacecraft located at an upstream distance of {approximately}193 R{sub E} from February 8{endash}10, 1995, with a brief break of southward IMF from 0200 to 0400 UT on February 9. This brief interval of southward IMF led to an isolated substorm of moderate intensity ({approximately}500 nT) with expansion phase starting at {approximately}0431 UT. This substorm may be triggered by the northward turning of the IMF since its onset time matched well with the time expected for the arrival of the northward turning of the IMF at Earth. The substorm activities were monitored by 11 spacecraft in space (Wind, IMP 8, Geotail, six geosynchronous satellites, one DMSP satellite, and Freja) and two networks of ground stations (Canopus and SuperDARN) covering both the northern and southern hemispheres. The extensive coverage of this event provides us with results (1) showing some unusual characteristics possibly related to the isolated nature of the substorm and (2) revealing some surprising features difficult to reconcile with the traditional substorm model. In the first category is unusually long duration of the growth phase and the long time delay between substorm expansion onset and particlemore » injection onset at the geosynchronous orbit. In the second category is new evidence for multiple particle acceleration sites during substorm expansion and for sunward flow during the late expansion phase of a substorm being unrelated to a single acceleration site ({ital X} line) moving from the near-Earth tail to the more distant tail. We also present observations which show the possible optical signature on the ground of bursty bulk flows in the magnetotail. {copyright} 1998 American Geophysical Union« less

Authors:
; ; ; ; ; ; ;  [1];  [2]; ; ;  [3];  [4]; ; ;  [5]; ;  [6]; ;  [7] more »;  [8];  [9];  [10] « less
  1. Applied Physics Laboratory, The Johns Hopkins University, Laurel, Maryland (United States)
  2. Department of Physics Astronomy, University of Maryland, College Park (United States)
  3. Institute of Space and Astronautical Science, Sagamihara, Kanagawa (Japan)
  4. Solar Terrestrial Environment Laboratory, Nagoya University, Toyokawa (Japan)
  5. Radio Atmospheric Science Center, Kyoto University, Kyoto (Japan)
  6. NASA Goddard Space Flight Center, Greenbelt, Maryland (United States)
  7. Department of Physics, University of Alberta, Edmonton, Alberta (Canada)
  8. Los Alamos National Laboratory, Los Alamos, New Mexico (United States)
  9. British Antarctic Survey, Cambridge, England (United Kingdom)
  10. Space Environment Center, National Oceanic and Atmospheric Administration, Boulder, Colorado (United States)
Publication Date:
OSTI Identifier:
298591
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research
Additional Journal Information:
Journal Volume: 103; Journal Issue: A8; Other Information: PBD: Aug 1998
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; EARTH MAGNETOSPHERE; SOLAR WIND; MAGNETIC STORMS; INTERPLANETARY MAGNETIC FIELDS; SPACE VEHICLES

Citation Formats

Lui, A T, Williams, D J, McEntire, R W, Ohtani, S, Zanetti, L J, Bristow, W A, Greenwald, R A, Newell, P T, Christon, S P, Mukai, T, Tsuruda, K, Yamamoto, T, Kokubun, S, Matsumoto, H, Kojima, H, Murata, T, Fairfield, D H, Lepping, R P, Samson, J C, Rostoker, G, Reeves, G D, Rodger, A L, and Singer, H J. Multipoint study of a substorm on February 9, 1995. United States: N. p., 1998. Web. doi:10.1029/97JA02632.
Lui, A T, Williams, D J, McEntire, R W, Ohtani, S, Zanetti, L J, Bristow, W A, Greenwald, R A, Newell, P T, Christon, S P, Mukai, T, Tsuruda, K, Yamamoto, T, Kokubun, S, Matsumoto, H, Kojima, H, Murata, T, Fairfield, D H, Lepping, R P, Samson, J C, Rostoker, G, Reeves, G D, Rodger, A L, & Singer, H J. Multipoint study of a substorm on February 9, 1995. United States. doi:10.1029/97JA02632.
Lui, A T, Williams, D J, McEntire, R W, Ohtani, S, Zanetti, L J, Bristow, W A, Greenwald, R A, Newell, P T, Christon, S P, Mukai, T, Tsuruda, K, Yamamoto, T, Kokubun, S, Matsumoto, H, Kojima, H, Murata, T, Fairfield, D H, Lepping, R P, Samson, J C, Rostoker, G, Reeves, G D, Rodger, A L, and Singer, H J. Sat . "Multipoint study of a substorm on February 9, 1995". United States. doi:10.1029/97JA02632.
@article{osti_298591,
title = {Multipoint study of a substorm on February 9, 1995},
author = {Lui, A T and Williams, D J and McEntire, R W and Ohtani, S and Zanetti, L J and Bristow, W A and Greenwald, R A and Newell, P T and Christon, S P and Mukai, T and Tsuruda, K and Yamamoto, T and Kokubun, S and Matsumoto, H and Kojima, H and Murata, T and Fairfield, D H and Lepping, R P and Samson, J C and Rostoker, G and Reeves, G D and Rodger, A L and Singer, H J},
abstractNote = {An extended interval of strong northward interplanetary magnetic field (IMF) was observed by the Wind spacecraft located at an upstream distance of {approximately}193 R{sub E} from February 8{endash}10, 1995, with a brief break of southward IMF from 0200 to 0400 UT on February 9. This brief interval of southward IMF led to an isolated substorm of moderate intensity ({approximately}500 nT) with expansion phase starting at {approximately}0431 UT. This substorm may be triggered by the northward turning of the IMF since its onset time matched well with the time expected for the arrival of the northward turning of the IMF at Earth. The substorm activities were monitored by 11 spacecraft in space (Wind, IMP 8, Geotail, six geosynchronous satellites, one DMSP satellite, and Freja) and two networks of ground stations (Canopus and SuperDARN) covering both the northern and southern hemispheres. The extensive coverage of this event provides us with results (1) showing some unusual characteristics possibly related to the isolated nature of the substorm and (2) revealing some surprising features difficult to reconcile with the traditional substorm model. In the first category is unusually long duration of the growth phase and the long time delay between substorm expansion onset and particle injection onset at the geosynchronous orbit. In the second category is new evidence for multiple particle acceleration sites during substorm expansion and for sunward flow during the late expansion phase of a substorm being unrelated to a single acceleration site ({ital X} line) moving from the near-Earth tail to the more distant tail. We also present observations which show the possible optical signature on the ground of bursty bulk flows in the magnetotail. {copyright} 1998 American Geophysical Union},
doi = {10.1029/97JA02632},
journal = {Journal of Geophysical Research},
number = A8,
volume = 103,
place = {United States},
year = {1998},
month = {8}
}