25 CYCLE OF SOLAR ACTIVITY, THE BRANCH OF RISE: THE PHASE OF MAXIMUM Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 18 - 24.12.2023 Forecast on 25.12.2023 - 01.01.2024 Carrington Rotations 2278-2279 (24.62.11-21.12.2023) Earth out of ecliptic (-1.2 - -2 deg) (S30 - N30 is zone of geoefficiency) THE SUNSPOT-FORMING SOLAR ACTIVITY WAS ON MODERATE LEVELS. ES- TIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD IS W = 090+14/-15 (Wn=135+22/-22). ON THE VISIBLE SOLAR DISC OBSERVED UP 16 SUN- SPOT GROUPS AND UP 7 LOCALIZED ON THE SOUTH HEMISPHERE. NEXT WEEK THE SUNSPOT ACTIVITY EXPECTED ON THE MODERATE LEVELS. WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTER- NATIONAL SYSTEM FOR NEXT WEEK WILL W=100+40/-40. FLARE ACTIVITY WERE ON MIDDLE AND LOW LEVELS. 5 FLARE OF X-RAY CLASS M , 99 -CLASS C, 4 SOLAR FILAMENT EJECTION AND 35 CORONAL MASS EJECTIONS, ONE OF WHICH WAS TYPE IV (360 deg) AND 2 A TYPE II (angular width 90-180 deg), HAVE BEEN OBSERVED. ----------------------------------------------------------------- FLARES >M1 X-RAY CLASSES to tm te localization Class E(1-8A) AR RII/IV CME X-ray/Ïp J/m-2 21.12 0519 0538 0549 S10W61L067 M4.2/1N 4.3E-02 13519 21.12 2342 0022 0004 S10W75L067 M3.3 13519 24.12 1109 1118 1124 S20W27L343 M2.9/1N 1.5E-02 13529 24.12 1637 1649 1709 S17W33L343 M2.6/1F 1.7E-02 13529 24.12 1921 1951 2016 S20E89L226 M1.1 DSF (EPL) to te localization l deg. Fl AR CMEtype/to 21.12 0200 S25E60L 40 CME/0423 23.12 0625 0712 N03W27L322 15 24.12 0920 N48W35L330 22 CME/1224 24.12 1438 S20E48L >10 CME/1548 ------------------------------------------------------------------- NEXT WEEK FLARE ACTIVITY WILL BE AT A LOW AND MODERATE LEVELS. ON THE VISIBLE SOLAR DISK THE FOLLOWING GEOEFFECTIVE CORONAL HOLES WERE OBSERVED: sign N end E end S end W end Sch EE R G Spacecrafts * - low geoeffectivity, the substorms with duration <6 h only. Sch - CH area in % solar hemisphere near the central meridian on https://www.solarmonitor.org/; n/d - no data; R - solar rotations; EE-date of possible geomagnetic disturbance in the Earth's environment. G(0-5)-geoeffectivity in last solar rotation on the middle latitudes. A-active geomagnetic condition. ---------------------------------------------------------------------- FROM 12.12/0000 UT THE EARTH MOVED TO THE "+" SECTOR OF THE INTERPLA- NETARY MAGNETIC FIELD. NEXT SECTOR BOUNDARY "+/-" EXPECTED 28.12. ----------------------------------------------------------------------- DECEMBER 18 19 20 21 22 23 24 DECEMBER Wus 137 144 133 138 157 123 113 F10.7 161 179 195 194 187 174 183 èbcg ó1.6 ó1.5 ó1.6 C1.3 C1.2 C1.0 C1.2 GOES Sp 390 750 1160 940 1030 960 900 msh N 3 1 1 2 IMF + + + + + + + DSCOVR Å>2 1.2å+6 1.5E+6 1.9E+6 6.3E+7 8.7E+7 4.0å+7 3.2å+6 GOES Ie>2 102 208 852 1273 1867 1065 228 pfU Ap 25 10 10 4 3 5 9 nô Dst nô KIOTO Amsc 17 10 10 5 2 6 9 nô IZMIRAN -------------------------------------------------------------------- Å>2 - Daily Electron Fluency e/(cm2-ster-day) with E>2 MeV. Ie>2 - the maximum intensity of electron flux on geostationary orbits for days according to GOES-18 in (electrons/cm*2/s.sr) for events F>1000 pfu. A HIGH LEVEL OF FLUX OF HIGH-ENERGY ELECTRONS WITH E>2 MeV STARTED ON 21.12/1530 UT AND WAS OBSERVED ON 21-23.12. NEXT WEEK A HIGH LEVEL OF HIGH-ENERGY ELECTRON FLUX WITH å>2 MeV NOT BE EXPECTED. THE GEOMAGNETIC CONDITION CHANGED FROM ACTIVE (9-hour of SUBSTORM G2-intencity 18.12 ACCORDING OF THE CENTER IN BOUL- DER DATA) TO UNSETTLED AND QUITE ON THE OTHER DAYS. ON NEXT WEEK THE GEOMAGNETIC CONDITION PROMISES TO BE UNSET- TLED AND QUITE. THERE ARE NO GEOEFFECTIVE CHs ON THE VISIBLE SOLAR DISC. HIGHLIGHT AND FORECAST COMPOSED FROM DATA: NOAA SWPC, BOULDER, USA http://www.swpc.noaa.gov, THE SOLAR INFLUENCES DATA ANALYSIS CENTRE, SIDC, BRUSSELS, BELGIUM http://sidc.oma.be/index.php3, THE IZMIRAN, MOSCOW, TROITSK, RUSSIA http://www.izmiran.ru V.Ishkov