15 December

Solar wind parameters were indicative of waning negative polarity
coronal hole high speed stream (CH HSS) influence and the weak passage
of a pair of CMEs from 12 Dec. Solar wind speed values began the period
steady at around 400 km/s but began to increase after 14/1400 UTC with
the likely arrival of the first of the 12 Dec CMEs. Wind speed values
underwent another minor enhancement at 14/1830 UTC, likely with the
arrival of the second of the 12 Dec CMEs, and reached a peak near 600
km/s at around 14/2000 UTC. After 15/0130 UTC, wind speeds began to
slowly decrease and ended the period near 470 km/s. The total field
strength values ranged from 5 nT to 10 nT while the Bz component ranged
from +10 nT to -8 nT.

Leave a Reply