SIDC Weekly Bulletin

:Issued: 2026 Mar 09 1440 UTC
:Product: documentation at http://www.sidc.be/products/bul
#--------------------------------------------------------------------#
# SIDC Weekly bulletin on Solar and Geomagnetic activity             #
#--------------------------------------------------------------------#
WEEK 1314 from 2026 Mar 02

Solar Active Regions (ARs) and flares
---------------
Solar flaring activity has been low throughout the week, with a few C-class
flares. The strongest flare was a C4.5 flare (SIDC Flare 7119), peaking at
04:38 UTC on March 02, associated with SIDC Sunspot Group 805 (NOAA Active
Region 4384). There was a total of 13 numbered active regions on the
visible disk, mostly with magnetic types alpha and beta. SIDC Sunspot Group
801 (NOAA Active Region 4378) briefly developed a beta-delta magnetic type
on March 06. SIDC Sunspot Group 803 (NOAA Active Region 4381) developed to
a beta-gamma magnetic type on March 08.

Coronal mass ejections
---------------------
A few Coronal Mass Ejections (CMEs) were detected during the week, but none
was Earth-directed. A slow Coronal Mass Ejection (SIDC CME 630) was
observed in LASCO/C2 and STEREO-A coronagraph imagery, lifting off from the
north limb around 10:30 UTC on March 02. It is associated with a prominence
eruption near the northeast limb, observed in SUVI 304 data starting from
09:30 UTC. A wide CME (SIDC CME 633) was observed in LASCO/C2 and STEREO-A
coronagraph imagery, lifting off the east limb around 11:00 UTC on March
03. It was most likely a backsided event. A slow, wide Coronal Mass
Ejection (SIDC CME 637) was observed in LASCO/C2 and LASCO/C3 coronagraph
imagery, lifting off the east limb around 20:55 UTC on March 06. The source
region was not very clear, but the CME is likely associated with eruptive
activity near the east limb.

Coronal Holes
---------------------
A total of four coronal holes crossed the central meridian during last
week. The first two were a northern, mid-latitude and a southern,
high-latitude coronal holes (SIDC Coronal Holes 152 and 153 respectively)
both with positive polarity. In the middle of the week, two negative
polarity coronal holes crossed the central meridian: SIDC Coronal Hole 149
(equatorial) and SIDC Coronal Hole 142 (northern, mid-latitude).

Proton flux levels
---------------------
The greater than 10 MeV proton flux was below the 10 pfu threshold
throughout the week.

Electron fluxes at GEO
---------------------
The greater than 2 MeV electron flux as measured by GOES 18 and GOES 19 was
above the 1000 pfu threshold at the beginning of the week, having then
decreased to normal levels since the middle of the week. The 24-hour
electron fluence was at moderate levels until March 04, when it decreased
to normal levels.

Solar wind
---------------------
The solar wind parameters reflected slow solar wind conditions until March
04, when a possible influence from a mild high-speed stream from ither SIDC
Coronal Hole 152 (northern, positive polarity) or SIDC Coronal Hole 153
(southern, positive polarity) was recorded. The solar wind speed increased
to around 450 km/s, returning again to the slow wind regime the following
day. Enhanced solar wind conditions were observed again on March 07-08,
under the influence of high-speed streams from SIDC Coronal Hole 149
(equatorial, negative polarity) and SIDC Coronal Hole 142 (northern,
mid-latitude, negative polarity). Solar wind speed values reached a maximum
of around 680 km/s. The interplanetary magnetic field reached a maximum of
12 nT and the Bz component a minimum of -8 nT.

Geomagnetism
---------------------
Geomagnetic conditions globally were mostly quiet in the beginning of the
week (NOAA Kp 1 to 2). An isolated interval of minor storm levels (NOAA Kp
5) was recorded between 21:00 UTC on March 03 and 00:00 UTC on March 04.
Mostly active levels (Kp 4), with an isolated interval on minor storm
levels (NOAA Kp 5- ) between 00:00 UTC and 03:00 UTC on March 08, were
recorded towards the end of the week. The first geomagnetic storm was due
to a possible mild high-speed stream arrival from SIDC Coronal Holes 152
(northern, positive polarity) or SIDC Coronal Hole 153 (southern, positive
polarity). The second geomagnetic storm was the consequence of high-speed
streams from SIDC Coronal Hole 149 (equatorial, negative polarity) and SIDC
Coronal Hole 142 (northern, mid-latitude, negative polarity).

---------------------------------------------------------------------------
DAILY INDICES
DATE           RC   EISN  10CM   Ak   BKG    M   X
2026 Mar 02   107    081   148   004   B9.0   0   0   
2026 Mar 03   106    086   144   015   B5.8   0   0   
2026 Mar 04   138    068   141   008   B4.4   0   0   
2026 Mar 05   ///    091   146   003   B5.4   0   0   
2026 Mar 06   ///    088   143   009   B5.6   0   0   
2026 Mar 07   ///    082   135   020   B5.0   0   0   
2026 Mar 08   ///    078   135   025   B5.4   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)
---------------------------------------------------------------------------

NOTICEABLE EVENTS SUMMARY
DAY BEGIN MAX  END  LOC    XRAY OP  10CM Catania/NOAA RADIO_BURST_TYPES 
NONE
#--------------------------------------------------------------------#
# Solar Influences Data analysis Center - RWC Belgium                #
# Royal Observatory of Belgium                                       #
#                                                                    #
# Website         http://www.sidc.be.                                #
# E-mail          sidc-support@oma.be                                #
# To unsubscribe  http://www.sidc.be/registration/unsub.php          #
#                                                                    #
# Legal notices:                                                     #
# - Intellectual Property Rights:                                    #
#   http://www.astro.oma.be/common/internet/en/data-policy-en.pdf    #
# - Liability Disclaimer:                                            #
#   http://www.astro.oma.be/common/internet/en/disclaimer-en.pdf     #
# - Use and processing of your personal information:                 #
#   http://www.astro.oma.be/common/internet/en/privacy-policy-en.pdf #
#--------------------------------------------------------------------#