25 CYCLE OF SOLAR ACTIVITY, THE BRANCH OF RISE: THE PHASE OF RISE Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 10 - 16.04.2023 Forecast on 17 - 24.04.2023 Carrington Rotation 2269, 2270 (24,4.04; 20,7.04.2023) Earth out of ecliptic (-6.0 - -5.3 deg.) (S34 - N26 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY CHANGED FROM HIGH TO MIDDLE LEVELS. ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE SUN- SPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD IS W= 069+28/-17 (Wn=115+48/-29). ON THE VISIBLE SOLAR DISC OBSERVED UP 8 SUNSPOT GROUPS AND UP 5 OF THEM LOCALIZED ON THE SOUTH HE- MISPHERE. NEXT WEEK SUNSPOT ACTIVITY EXPECTED ON THE LOW AND MIDDLE LE- VELS. WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM FOR NEXT WEEK IS W=90+40/-50. FLARE ACTIVITY HAS BEEN AT MIDDLE AND LOW LEVELS. 1 FLARE OF X-RAY CLASS M, 83 -CLASS ó, 2 EJECTION OF SOLAR FILAMENTS AND 32 CORONAL MASS EJECTIONS, ONE OF WHICH WAS TYPE IV (HALO), HA- VE 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 21.04 1744 1812 2001 S22W11L001 M1.7/2N 3.9E-021 3283 II|580/IV/2 DSF (EPL) to te localization l deg. Fl AR CMEtype/to 21.04 ~1744 <1812 S27W02L340 >10 M1.7 13283 CMEIV/1812 24.04 0030 0439 SE EPL 0.19/B.5A CME/0200 ------------------------------------------------------------------- NEXT WEEK FLARE ACTIVITY WILL BE AT LOW AND MIDDLE 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 Spacecraft CH* - S35L320 S65L034 PS S55L040 4.0 22.04 1 õíâ SD0,HINOôORI CH - N15L300 S08L340 S20L308 N05L299 6.0 27.04 4 ííâ SD0,HINOôORI * - 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 19.04/2015 UT THE EARTH IS IN "-" SECTOR OF INTERPLANETARY MAGNE- TIC FIELDS. NEXT SECTOR BOUNDARY "-/+" IT CAN EXPECTED 8.05. ------------------------------------------------------------------- APRIL 17 18 19 20 21 22 23 APRIL Wus 162 148 113 097 114 087 086 F10.7 167 153 147 147 151 141 135 èbcg ó1.2 ó1.0 ó1.0 ó1.0 ÷6.5 ÷7.7 ÷6.1 GOES Sp 890 760 770 520 630 550 540 msh N 1 1 IMF -/+ + +/- - - - - DSCOVR Å>2 1.4å+6 1.5E+6 1.4E+6 14E+6 1.4å+6 2.5å+6 1.5E+6 GOES Ie>2 141 198 192 112 131 143 157 pfU Ap 4 14 10 4 8 6 86 nô Dst -16 -153 nô KIOTO Amsc 4 17 11 4 10 7 40 nô IZMIRAN --------------------------------------------------------------------- Å>2 - Daily Electron Fluency e/(cm2-ster-day) with E>2 MeV. Ie>2 - the maximum intensity of electron flux in geostationary orbits in days according to GOES-15 in (electrons/cm*2/s.sr) for events F> 1000 pfu. Pr>10 MeV: to-22/0140; max 26 pfu-23/18; te- continued... The maximum proton flux is associated with the arrival of the inter- planetary shock wave from the flare on April21.04/1744 UT. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT NOT OBSERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX WITH å>2 MeV IS NOT EXPECTED. THE GEOMAGNETIC ENVIRONMENT REMAINED UNSETTLTD AND QUITE ALL DAYS EXCEPT 18.04, WHEN A 9-hour SUBSTORM OF INTENSITY (G1) WAS OBSER- VED-THE ARRIVAL OF A DISTURBATION FROM THE EJECTION OF FILAMENT 15.04. HOWEVER, AFTER ARRIVAL TO THE EARTH THE DISTURBATION FROM M1.7/2N FLARE (SI - 23.04/1737 UT), A LARGE MAGNETIC STORM (G4) STARTED ACCORDING TO THE BOULDER CENTER DATA, WHICH CONTINUES (April 24/1500). ACCORDING TO IZMIRAN DATA, ITS INTENSITY IS G4. NEXT WEEK 24-25.04 THE MAGNETIC STORM IS EXPECTED TO CONTINUE. 26-27.04 THE EARTH WILL ENTER THE HIGH-SPEED FLOW FROM THE CORO- NAL HOLE. PROBABILITY OF A MINOR MAGNETIC STORM IS NOT LESS THAN 40%. ON THE OTHER DAYS, A UNSETTLED GEOMAGNETIC ENVIRONMENT IS MOST PROBABLE. THE NEXT WEEK THE GEOMAGNETIC CONDITION WILL BE MOST PROBABLY UNSET- TLED AND QUIET. 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