WEAK SUDDEN IMPULSE DETECTED IN MAG DATA 12 08 01 1135UT Mean Mag Parameters Pre/Post Impulse: Pre Post Pre/Post Stn Unit Impulse Impulse Change dwn nT 59.0 73.3 14.3 hbt nT 60.9 73.1 12.3 cbr nT 9.5 25.0 15.5