Journal article
Associating ground magnetometer observations with current or voltage generators
Virginia Polytechnic Institute and State University1
Beihang University2
New Jersey Institute of Technology3
RAS - Space Research Institute4
University of Michigan, Ann Arbor5
National Space Institute, Technical University of Denmark6
Geomagnetism, National Space Institute, Technical University of Denmark7
A circuit analogy for magnetosphere-ionosphere current systems has two extremes for driversof ionospheric currents: ionospheric elec tric fields/voltages constant while current/conductivity vary—the“voltage generator”—and current constant while electric field/conductivity vary—the “current generator.”Statistical studies of ground magnetometer observations associated with dayside Transient High LatitudeCurrent Systems (THLCS) driven by similar mechanisms find contradictory results using this paradigm:some studies associate THLCS with voltage generators, others with current generators.
We argue that mostof this contradiction arises from two assumptions used to interpret ground magnetometer observations:(1) measurements made at fixed position relative to the THLCS field-aligned current and (2) negligibleauroral precipitation contributions to ionospheric conductivity. We use observations and simulations toillustrate how these two assumptions substantially alter expectations for magnetic perturbations associatedwith either a current or a voltage generator.
Our results demonstrate that before interpreting groundmagnetometer observations of THLCS in the context of current/voltage generators, the location of a groundmagnetometer station relative to the THLCS field-aligned current and the location of any auroral zoneconductivity enhancements need to be taken into account.
Language: | English |
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Year: | 2017 |
Pages: | 7130-7141 |
ISSN: | 21699402 , 21699380 , 21562202 and 01480227 |
Types: | Journal article |
DOI: | 10.1002/2017JA024140 |
ORCIDs: | 0000-0002-2643-2202 , 0000-0002-3800-2162 , 0000-0003-2795-822X , 0000-0002-1013-6505 , 0000-0003-1264-3612 , 0000-0002-6350-405X , 0000-0003-3056-7465 , 0000-0002-0590-1022 , Behlke, Rico and Naemi Willer, Anna |