title: Magnetosphere sawtooth oscillations induced by ionospheric outflow.
abstract: The sawtooth mode of convection of Earth's magnetosphere is a 2- to 4-hour planetary-scale oscillation powered by the solar wind-magnetosphere-ionosphere (SW-M-I) interaction. Using global simulations of geospace, we have shown that ionospheric O(+) outflows can generate sawtooth oscillations. As the outflowing ions fill the inner magnetosphere, their pressure distends the nightside magnetic field. When the outflow fluence exceeds a threshold, magnetic field tension cannot confine the accumulating fluid; an O(+)-rich plasmoid is ejected, and the field dipolarizes. Below the threshold, the magnetosphere undergoes quasi-steady convection. Repetition and the sawtooth period are controlled by the strength of the SW-M-I interaction, which regulates the outflow fluence.
authors.affiliation: Thayer School of Engineering, Dartmouth College, Hanover, NH, USA. ojbrambles@dartmouth.edu
authors.forename: O J
authors.initials: OJ
authors.lastname: Brambles
authors.forename: W
authors.initials: W
authors.lastname: Lotko
authors.forename: B
authors.initials: B
authors.lastname: Zhang
authors.forename: M
authors.initials: M
authors.lastname: Wiltberger
authors.forename: J
authors.initials: J
authors.lastname: Lyon
authors.forename: R J
authors.initials: RJ
authors.lastname: Strangeway