Aurora P. A. Delamere Laboratory for Atmospheric and Space Physics Images by John Russell.
Download ReportTranscript Aurora P. A. Delamere Laboratory for Atmospheric and Space Physics Images by John Russell.
Aurora P. A. Delamere Laboratory for Atmospheric and Space Physics Images by John Russell John Russell John Russell John Russell John Russell John Russell John Russell John Russell John Russell John Russell John Russell John Russell John Russell John Russell Dynamics Explorer 1 satellite Noon Dawn Dusk Midnight Solar Storms, Coronal Mass Ejection Solar Wind vsw ~ 400 km/s • Electron energy 1-10 keV; ~0.1 c • Acceleration process? Charged particle motion in Earth’s magnetosphere • The combined effects of the Earth’s magnetic field will result in three characteristic types of motion. Gyro: ~ millisecond Bounce: ~ 0.1-1.0 s Drift: ~ 1-10 minutes The magnetopause controls the transport of • mass • momentum • energy • magnetic flux into the magnetosphere Magnetic Reconnection Open vs. closed configurations of the magnetosphere Magnetic reconnection Closed Open Reconnection Geometry 3D! Ionospheric convection: Open Magnetosphere Ruohoniemi and Baker, 1998 “Dungey cycle” Dungey, 1961 Ionospheric convection: Closed Magnetosphere Foerster et al., 1998 Axford and Hines, [1961] Magnetospheric convection (southward IMF) Substorms • Storage and release of energy in the magnetosphere • Growth phase (energy accumulated in the magnetotail; southward IMF) • Expansion phase (energy released; auroral activity expands poleward and westward; 30-60 minutes) • Recovery phase (magnetosphere returns to original state; 1 to 2 hours; patchy aurora and quiet arcs) Theta Aurora (northward IMF) DE 1 satellite