SIDC Weekly Bulletin
Review of past solar and geomagnetic activity.| Source | SIDC (RWC-Belgium) |
| Frequency | Weekly |
| Format | Plain text |
| Mail header | SIDC Weekly Bulletin |
| SIDC code | bul |
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:Issued: 2024 Apr 23 0921 UTC :Product: documentation at http://www.sidc.be/products/bul #--------------------------------------------------------------------# # SIDC Weekly bulletin on Solar and Geomagnetic activity # #--------------------------------------------------------------------# WEEK 1216 from 2024 Apr 15 Solar Active Regions (ARs) and flares --------------- The solar flaring activity was mostly at moderate levels over the past week. There were 25 active regions visible throughout the week. 71 C-class flares and 19 M-class flares were recorded, the strongest being an M4.0-flare with peak time 19:32 UTC on Apr 15, associated with NOAA AR 3639. In the first part of the week, most of the flaring activity came from NOAA AR 3634 and NOAA AR 3639. In the second part of the week, most of the flaring activity originated from a group consisted of NOAA AR 3638, 3639, 3643, 3645 and 3647. Coronal mass ejections --------------------- There were multiple coronal mass ejections (CMEs) observed over the course of the week. A faint partial halo coronal mass ejection (CME) was observed in LASCO/C2 coronagraph data from 06:48 UTC on Apr 15. The CME was directed primarily to the North from the Earth's perspective and was likely associated with a small filament eruption near NOAA AR 3636. The CME probably arrived on Apr 19. A small filament eruption occurred in the southeastern quadrant from around 18:36 UTC on Apr 16, the associated CME appeared narrow and slow and was not expected to arrive to Earth. Another filament eruption was observed in the northern quadrant, first seen in SDO/AIA 304 at around 01:16 UTC on Apr 17. An associated CME can be seen in SOHO/LASCO-C2 from 02:36 on Apr 17. The CME is judged to be too narrow to reach Earth. Some more CMEs occurred in coronagraph images afterwards, but all are judged to be too narrow or off the Sun-Earth line to reach Earth. Coronal Holes --------------------- Small negative polarity equatorial coronal hole has began to cross the central meridian on Apr 17. Proton flux levels --------------------- The greater than 10 MeV proton flux was at nominal levels throughout the entire week. Electron fluxes at GEO --------------------- The greater than 2 MeV electron flux, as measured by the GOES-16 satellite, was below the 1000 pfu threshold and the 24h electron fluence was at nominal level over the past week. Solar wind --------------------- The solar wind parameters were indicative of a slow solar wind regime at the beginning of the week. The solar wind conditions became slightly disturbed from around 17:26 UTC on Apr 15, probably registering the arrival of a faint halo CME observed on Apr 12. The magnetic field during the ICME arrivals reached a maximum of 13 nT with a minimum Bz of -11 nT and the solar wind speed remained at slow background values. The next ICME arrival was registered in the solar wind data in the morning of Apr 19, with the shock front arriving around 04:53 UTC on Apr 19. The total magnetic field reached 18 nT, the solar wind speed ranged between 330 km/s and 530 km/s. The southward component of the interplanetary magnetic field fluctuated between -16 nT and 7 nT. This ICME was the expected arrival of the faint partial hallo CME observed on Apr 15. The ICME potentially mixed on its way with an expected high-speed stream from a negative polarity equatorial coronal hole. Geomagnetism --------------------- The geomagnetic activity was at quiet to unsettled levels at the beginning of the week and gradually increased as a result of the ICME arrival, reaching the minor storm level (NOAA-Kp = 5, K-Bel = 5) between 18:00 and 00:00 UTC on Apr 16. The geomagnetic conditions then reduced to quiet to unsettled levels until Apr 19. Geomagnetic conditions reached strong storm levels globally (NOAA-Kp = 7) between 18:00 and 21:00 UTC on Apr 19. Locally over Belgium, only minor geomagnetic storm conditions were observed (K-Bel = 5). The strong storm period was reached due to the prolonged period of negative Bz following second ICME arrival. For the remaining part of the week, geomagnetic conditions were mostly at unsettled to active levels. --------------------------------------------------------------------------- DAILY INDICES DATE RC EISN 10CM Ak BKG M X 2024 Apr 15 /// 164 192 008 C1.5 8 0 2024 Apr 16 /// 181 199 030 C1.6 1 0 2024 Apr 17 251 207 217 006 C1.9 1 0 2024 Apr 18 225 218 227 004 C2.7 4 0 2024 Apr 19 /// 242 213 041 C2.3 2 0 2024 Apr 20 /// 237 /// /// //// 0 0 2024 Apr 21 /// 234 /// /// //// 3 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 15 0106 0118 0126 N34E68 M1.7 SF ///3639 15 0715 0732 0738 N30E57 M1.0 1F ///3639 15 0838 0842 0847 N27W29 M2.3 1B 50/3634 III/2 15 0921 0932 0942 N29E60 M1.2 SF ///3639 VI/2 15 1343 1358 1401 N28E56 M1.1 1F ///3639 III/1 15 1408 1417 1427 N26W33 M2.2 SN ///3639 III/1 15 1401 1404 1406 N26W33 M1.4 SN 50/3634 15 1925 1932 1939 N28E56 M4.0 1N ///3639 16 1749 1802 1814 S10E36 M1.1 2N ///3645 17 2155 2208 2217 S07E22 M1.6 2N 62/3643 18 0232 0248 0253 S11E27 M2.2 SF 59/3638 V/3 18 0717 0737 0809 S12E23 M1.3 SF 62/3643 18 1922 2001 2012 S12E17 M1.6 SF 60/3645 III/1 18 2012 2016 2021 S12E17 M1.6 SF ///3647 III/1 19 0440 0453 0503 N20W58 M2.1 SF 60/3647 VI/1III/1 19 1253 1306 1323 ////// M1.0 60/3647 III/2 21 1239 1259 1334 S06W25 M1.0 1F ///3645 III/2 21 1507 1514 1520 N22E19 M2.2 SF ///3638 V/3III/3 21 2144 2152 2157 S17W37 M3.4 SN ///3638 III/3 #--------------------------------------------------------------------# # 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 # #--------------------------------------------------------------------#
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This report is sent once a week, typically on a monday.The weekly bulletin gives an overview of solar and geomagnetic activity of the past week and includes a noticeable solar events list.
Check the ISES code book for information on ISES codes.