title: Space weather. Ionospheric control of magnetotail reconnection.
abstract: Observed distributions of high-speed plasma flows at distances of 10 to 30 Earth radii (R(E)) in Earth's magnetotail neutral sheet are highly skewed toward the premidnight sector. The flows are a product of the magnetic reconnection process that converts magnetic energy stored in the magnetotail into plasma kinetic and thermal energy. We show, using global numerical simulations, that the electrodynamic interaction between Earth's magnetosphere and ionosphere produces an asymmetry consistent with observed distributions in nightside reconnection and plasmasheet flows and in accompanying ionospheric convection. The primary causal agent is the meridional gradient in the ionospheric Hall conductance which, through the Cowling effect, regulates the distribution of electrical currents flowing within and between the ionosphere and magnetotail.
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH, USA. Research Affiliate, High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO, USA. wlotko@dartmouth.edu.
authors.forename: William
authors.initials: W
authors.lastname: Lotko
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.
authors.forename: Ryan H
authors.initials: RH
authors.lastname: Smith
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.
authors.forename: Binzheng
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH, USA. Department of Computer and Information Systems, Vermont Technical College, Randolph Center, VT, USA.
authors.forename: Jeremy E
authors.initials: JE
authors.lastname: Ouellette
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH, USA.
authors.forename: Oliver J
authors.initials: OJ
authors.lastname: Brambles
authors.affiliation: Department of Physics and Astronomy, Dartmouth College, Hanover, NH, USA.
authors.forename: John G
authors.initials: JG
authors.lastname: Lyon