Premium
Continent‐Wide R1/R2 Current System and Ohmic Losses by Broad Dipolarization‐Injection Fronts
Author(s) -
Panov E. V.,
Baumjohann W.,
Nakamura R.,
Weygand J. M.,
Giles B. L.,
Russell C. T.,
Reeves G.,
Kubyshkina M. V.
Publication year - 2019
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2019ja026521
Subject(s) - substorm , geophysics , geostationary orbit , ionosphere , physics , joule heating , geosynchronous orbit , current (fluid) , geology , ohmic contact , atmospheric sciences , magnetosphere , satellite , magnetic field , astronomy , quantum mechanics , thermodynamics , electrode
We employ Magnetospheric Multiscale, Geostationary Operational Environmental and Los Alamos National Laboratory satellites, as well as the ground magnetometer networks over Greenland and North America to study a substorm on 9 August 2016 between 9 and 10 UT. We found that during the substorm two earthward flows, whose dipolarization‐injection fronts exceeded 6.5 and 4 Earth's radii ( R E ) in Y GSM , impinged and rebounded from Earth's dipolar field lines at L =6–7 downtail, where L is the McIlwain number. The impingements and rebounds ended with a substorm current system of downward R1 and upward R2 currents which grew to azimuthally cover the whole North American continent. At the fronts, regions of enhanced negative j·E ′ were formed and peaked toward the end of the impingements. These regions appeared to be conjugate with eastward moving aurora (along the growth phase arc and together with eastward drifting energetic electrons at geosynchronous equatorial orbit), which manifests ionospheric Ohmic losses.