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Title: Contribution of storm time substorms to the prompt electric field disturbances in the equatorial ionosphere

This study tries to bring out the fact that storm time substorms can compete and at times significantly contribute to the geomagnetically disturbed time prompt penetration electric field effects on low and equatorial latitudes. Observations of unusual equatorial plasma drift data from Jicamarca Unattended Long-term Investigations of the Ionosphere and Atmosphere during two space weather events show that substorms can induce both eastward and westward penetration electric fields under steady southward interplanetary magnetic field (IMF B z) conditions. During the first event on 2 January 2005, the enhancement of the daytime eastward electric field over Jicamarca due to substorm is found to be comparable with the Sq and interplanetary electric field (IEFy) generated electric fields combined. During the second event on 19 August 2006, the substorm is seen to weaken the daytime eastward field thereby inducing a westward field in spite of the absence of northward turning of IMF B z (overshielding). The westward electric field perturbation in the absence of any overshielding events is observationally sparse and contrary to the earlier results. Further, the substorm-induced field is found to be strong enough to compete or almost nullify the effects of storm time IEFy fields. This study also shows quantitativelymore » that at times substorm contribution to the disturbed time prompt electric fields can be significant and thus should be taken into consideration in evaluating penetration events over low latitudes.« less
ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [2] ; ORCiD logo [3] ; ORCiD logo [4]
  1. Physical Research Lab., Ahmedabad (India)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); New Mexico Consortium, Los Alamos, NM (United States)
  3. Kyushu Univ. (Japan)
  4. Nagoya Univ. (Japan)
Publication Date:
Report Number(s):
Journal ID: ISSN 2169-9380; TRN: US1703015
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research. Space Physics
Additional Journal Information:
Journal Volume: 122; Journal Issue: 5; Journal ID: ISSN 2169-9380
American Geophysical Union
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
National Aeronautic and Space Administration (NASA); USDOE
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; Heliospheric and Magnetospheric Physics
OSTI Identifier: