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Here is this week's space weather and geophysical report, issued 2015 Sep 14 0537 UTC.
Highlights of Solar and Geomagnetic Activity
07 - 13 September 2015
Solar activity was very low with the exception of 11 September when
Region 2414 (S10, L=321, class/area Dai/190 on 13 Sep) produced an
isolated C1/Sf flare at 11/2137 UTC. A large filament structure was
observed lifting off the NW quadrant in SDO/AIA 171 imagery
beginning at 07/0740 UTC. Subsequent analysis indicated a glancing
blow on 11 September. By 13 September, old Region 2403 (S15, L=192),
which was responsible for multiple M-class flares last rotation,
returned to the visible disk as new Region 2418 (S15, L=203,
class/area Hsx/120 on 13 Sep). The region appears to have
simplified, however due to limb proximity, there might be more
associated spots yet to become visible.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at
mostly high levels with moderate levels observed on 08 September.
The largest flux value for the period was 11,910 pfu observed at
13/1425 UTC.
Geomagnetic field activity was at quiet to severe storm (G3-Strong)
levels during the period. The period began under the influence of a
positive polarity coronal hole high speed stream (CH HSS) coupled
with a coronal mass ejection (CME) that was the result of a filament
eruption on 04 September. Solar wind speed increased to over 600
km/s just after 07/1400 UTC followed by an increase in total field
to 20 nT by 08/0700 UTC. The Bz component rotated southward by
08/2323 UTC to a maximum of -9 nT on 09 September. The geomagnetic
field responded with periods of major storm levels (G2-Moderate)
from 07-09 September. By 10 September, total field had decreased to
5 nT with solar wind speeds around 410 km/s. The geomagnetic field
was at quiet to active levels on 10 September. By early on 11
September, total field increased again to 16 nT while the Bz
component reached a maximum southward deflection of -16 nT at
11/0730 UTC. Solar wind speed increased to near 660 km/s by 11/1140
UTC as a positive polarity coronal hole high speed stream became
geoeffective, possibly in combination with the glancing blow from
the 07 September CME. The geomagnetic field responded with unsettled
to severe storm levels (G3-Strong) on 11 September. Throughout the
rest of the period, solar wind parameters slowly diminished to near
nominal levels. Quiet to active levels were observed on 12 September
with quiet to unsettled levels on 13 September.
Forecast of Solar and Geomagnetic Activity
14 September - 10 October 2015
Solar activity is expected to be at very low to low levels with a
slight chance for M-class flares from 14-26 September as Regions
2414 and 2418 rotate across the visible disk.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at normal to moderate levels with high levels
expected on 14-18, 21-22, 26-27 September and from 02-06, 09-10
October due to influence from multiple recurrent CH HSSs.
Geomagnetic field activity is expected to be at unsettled to active
levels on 14-16, 20, 24-25 September, and from 30 September through
10 October with minor storm (G1-Minor) periods likely on 15
September, 01 October, 05-06 October, 08 October, and major storm
periods possible on 04 October due to recurrent CH HSS activity.
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![Weekly Propagation Summary - 2015 Sep 14 16:10 UTC]()
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