:Issued: 2024 Sep 12 0717 UTC :Product: documentation at http://www.sidc.be/products/bul #--------------------------------------------------------------------# # SIDC Weekly bulletin on Solar and Geomagnetic activity # #--------------------------------------------------------------------# WEEK 1236 from 2024 Sep 02 Solar Active Regions (ARs) and flares --------------- Over the past week, solar activity has been at moderate levels, with several C-class and M-class flares observed. The most significant were M5.5 and M5.6 flares from active regions near the east limb at approximately 20 degrees south latitude, peaking at 13:22 and 13:31 UTC on September 4. Other notable flares originated from NOAA AR 3807 and AR 3806, both of which display complex beta-gamma magnetic field configurations. Coronal mass ejections --------------------- Several halo coronal mass ejections (CMEs) were observed in LASCO/C2 coronagraph images over the past week. Due to the location of their source regions, no impact on Earth was expected. However, a more recent CME, detected at 00:36 UTC on September 8, is associated with a filament eruption at 15 degrees North and 23 degrees West. The projected speed is approximately 600 km/s in the northwest direction, and this CME has been identified as potentially Earth-directed. Coronal Holes --------------------- At the beginning of the week, a small negative polarity coronal hole (CH) spanning 30-50 degrees South crossed the central meridian, with its high-speed solar wind stream expected to affect Earth. Additionally, a small positive polarity CH, spanning 25-35 degrees North, began crossing the central meridian on September 2, with its stream expected to influence Earth's solar wind environment. Proton flux levels --------------------- Over the past 24 hours, the greater than 10 MeV GOES proton flux increased but remained below the 10 pfu threshold, likely due to the long-duration M5.5 flare and a halo CME from September 1. Electron fluxes at GEO --------------------- Electron fluxes measured by the GOES-16 satellite (greater than 2 MeV) remained below the 1000 pfu threshold. Solar wind --------------------- At the beginning of the week, Earth has experienced slow solar wind conditions, with speeds ranging between 300 and 495 km/s. The total interplanetary magnetic field (IMF) fluctuated between 5 and 12 nT, and the IMF southward Bz-component varied between -6 and 9 nT. On September 4, a solar wind shock was observed, likely linked to a coronal mass ejection (CME) from September 1, leading to enhanced solar wind conditions. Geomagnetism --------------------- Over the past week, geomagnetic conditions ranged from quiet to unsettled globally and locally (NOAA Kp and K-Dourbes 1-3). Following a solar wind shock on September 4, conditions briefly became active (NOAA Kp and K-Dourbes 4). --------------------------------------------------------------------------- DAILY INDICES DATE RC EISN 10CM Ak BKG M X 2024 Sep 02 271 195 238 008 C4.1 5 0 2024 Sep 03 /// 179 262 005 C3.2 2 0 2024 Sep 04 274 174 262 015 C3.2 6 0 2024 Sep 05 /// 181 241 004 C3.2 6 0 2024 Sep 06 263 189 249 007 C2.4 0 0 2024 Sep 07 /// 167 222 008 C2.7 1 0 2024 Sep 08 /// 173 228 009 C2.0 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 02 0518 0529 0549 ////// M1.9 ///3813 02 1333 1343 1353 ////// M2.9 67/3807 02 1957 2011 2028 ////// M1.4 67/3807 02 2056 2102 2110 ////// M1.8 ///3813 02 2235 2301 2330 ////// M1.5 67/3807 III/2 03 0712 0722 0739 S20E57 M1.4 S 77/3813 III/1 03 1551 1602 1608 ////// M3.3 77/3813 04 0243 0255 0311 S22E49 M1.4 SF 77/3813 04 0449 0456 0505 S17W62 M1.2 SF 67/3807 04 0555 0601 0607 S12W12 M1.0 SF 68/3806 04 0607 0611 0616 S12W12 M1.0 SF 68/3806 04 1308 1321 1327 ////// M1.0 77/3813 04 1941 2000 2016 S13E21 M1.2 1F 75/3811 05 0017 0020 0024 S15W70 M1.0 SF 67/3807 05 0312 0325 0337 ////// M1.1 68/3806 05 0337 0344 0349 ////// M1.0 77/3813 05 0847 0856 0901 S16W72 M2.8 SF 67/3807 05 0926 0942 0952 ////// M1.6 67/3807 05 1320 1325 1335 ////// M1.3 67/3807 07 0617 0749 0917 S27E34 M1.6 1F 82/3815 08 1507 1530 1556 S18W30 M1.5 1N 75/3811 #--------------------------------------------------------------------# # 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 # #--------------------------------------------------------------------#