:Issued: 2026 Mar 19 0814 UTC :Product: documentation at http://www.sidc.be/products/bul #--------------------------------------------------------------------# # SIDC Weekly bulletin on Solar and Geomagnetic activity # #--------------------------------------------------------------------# WEEK 1315 from 2026 Mar 09 Solar Active Regions (ARs) and flares --------------- Solar flaring activity has been low to moderate, with a few M-class flares. The strongest flare was a M1.2 flare (SIDC Flare 7174) peaking on March 13 at 09:55 UTC, which was produced by SIDC Sunspot Group 805 (NOAA Active Region 4384). There was a total of 15 numbered active regions on the visible disk, all with simple magnetic types alpha and beta. Coronal mass ejections --------------------- There were no Earth directed Coronal Mass Ejections (CMEs) observed this week. The Coronal Mass Ejection (CME) first detected in SOHO/LASCO-C2 data on 00:48 UTC March 13, associated with a filament eruption, was mainly directed southwards, and passed south of Earth. Coronal Holes --------------------- The large positive polarity trans equatorial coronal hole (SIDC Coronal Hole 154) has been crossing the central meridian since the 11th March, first with a equatorial component, later with midlatitude extensions. Proton flux levels --------------------- The greater than 10 MeV proton flux was below the 10 pfu threshold. Electron fluxes at GEO --------------------- The greater than 2 MeV electron flux as measured by GOES 18 and GOES 19 was fluctuating around the 1000 pfu threshold during the week. The 24-hour electron fluence was fluctuating between normal and moderate levels. Solar wind --------------------- The solar wind conditions have been enhanced almost the entire week. In the beginning of the week, due to the waning influence of the High Speed stream of Coronal Hole 142 (negative polarity), and since 13 March following the HSS of SIDC Coronal Hole 154 (positive polarity). Solar wind speed reach up to 750km/s, the magnetic field reached 13nT with the Bz reaching a maximum of -10nT. Geomagnetism --------------------- Geomagnetic conditions became minor storm since March 13 12:00 UTC and reach moderate storm levels (Kp6) between 03:00 UTC and 06:00UTC on March 14, then mainly active to minor storm conditions were observed. --------------------------------------------------------------------------- DAILY INDICES DATE RC EISN 10CM Ak BKG M X 2026 Mar 09 125 085 128 008 B5.3 0 0 2026 Mar 10 /// 083 127 016 B4.7 0 0 2026 Mar 11 125 115 123 010 B5.5 0 0 2026 Mar 12 114 106 121 010 B5.5 0 0 2026 Mar 13 125 083 112 019 B5.6 1 0 2026 Mar 14 /// 064 112 036 B5.6 0 0 2026 Mar 15 /// 071 109 019 B4.1 1 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 13 0940 0955 1005 N11W67 M1.2 SF 42/4384 II/2 15 0921 0939 0952 S16E33 M1.0 SF 54/4392 III/2 #--------------------------------------------------------------------# # 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 # #--------------------------------------------------------------------#