:Issued: 2025 Jan 21 1442 UTC :Product: documentation at http://www.sidc.be/products/bul #--------------------------------------------------------------------# # SIDC Weekly bulletin on Solar and Geomagnetic activity # #--------------------------------------------------------------------# WEEK 1255 from 2025 Jan 13 Solar Active Regions (ARs) and flares --------------- Solar flaring activity was low at the beginning of the week, but became moderate to high towards the end of the week. There were a total number of 15 active regions observed on the visible solar disk over the week. A total of 54 C-class flares and 11 M-class flares were observed. The largest flare was a 7.4-flare, peaking on January 17 at 13:35 UTC, which was produced by NOAA Active Region 3964 (beta-gamma). NOAA AR 3964 was the most active and produced almost all of the M-class flares this week. Coronal mass ejections --------------------- During the past week, no CME (Coronal Mass Ejection) with an Earth directed component was observed. Coronal Holes --------------------- During past week, one large east-west elongated negative polarity equatorial Coronal Hole (CH) crossed the central meridian in the southern hemisphere between Jan 13 and Jan 17. Proton flux levels --------------------- The greater than 10 MeV GOES proton flux was below the 10pfu threshold for the entire week. Electron fluxes at GEO --------------------- The greater than 2 MeV electron flux as measured by GOES 16 remained below the 1000 pfu threshold. The 24h electron fluence was at nominal levels. Solar wind --------------------- The solar wind at Earth was mainly slow during the week, except on JAN 17 and beginning of JAN 18 when the solar wind at Earth was under the influence of the high speed stream of the coronal hole. The solar wind ranged between 284 and 610 km/s and the interplanetary magnetic field was between 4 and 11 nT, and with the Bz reaching a minimum value of -10 nT. Geomagnetism --------------------- Geomagnetic conditions were both globally and locally quiet to unsettled, but with some short periods of active conditions (Kp 4) over the week. --------------------------------------------------------------------------- DAILY INDICES DATE RC EISN 10CM Ak BKG M X 2025 Jan 13 /// 085 160 012 C1.2 0 0 2025 Jan 14 /// 077 166 012 C1.4 0 0 2025 Jan 15 /// 084 174 016 C1.5 0 0 2025 Jan 16 /// 127 208 014 C2.0 0 0 2025 Jan 17 /// 152 227 024 C2.4 9 0 2025 Jan 18 /// 151 222 009 C1.7 2 0 2025 Jan 19 /// 142 234 016 C1.5 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 17 0201 0211 0217 ////// M1.3 ///3964 17 0308 0320 0334 ////// M1.1 ///3961 VI/2III/1 17 0910 0919 0923 ////// M2.0 ///3964 17 1119 1137 1149 ////// M1.5 ///3964 17 1324 1335 1339 ////// M7.4 ///3964 CTM/1 17 1842 1850 1904 N08W33 M2.1 SN ///3964 17 1944 1949 1955 N07W32 M1.8 S ///3964 III/1 17 1959 2001 2002 N06W29 M1.1 SF ///3964 17 2200 2205 2214 N08W34 M1.0 1 ///3964 CTM/2III/1 18 0044 0058 0103 N11W32 M1.7 SN ///3964 VI/2 18 0300 0307 0315 N11W32 M1.1 1N ///3964 19 0328 0332 0336 ////// M2.4 ///3964 #--------------------------------------------------------------------# # 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 # #--------------------------------------------------------------------#