Solar wind summary (Last 24 hours)

21 March


Solar wind parameters, as measured by the ACE spacecraft, reflected
predominately nominal conditions for the period. Wind speed values
averaged near 340 km/s. Total field values rose to near 10 nT multiple
times, but intermittently. The Bz component decreased to near -5 nT for
an extended period between 21/0100 and 21/0900 UTC. The phi angle was in
a predominately negative (toward) orientation.

20 March


Solar wind parameters, as measured by the ACE spacecraft, reflected
nominal conditions for the period. Wind speed values averaged
approximately 350 km/s. Total field values increased from an average of
+5nT briefly to near +10 nT, however the he Bz component was mostly
northward over the period. The phi angle was oriented in a predominately
negative (toward) solar sector.

19 March


Solar wind parameters, as measured by the ACE spacecraft, reflect
nominal conditions over the period. Speed values on average remained
less than 350 km/s and Bt values were at or less than 5nT. Bz remained
predominately positive over the period.

18 March


Solar winds at NASA ACE indicated a slight disturbance with solar wind
speeds increasing from around 300 km/s to 330 km/s at around 18/0600 UTC
with associated fluctuations in temperature and density along with a
solar sector boundary crossing from a positive phi angle measurement to
negative just prior.

17 March


Solar wind speed at the ACE spacecraft generally declined over the past
24 hours, beginning the period near 360 km/s with speeds approaching 300
km/s by period’s end. Phi was predominantly positive (away) with brief
intervals of negative (towards) orientation between 17/0530 – 1000 UTC.
The Bz component was mostly positive to +2 nT with a brief negative
period between 17/0809-1007 UTC, but never dipped below -2 nT. Bt ranged
between 1 to 3 nT.

16 March


Solar wind speed at the ACE spacecraft, reached a peak of 423 km/s at
15/1232 UTC and slowly declined to end-of-period speeds approaching 350
km/s. Total IMF remained below 5 nT. The maximum southward component of
Bz reached -2 nT at 15/1832 UTC. Phi angle was in a predominately
positive (away) sector throughout the period.

15 March


Solar wind speed at ACE began the period at about 450 km/s and gradually
declined to end-of-period speeds near 390 km/s. Phi was in a positive
(away) orientation through about 15/0500 UTC when a switch to a more
negative (towards) orientation occurred. Bz varied from -4 to +5 nT
early in the period. After 14/2000 UTC, Bz did not vary much beyond +/-
2 nT. Bt reached a maximum of 9 nT early in the period and remained
steady at about 5 nT for a majority of the time.

14 March


Solar wind speed measured at the ACE spacecraft observed a steady
increase in speed from early observations near 350 km/s to end-of-period
speeds approaching 500 km/s. A brief interval from about 14/0500 – 0620
UTC observed speeds in the 525 – 625 km/s range. Bt generally ranged
between 6 – 10 nT with periods of 1 – 5 nT observed from 13/2000 – 2400
UTC. IMF Bz varied between -5 to +9 nT through about 13/2000 UTC where
it remained mostly north to +5 nT through the remainder of the period.
The Phi angle varied between positive (away) and negative (towards)
through about 14/0130 UTC when it settled into a positive orientation
for the balance of the period.

13 March


Solar wind parameters, as measured by the ACE spacecraft, continued to
reflect background conditions. Wind speeds ranged between 250 and 335
km/s. Total IMF (Bt) was steady between +4 to +6 nT during the first
half of the period but showed a slight increase at approximately 12/2000
UTC to +9 nT. The Bz component of the IMF reached a maximum southward
extent of -8 nT at 12/2029 UTC. The phi angle was oriented in a negative
(toward) solar sector during the period.

12 March


Solar wind parameters, as measured by the ACE spacecraft, continued to
reflect background conditions. Wind speeds averaged near 310 km/s for
the first half of the period, then began steadily decreasing, ending the
period under 280 km/s. Total IMF (Bt) ranged between 3 and 6 nT, while
the Bz component of the IMF ranged between +/-4 nT. The phi angle began
the period in a positive (away) orientation, but quickly rotated into a
negative (toward) solar sector, where it remained for the rest of the
period.