25 CYCLE OF SOLAR ACTIVITY, THE BRANCH OF RISE: THE PHASE OF MINIMUM THE RELATIVE MONTHLY MEAN SUNSPOT NUMBER ON OCTOBER 2021 HAS MADE Woct. = 22.9 38.1(in new system) THAT GIVES FOR 16 MONTH (2021, APRIL) OF DEVELOPMENT CURRENT 25 SOLAR CYCLE THE SMOOTHED MONTHLY MEAN SUNSPOT NUMBER W*oct. = 14.9 24.9 - in new system W*mar. = 13.1 21.8 - in new system On July 1, 2015 Centre in Brussels moved to a new system of calcu- lation the relative number of sunspots and practically all of the values were replaced throughout the numbered series of Wolf numbers (see link). While there is addictive, I recalculated (0.6) to the old system, but only W*, and present below the new values for the minimum and maximum of 25 cycles SA. THE BEGINNING OF 25 SOLAR CYCLE - I 2020 with W*=1.3; (1.8n) MAXIMUM OF THE CURRENT 25 CYCLE - VI 2024 - Wmax =90-100; (150n) THE END OF 25 SOLAR CYCLE (THE POINT OF MINIMUM) - I - VI 2031; Provisional daily International Sunspot Numbers for OCTOBER 2021 (70 observatories): 1.. 36 6.. 26 11.. 30 16.. 11 21.. 18 26.. 92 31.. 68 2.. 34 7.. 16 12.. 18 17.. 0m 22.. 37 27..104M 3.. 26 8.. 19 13.. 20 18.. 18 23.. 50 28..100 4.. 35 9.. 24 14.. 21 19.. 13 24.. 41 29.. 85 5.. 31 10.. 39 15.. 12 20.. 12 25.. 68 30.. 78 [The daily value W in old system close to true (in a minimum phase) can be received, multiplying by k = 0.6]. THE MONTHLY MEAN OF OBSERVED RADIO FLUX OF THE 10 cm (2800 MHz) ON OCTOBER 2021, AND SMOOTHES ON 2021, APRIL F10.7oct. = XX.0 F*10.7apr.= XX.0 THE MONTHLY MEAN OF GEOMAGNETIC Ap-index ON OCTOBER 2021, AND SMOOTHES ON 2021, APRIL Ap oct.= XX Ap*apr. = xxx --------------------------------------------------------------------- Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 25 - 31.10.2021, Forecast on 01 - 08.10.2021 Carrington Rotations 2249, 2250 (24,59.09; 21,88.10.2021) Earth out of ecliptic (-1.5 - -1.1) deg. (S30 - N30 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY WAS ON MIDDLE AND LOW LE- VELS. ESTIMATED MOST LIKELY WEEKLY AVERAGE VALUE OF THE SUN- SPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD IS W= 52+4/-6 (Wn= 86+10/-10). ON VISIBLE SOLAR DISK AT THE SAME TIME UP TO FIVE SUNSPOT GROUPS: 2 MIDDLE AND 3 SMALL SIZE, 2 IN NORTHERN HEMISPHERE HAS BEEN OBSERVED. NEXT WEEK SUNSPOT ACTIVITY WILL BE ON MIDDLE AND LOW LEVELS. WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE IN- TERNATIONAL SYSTEM (old) FOR NEXT WEEK IS W=050+50/-30. FLARE ACTIVITY WAS AT HIGH, MIDDLE AND LOW LEVELS. ONE FLARE X-RAY CLASS "X", 63 FLARES CLASS "C", 43 - CLASS "B", ONE SO- LAR FILAMENT EJECTION AND 19 CORONAL MASS EJECTIONS (25-30.10), ONE WHICH WAS TYPE II AND ONE -IV, HAVE BEEN OBSERVED. ------------------------------------------------------------------- FLARES >M1 X-RAY CLASSES to tm te local. Class E(1-8A) AR RII/IV CME X-ray/Ïp J/m-2 26.10 0240 0254 0247 N14E88L214 M1.3/BSL 5.8E-03 12891 26.10 1542 1602 1557 N13E89L214 M1.0/BSL 4.8E-03 12891 28.10 0730 0745 0740 S31E02L280 M1.4/SF 4.7E-03 12887 28.10 1019 1037 1028 S30E00L280 M2.2/1F 1.3E-02 12887 28.10 1517 1548 1535 S28W01L214 X1.0/2N 9.1E-02 12887 II/3|1457 IV/2 CME/1548 29.10 0222 0253 0242 N16E53L214 M1.5/1N 1.4E-02 12891 DSF (EPL) to te localization l deg. Fl AR CME/to 29.10 1838 1852 0.15 B7.2 12891 CME/1912 -------------------------------------------------------------------- NEXT WEEK THE FLARE ACTIVITY IS EXPECTED AT LOW AND MIDDLE LEVELS. ON THE VISIBLE SOLAR DISK THE FOLLOWING CORONAL HOLES WERE OBSERVED: --------------------------------------------------------------------- sign N end E end S end W end Sch EE R G Spacecraft * - 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. ---------------------------------------------------------------------- 30.10/2040 UT THE EARTH IS IN THE "+" SECTOR OF THE INTERPLANETARY MAG- NETIC FIELD. FOLLOWING SECTOR BOUNDARY "+/-" IT CAN BE EXPECT 6.11. ----------------------------------------------------------------------- OCTOBER 25 26 27 28 29 30 31 OCTOBER Wus 081 095 091 096 082 076 083 F10.7 101 109 111 112 108 107 103 èbcg B2.8 ÷7.9 ÷5.8 ÷6.1 ÷3.6 B3.3 ÷3.5 GOES Sp 470 820 660 700 710 470 480 msh N 2 1 1 1 IMF ~ - - - - +/- - DSCOVR Å>2 1.6E+6 1.5E+6 1.6E+6 3.1E+6 1.8å+6 1.2E+6 1.2E+6 GOES Ie>2 347 152 138 228 242 133 133 pfu Ap 5 5 3 3 3 10 20 nô Dst nô KIOTO Amsc 6 4 2 2 2 9 12 IZMIRAN ------------------------------------------------------------------------ Å>2 - Daily Electron Fluency e/(cm2-ster-day) with E>2 MeV. Ie>2 - the maximum intensity of electron flux in geostationary or- bits in days according to GOES-15 in (electrons/cm2.s.sr) for events > 1000 pfu. Pr>10 MeV: 28.10/1532 UT; max 29/~0250 UT - 29 pfu; Te=01.11/0100 UT (next Pr-event); THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT NOT OBSERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS NOT EXPECTED. THE GEOMAGNETIC CONDITION REMAINED QUIET AND UNSETTLED ALL DAYS EX- CEPT 31.10, WHEN AFTER ARRIVING CME FROM SOLAR FLARE OF X-RAY CLASS X1 2 SUBSTORM OF THE INTENCITY G1 AND G0 WERE MARKED BY THE BOULDER CENTER DATA. ACCORDING TO IZMIRAN DATA MARKED ONE SUBSTORM G0 - ALL SUBSTORM DURATION 3 h ONLY. THE QUESTION OF THE LOW GEOEFFICIENCY OF THIS EVENT REQUIRES A SEPARATE STUDY. THE NEXT WEEK MOST PROBABLE QUIET AND UNSETTLED GEOMAGNETIC CONDITION. 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