Physics Department Seminar University of Alaska Fairbanks

J O U R N A L    C L U B


Field aligned currents in the Earth’s magnetosphere: general behaviours, inter-hemispheric comparisons, and relation to the auroras

J. A. Carter
University of Leicester



Electrical currents define the shape of, and maintain the stress balance in, all magnetized astrophysical systems. We use data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE), to explore distributions of the field-aligned current (FAC) systems of the Earth’s magnetosphere. These FACs connect the magnetosphere and ionosphere, transmitting stress from the solar wind to drive ionospheric convection against the friction of the atmosphere, produce the auroras, and dissipate energy through heating. The AMPERE dataset, derived from measurements made by magnetometers onboard approximately 70 Iridium telecommunication satellites, covers both hemispheres at 2-minute cadence, from 2010 until the present. This allows us to explore the relationship of the FACs with interplanetary drivers, during substorms, and make comparisons between hemispheres. In addition, we compare distributions of the FACs with auroral emissions, obtained by the Special Sensor Ultraviolet Spectrographic Imagers onboard the later generation U.S. Air Force Defense Meteorological Satellite Program satellites.


Friday, 29 March 2019

Globe Room, Elvey Building