Routine Space Environment Product Issued Weekly
Issued by NWS
FXXX06 KWNP 240526
:Product: 7-day Space Weather Highlights
:Issued: 2015 Aug 24 0441 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# 7-day Space Weather Highlights
Highlights of Solar and Geomagnetic Activity
17 - 23 August 2015
Solar activity ranged from very low to moderate levels. Very low
activity was observed on 17-19 Aug, low level activity on 20 and 23
Aug and moderate level activity on 21-22 Aug. Developing Region 2403
(S15, L=193, class/area Ekc/760 on 23 Aug), which exhibited a
complex beta-gamma-delta magnetic configuration, produced all of the
flare activity during the period.
On 21 Aug, Region 2403 produced three M1 (R1-minor) flares, the
largest was an M1/2b flare observed at 21/0948 UTC. Associated with
this event was a Type II radio emission (estimated 490 km/s shock
velocity) and a partial-halo CME observed off the south limb, first
visible in SOHO/LASCO C2 imagery at 21/1024 UTC. Analysis of this
CME determined that a weak Earth-directed component was present.
22 Aug saw 2 more M-class flares produced by Region 2403, the
largest was an M3/1b flare observed at 22/2124 UTC. Early on the
22nd, the region produced an M1/1b flare observed at 22/0649 UTC.
Associated with this event was a Type II radio emission (estimated
1149 km/s shock velocity), a Type IV radio emission and a
partial-halo CME observed off the NE limb, first visible in
SOHO/LASCO C2 imagery at 22/0712 UTC. Analysis of this CME
determined that a weak Earth-directed component was present.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at
high levels on 17-22 Aug with a peak flux of 9,116 pfu observed at
21/1830 UTC. Moderate levels were observed on 23 Aug.
Geomagnetic field activity generally ranged from quiet to active
levels during the period. Isolated minor storm (G1-minor) periods
were observed midday on 17 Aug and again on 23 Aug. An isolated
major storm (G2-moderate) period was observed between 0600-0900 UTC
on 23 Aug. From 17-20 Aug, field conditions ranged from quiet to
minor storm levels and were influenced by a geoeffective positive
polarity coronal hole high speed stream (CH HSS). During this time
frame, measurements at the ACE satellite indicated peak wind speeds
approaching 600 km/s midday on 17 Aug. However, ACE parameters
indicated a fairly weak magnetic structure was present with Bz
measuring a maximum southward extent of only -7 nT. Quiet to
unsettled conditions were present for 21-22 Aug.
By 23 Aug, field conditions increased to unsettled to major storm
levels under the influence of a co-rotating interaction region (CIR)
in advance of an equatorial, positive polarity CH HSS. At about
23/0600 UTC, solar wind parameters observed an increase in wind
speeds from about 400 km/s to near 550 km/s by about 23/0900 UTC.
Wind speeds further increased to 610 km/s by 23/1400 UTC before
ending the period near 525 km/s. IMF total field registered maximum
readings of 15 nT at about 23/0700 UTC while the Bz component
reached a maximum southward extent of -12 nT at about 23/0600 UTC.
The phi angle remained in a predominately positive (away)
orientation throughout the summary period.