WIND observed a rapid northward IMF rotation at 20:47 UT, and IMP 8 detected this event 35-min later at 21:22 UT. The IMF data are shown in Figure 2, where the WIND data (solid lines) are shifted forward by 35 minutes. At both satellites, the IMF suddenly increased from a few nT to 10 nT without any significant change in the IMF magnitude. The solar wind speed is about 430 km s and the distance between these two spacecraft along the x-axis is 98 , suggesting a 24-min time delay. The observed delay is obtained if the discontinuity is tilted +45 in the xy plane.
© 1998 AGU