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 May 01 2033 UTC :Product: documentation at http://www.sidc.be/products/bul #--------------------------------------------------------------------# # SIDC Weekly bulletin on Solar and Geomagnetic activity # #--------------------------------------------------------------------# WEEK 1217 from 2024 Apr 22 Solar Active Regions (ARs) and flares --------------- The solar flaring activity over the past week was predominantly at moderate levels with daily M-class flaring. There were over twenty numbered and several unnumbered active regions on the visible solar disc. The most notable ones in the first half of the week were NOAA AR 3639, NOAA AR 3643, NOAA AR 3645 and NOAA AR 3647, which reached high magnetic complexity with beta-gamma, beta-delta or beta-gamma-delta magnetic type classification. Towards the end of the week NOAA 3654 (beta-gamma) became the largest and most complex region triggering most of the solar flaring activity. The strongest activity was an M3.6 flare, start time 03:06 UTC, end time 03:37 UTC, peak time 03:19 UTC on April 23rd, produced by NOAA AR 3654 (beta). Coronal mass ejections --------------------- There were multiple filament eruptions on disc throughout the week, some related to coronal mass ejections (CMEs) with possible minor Earth-directed component. A slow partial halo CME was observed in the LASCO/C2 coronagraph imagery starting at 18:00 UTC on April 23rd. The CME propagated to the south-west with an estimated projected velocity below 380 km/s. The eruption appeared related to an M2.9 flare, peak time 17:44 UTC on April 23rd, produced by NOAA AR 3638 (beta). An associated type II radio emission was observed starting at 17:10 UTC on April 23rd with estimated velocity of 358 km/s. Analysis of this event suggested no to possibly minor glancing blow impact on Earth late on April 27th. Coronal Holes --------------------- Multiple positive polarity coronal holes and one long and patchy negative polarity coronal hole (stretching from high northern to the equatorial latitudes) have crossed the central meridian throughout the week. 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 GOES 16 was below the 1000 pfu threshold throughout most of the week, except on April 25th. The greater than 2 MeV electron flux as measured by GOES 18 was partially exceeding the 1000 pfu threshold in the period April 21st-April 25th. The electron fluence was at nominal levels throughout the entire week. Solar wind --------------------- The week started with a slightly enhanced solar wind conditions due to a mixed influence of connection to a high speed stream from a negative polarity coronal hole and the waning influence of a mild ICME arrival. Prestine slow solar wind conditions were observed in the middle of the week, followed by a mild ICME arrival on April 26th mixed with the influence of a connection to a high speed stream from a positive polarity coronal hole. The solar wind speed throughout the week was mostly below 500 km/s. The interplanetary magnetic field reached a maximum of 16.85 nT on April 27th with a minimum Bz of -11.6 nT. The interplanetary magnetic field was switching orientation between the negative and the positive sectors. Geomagnetism --------------------- The geomagnetic conditions were at quiet to active levels in the beginning of the week. Mostly quiet conditions were observed in the period of April 22nd throughout April 25th. Isolated minor storm levels were registered late on April 26th, followed by quiet to active conditions throughout the end of the week. --------------------------------------------------------------------------- DAILY INDICES DATE RC EISN 10CM Ak BKG M X 2024 Apr 22 /// 265 227 008 C3.3 7 0 2024 Apr 23 308 266 219 007 C3.0 3 0 2024 Apr 24 /// 251 199 003 C2.6 5 0 2024 Apr 25 /// 209 167 002 C1.6 3 0 2024 Apr 26 /// 141 153 023 C2.0 0 0 2024 Apr 27 /// 139 153 014 C1.8 2 0 2024 Apr 28 /// 119 140 006 C1.3 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 22 0758 0813 0830 S07W36 M1.0 SF 60/3645 VI/2 22 1313 1335 1417 S10W39 M1.6 1N 60/3645 VI/2 22 1446 1455 1508 N23E07 M1.1 1F 60/3645 22 1508 1519 1532 N23E07 M1.6 1F 64/3646 22 1541 1550 1558 S11E67 M2.8 SN ///3656 III/3 22 1626 1630 1636 ////// M1.0 ///3656 III/2 22 2105 2116 2124 S17W48 M1.5 1N 59/3638 VI/1III/3II/3 23 0306 0319 0335 ////// M3.6 ///3654 III/1 23 0807 0821 0829 S05E41 M3.0 1B ///3654 VI/3 23 1733 1744 1752 S08W59 M2.9 SF 59/3638 III/3II/2 24 0013 0029 0038 S20W62 M1.7 SF 59/3638 24 0230 0239 0244 ////// M1.8 59/3638 V/2 24 1207 1214 1239 ////// M1.4 60/3645 24 2227 2250 2254 ////// M1.1 62/3647 III/1VI/1 24 2254 2259 2305 ////// M2.0 59/3638 25 0140 0149 0201 ////// M1.0 60/3645 25 1311 1321 1327 ////// M1.0 59/3638 V/3III/1 25 1703 1712 1716 ////// M1.3 59/3638 III/2 27 1223 1235 1244 S07W15 M2.1 SN 74/3654 CTM/1 27 2129 2140 2149 ////// M3.0 74/3654 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 # #--------------------------------------------------------------------#
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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.