Solar wind summary (Last 24 hours)

5th January 2016

.24 hr Summary…
Solar wind parameters, as measured by the ACE spacecraft, reflected
mostly nominal conditions for the majority of the day with a minor
enhancement towards the end of the period. Total magnetic field strength
(Bt) was around 5-8 nT for most of the period. After 05/0800 UTC there
was a gradual increase to a peak of 11 nT. The Bz component of the
magnetic field was predominantly northward. Wind speeds underwent a
decline with winds beginning the period around 450 km/s and trending
downward to around 370 km/s before increasing to above 420 km/s by the
period’s end. Phi angle was oriented in the positive sector (away from
the Sun).

.Forecast…
Solar wind parameters are expected to remain near background levels on
day one (05 Jan) under a mostly nominal solar wind regime. A solar wind
enhancement is expected on day two (06 Jan) due to the onset of a
co-rotating interaction region (CIR) followed by the influence of a
positive polarity CH HSS. Wind speeds in excess of 650 km/s were
observed from this HSS last rotation. On day three (07 Jan), CH HSS
effects are expected to persist.

3rd January 2016

.24 hr Summary…
Solar wind parameters were nominal. Solar wind speeds were relatively
steady between 425-500 km/s. Total field strength values varied between
6-9 nT and Bz was mostly northward throughout the period. The phi angle
remained steady in a positive (away) solar sector orientation.

.Forecast…
Solar wind parameters are expected to become enhanced mid-to-late on day
one (03 Jan) with the anticipated arrival of the 01 Jan CME. Solar wind
measurements are expected to begin a return to near-background levels
early on day two (04 Jan) as CME effects subside.

11th November 2015

Solar wind and interplanetary magnetic field (IMF) parameters, as
measured by the ACE spacecraft, reflected the continued influence of a
positive polarity coronal hole high speed stream (CH HSS). Solar wind
velocity remained elevated through the period, with speeds ranging from
about 550 – 750 km/s. Total magnetic field strength continued to decline
from a high of 7 nT, down to about 3 to 5 nT. The phi angle was
predominantly positive (away) with a few short-spanned oscillations into
the negative (towards) sector.

5th November 2015

Solar wind parameters, as measured by the ACE spacecraft, reflected
waning CH HSS effects. Solar wind speeds exhibited a slow, but steady
decrease from just over 700 km/s near the beginning of the period, to
near 540 km/s by the end of the period. Total magnetic field began at 9
nT, but gradually decreased to 5 nT by the end of the period. The Bz
component varied between 8 nT and -5 nT. The phi angle began the period
oscillating between positive and negative sectors before becoming mostly
positive (away) after 04/1400 UTC.

1st January

Solar wind parameters continued under the influence of a negative
polarity coronal hole high speed stream (CH HSS). Solar wind speeds
ranged from 435 km/s to 631 km/s. Total field was between 2 nT and 7 nT
while the Bz component varied between -6 nT and +4 nT. Phi angle was
predominantly negative (towards) with minor deflections into a positive
(away) sector.

31st December

Solar wind speed at the ACE spacecraft decreased from 675 km/s to near
500 km/s over the period. Bt ranged from 1 nT to 5 nT while Bz was
variable and dipped as low as -5 nT. Phi angle was predominately
negative with a few short periods in a positive sector. These
observations suggest the waning of a high speed solar wind stream from
the southern crown coronal hole.

30th December

Solar wind speed at the ACE spacecraft increased over the period from
around 430 km/s to near 755 km/s over the period. Bt reached a maximum
of 15 nT while Bz dipped as low as -10 nT. Bt began to decrease and Bz
became more neutral toward the end of the period. These observations
suggest the presence of a high speed solar wind stream.

20th December

Solar wind parameters continued at nominal levels through the period.
There are currently no signs of the impending arrival of the 17 Dec CME
as of the time of this report. Solar wind speeds ranged from 323 km/s
to 413 km/s with the total field relatively steady near 6 nT. The Bz
component was variable between +/- 6 nT, while the phi angle was
oriented in a positive (away) sector.

12th December

Solar wind parameters indicated the arrival of a solar sector boundary
crossing (SSBC) followed by the onset of a positive polarity coronal
hole high speed stream (CH HSS). Solar wind speeds began the period
near 400 km/s with total field measurements around 5 nT. Density was
increasing through the first half of the period to near 20 p/cc. At
approximately 11/2227 UTC, phi angle switched into a positive (away)
sector, followed by a drop in density and an increase in total field,
temperature, and solar wind speed. Total field reached a maximum of 11
nT at 12/0122 UTC and remained enhanced through the end of the period.
The Bz component reached a maximum of -10 nT at 12/1040 UTC. Solar wind
speed continued to increase with end of period values near 500 km/s.

10th December

The southern pole coronal hole high speed stream (CH HSS) remained
geoeffective although it was beginning to show signs of decay. Solar
wind speed at the ACE spacecraft began the period in the low 500 km/s
range and ended near 450 km/s. Phi began the period in the negative
sector, but was variable after 09/1800 UTC. Bt reached 8 nT while Bz
dipped to -5 nT.