Swarm Observations of Field Aligned Currents during Geomagnetic Storms

Monday, 14 December 2015: 09:00
2018 (Moscone West)
Guan Le1, Hermann Luhr2, Brian J Anderson3, Robert J Strangeway4, Christopher T Russell5, James A Slavin6, Kenneth R Bromund1, Ferdinand Plaschke7, Werner Magnes8, David Fischer7, Rumi Nakamura7, Hannes Karl Leinweber9, Roy B Torbert10, Olivier Le Contel11, Denny M. Oliveira1, Joachim Raeder10 and Larry Kepko1, (1)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (2)Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany, (3)Johns Hopkins University, Baltimore, MD, United States, (4)University of California Los Angeles, Los Angeles, CA, United States, (5)University of California Los Angeles, IGPP/EPSS, Los Angeles, CA, United States, (6)University of Michigan Ann Arbor, Ann Arbor, MI, United States, (7)IWF Institute for Space Research, Graz, Austria, (8)Space Research Institute, Austrian Academy of Sciences, Graz, Austria, (9)Institute of Geophysics and Planetary Physics Los Angeles, Los Angeles, CA, United States, (10)University of New Hampshire Main Campus, Durham, NH, United States, (11)Laboratoire de Physique des Plasmas (UMR7648), CNRS/Ecole Polytechnique/UPMC/Univ. Paris Sud/Obs. de Paris, Paris, France
Field-aligned currents connect the Earth’s magnetosphere to the high latitude ionosphere, and provide a main channel for energy transfer from the magnetosphere to the ionosphere. They are driven by solar wind-magnetosphere interactions and respond dynamically to changes in the solar wind and interplanetary magnetic field. Enhanced interaction during geomagnetic storms significantly intensifies their strength and variability. In this paper, we review our recent observations of field-aligned currents (FACs) during geomagnetic storms using observations from polar orbiting Swarm constellation as well as the Active Magnetosphere and Polar Electrodynamics Response Experiment (AMPERE). Both temporal resolutions and spatial coverage of these observations provide new insights in understanding the FACs and the magnetosphere-ionosphere coupling. We will discuss their spatial and temporal evolutions, ionospheric closure currents, and hemispheric asymmetry during storms.