SIDC Weekly Bulletin

Review of past solar and geomagnetic activity.
Source SIDC (RWC-Belgium)
Frequency Weekly
Format Plain text
Mail header SIDC Weekly Bulletin
SIDC code bul


Latest issue

:Issued: 2022 Aug 09 1402 UTC
:Product: documentation at
# SIDC Weekly bulletin on Solar and Geomagnetic activity             #
WEEK 1127 from 2022 Aug 01
Over the past week the solar activity was at very to low levels with 11
C-class flares and no M- or higher class flaring. There were in total ten
active regions on the visible solar disc, namely NOAA 6062 and NOAA 6068 -
NOAA 3076, the majority of which were simple and inactive. The strongest
registered activity throughout the week was a C9.3-class flare from behind
the north-east limb with peak time 23:09 UTC on July 31st. The rest of the
week registered unremarkable sporadic C-class flaring, mainly from NOAA AR
3068, which was the largest and most complex active region throughout the
week, reaching magnetic type beta-gamma. Regardless of its increased
complexity this sunspot group produced only a few low C-class flares. 

Multiple filament and a prominence eruptions were observed throughout the
week, and three type II radio bursts were detected. Nevertheless none of
these events resulted in an Earth-directed coronal mass ejection (CME).

The greater than 10 MeV proton flux was at nominal levels throughout the
entire week and the greater than 2 MeV electron flux only briefly crossed
the 1000 pfu threshold in the UTC afternoon of July 31st and remained well
under the threshold for the rest of the week. The electron fluence was at
nominal levels throughout the entire week.
The week started with slightly elevated solar wind velocity under the mild
influence of a high speed stream (HSS) from a negative polarity coronal
hole. These enhancements continued throughout Aug 4th with maximum solar
wind speed up to 560 km/s. The solar wind conditions returned to mostly
background levels on Aug 5th and Aug 6th until the arrival of another HSS
from a positive polarity coronal hole with a sector boundary crossing
around midnight UT on Aug 7th. The magnitude of the interplanetary magnetic
field reached 15 nT with a minimum recorded Bz component of -13 nT in the
afternoon of Aug 7th while the solar wind speed remained below 450 km/s by
the end of the forecasting week.

The geomagnetic conditions throughout the entire week were mostly quiet to
unsettled. Some active periods were observed in the beginning and towards
the end of the forecasting week due to the two high speed stream arrivals.
DATE           RC   EISN  10CM   Ak   BKG    M   X
2022 Aug 01   020    028   095   011   B2.0   0   0   
2022 Aug 02   040    036   098   012   B2.8   0   0   
2022 Aug 03   042    039   100   012   B2.4   0   0   
2022 Aug 04   051    048   109   ///   B3.5   0   0   
2022 Aug 05   081    077   114   ///   B4.0   0   0   
2022 Aug 06   ///    078   116   ///   B4.5   0   0   
2022 Aug 07   ///    091   116   ///   B4.5   0   0   
# RC   : Sunspot index (Wolf Number) from Catania Observatory (Italy)
# EISN : Estimated International Sunspot Number
# 10cm : 10.7 cm  radioflux (DRAO, Canada)
# Ak   : Ak Index Wingst (Germany)
# BKG  : Background GOES X-ray level (NOAA, USA)
# M,X  : Number of X-ray flares in M and X class, see below (NOAA, USA)

# Solar Influences Data analysis Center - RWC Belgium                #
# Royal Observatory of Belgium                                       #
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This report is sent once a week, typically on a monday.
The weekly bulletin gives an overview of solar and geomagnetic activity of the past week and includes a noticeable solar events list.
Check the ISES code book for information on ISES codes.