13 February


Solar wind parameters, as observed at the ACE spacecraft, reflected
a return to nominal background conditions. Early in the period, there
were indications that Earth was riding near a solar sector boundary, but
parameters have since leveled off. Solar wind speeds steadily dropped
from beginning speeds near 450 km/s to end the period near 370 km/s. IMF
Bt was steady near 6 nT for most of the period. A slight increase in
speed back up to 400 km/s and an isolated bump in Bt to 9 nT was
observed just before 13/0900 UTC, likely the result of a near miss
transient. Bz began the period with brief deflections as low as -3 nT,
but remained mostly positive from 12/1600 UTC through the end of the
period. Phi angle remained in a negative (towards) orientation for the
entire period.

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