Location
Yosemite National Park
Start Date
2-13-2014 5:00 PM
End Date
2-13-2014 5:30 PM
Description
The magnetospheres of the giant outer planets Jupiter and Saturn are characterized by strong intrinsic magnetic fields, atmospherically driven corotation and plasma sources located within the magnetospheres. Compared to the Earth both planets rotate rapidly (~10 hours at Jupiter and ~11 hours at Saturn) and flows within the magnetosphere are driven toward corotation by coupling between the magnetosphere and the ionosphere. Field aligned currents driven by the atmosphere transmit stresses to the magnetosphere. In the magnetospheres the field aligned currents are closed by radial equatorial currents such that the resulting J×B force is in the direction to drive the magnetospheric plasma toward coronation. Rotational flows extend to the dayside magnetopause. In addition the magnetospheric plasma is dominated by heavy ions whose ultimate source is the volcanic moon Io at Jupiter and ice geysers on the moon Enceledus at Saturn. In this talk we will present results from a series of magnetohydrodynamic simulations of the solar wind magnetosphere and ionosphere systems at Jupiter and Saturn. Emphasis in the presentation will be on the current systems in the outer planet magnetospheres and their coupling to the ionosphere. Reconnection within the outer planets’ magnetospheres can occur internally (Vasyliunas cycle) or driven by reconnection at the dayside magnetopause (Dungey cycle). We will examine the resulting current systems and closure in the ionosphere. In addition at Saturn we will consider the effects of Kelvin-Helmholz waves at the magnetopause and the corresponding currents into the ionosphere.
Simulation Studies of Magnetosphere Ionosphere Coupling in Outer Planet Magnetospheres
Yosemite National Park
The magnetospheres of the giant outer planets Jupiter and Saturn are characterized by strong intrinsic magnetic fields, atmospherically driven corotation and plasma sources located within the magnetospheres. Compared to the Earth both planets rotate rapidly (~10 hours at Jupiter and ~11 hours at Saturn) and flows within the magnetosphere are driven toward corotation by coupling between the magnetosphere and the ionosphere. Field aligned currents driven by the atmosphere transmit stresses to the magnetosphere. In the magnetospheres the field aligned currents are closed by radial equatorial currents such that the resulting J×B force is in the direction to drive the magnetospheric plasma toward coronation. Rotational flows extend to the dayside magnetopause. In addition the magnetospheric plasma is dominated by heavy ions whose ultimate source is the volcanic moon Io at Jupiter and ice geysers on the moon Enceledus at Saturn. In this talk we will present results from a series of magnetohydrodynamic simulations of the solar wind magnetosphere and ionosphere systems at Jupiter and Saturn. Emphasis in the presentation will be on the current systems in the outer planet magnetospheres and their coupling to the ionosphere. Reconnection within the outer planets’ magnetospheres can occur internally (Vasyliunas cycle) or driven by reconnection at the dayside magnetopause (Dungey cycle). We will examine the resulting current systems and closure in the ionosphere. In addition at Saturn we will consider the effects of Kelvin-Helmholz waves at the magnetopause and the corresponding currents into the ionosphere.