: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 # #--------------------------------------------------------------------#