Extreme Space Weather
The cloud has arrived
posted: Feb 18, 2011 - 06:00UT - 07:00LT
The plasma cloud has arrived, February 18, just after midnight. The solar wind speed jumped from 350 km/s to 500 km/s as was foreseen. The magnetic field is strong: between 30 and 40 nT but not opposite to the magnetic field of the Earth. We have only active conditions.
This might change as soon as the Bz component of the magnetic field rotates to negative values. In this case, the conditions can become stormy.
The satellite ACE at the L1 point in front of the Earth saw the first signal of a magnetic plasma cloud. The magnetic data and the speed jumped to higher values.