Fig. 3From: Inverting magnetic meridian data using nonlinear optimizationCurrent over Russian chain from 18.5 to 19.5 UT April 1, 1986 (bottom). Borders of electrojet over Russian chain, second from bottom. OMNI IMF Bz (second from top). Standard AL index (top). Substorm onset took place before Bz northward turning and before AL indicated itBack to article page