Fig. 2
From: Global and local Joule heating during substorms in St. Patrick’s Day 2015 geomagnetic storm
From top to bottom: components of IMF viz Bx, By and Bz, Btotal, x-component of solar wind velocity (vx), solar wind density (Nsw), temperature variation of electron flux along the IMF direction (T), as observed by WIND spacecraft during 19:00–05:00 UT on 17–18 March 2015. Components of interplanetary magnetic field are plotted in GSM coordinates and the x-component of solar wind velocity is plotted in GSE coordinates. The expansion phase of the substorm, 17–18 March 2015, during 22:58—00:41 UT on 17–18 March 2015 is marked with two vertical lines