Dear users, the sunspot-forming activity of October 2020 finally clarified the issue of the 24th SC end. With 98% probability cycle minimum point 24 - Dec. 2019. MAIN CHARACTERISTICS OF THE PAST 24 CYCLE SA: ------------------------------------------------------------------------------- Cycle Solar_Min Solar_Max Max_SSN Cycle_Length Min_to_Max Max_to_Min Year Mth Year Mth Years Mths Years Mths Years Mths ------------------------------------------------------------------------------- 24 2008 Dec 2014 Apr 116.4 11.0 132 5.3 64 5.7 68 More details in my report to IKI in February 2021. Thus, since January 2020, we have been living in the 25th solar cycle. V. Ishkov ------------------------------------------------------------------- THE RELATIVE MONTHLY MEAN SUNSPOT NUMBER ON SEPTEMBER 2020 HAS MADE Woct. = 8.6 14.4(n) THAT GIVES FOR 4 MONTH (2020, APRIL) OF DEVELOPMENT CURRENT 25 SOLAR CYCLE THE SMOOTHED MONTHLY MEAN SUNSPOT NUMBER W*apr. = 2.2 3.6 - × ÎÏ×ÏÊ ÓÉÓÔÅÍÅ W*mar. = 1.8 3.0 - × ÎÏ×ÏÊ ÓÉÓÔÅÍÅ 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) THE TIME OF THE CURRENT 25 CYCLE MAXIMUM - III 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 (69 observatories): 1.. 0 6.. 0 11.. 17 16.. 13 21.. 11 26.. 19 31.. 26 2.. 0 7.. 0 12.. 16 17.. 13 22.. 11 27.. 44M 3.. 0 8.. 6 13.. 0 18.. 23 23.. 22 28.. 28 4.. 0 9.. 23 14.. 5 19.. 16 24.. 21 29.. 37 5.. 0 10.. 15 15.. 13 20.. 13 25.. 22 30.. 31 Minimum : 0 on 1, 2, 3, 4, 5, 6, 7, 13 [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 2020, AND SMOOTHES ON 2020, APRIL 2020 F10.7oct. = 74.6 F*10.7apr.= 70.5 THE MONTHLY MEAN OF GEOMAGNETIC Ap-index ON OCTOBER 2020, AND SMOOTHES ON 2020, APRIL 2020 Ap oct. = 6.1 Ap*apr. = xxx --------------------------------------------------------------------- Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 26.10 - 01.11.2020, Forecast on 02 - 09.11.2020, Carrington Rotation 2236, 2237(05,01.10; 1,31.11.2020) Earth out of ecliptic (5.6 - 5.1) deg. (S20 - N35 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY REMAINED ON VERY LOW AND LOW LEVELS. ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE SUN- SPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD W=16+6 /-9 (Wn=27+9/-15). ON THE VISIBLE SOLAR DISC IN THE SOUTHERN HE- MISPHERE, TWO SUNSPOT GROUPS WERE OBSERVED, ONE SMALL, AND ONE ON 29.10 REACHED MEDIUM SIZES. BOTH OF ITS MADE A COMPLEX OF AC- TIVE REGIONS, THE FIRST IN THE CURRENT 25 SOLAR CYCLE. NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY WAS ON VERY LOW LEVEL. LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR NEXT WEEK IS W = 010+10/-10. FLARE ACTIVITY WAS AT LOW AND VERY LOW LEVEL. 15 SOLAR FLARE OF VERY LOW X-RAY CLASS CLASS "C", 76-CLASS "B", TWO SOLAR FILAMENT EJECTA AND 8 CORONAL MASS EJETIONS (26-28 é 30-31.10, 1.11) 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 DSF to te localization l deg. Fl AR CME/to 26.10 >1429 >0646 N24E01L071 23 27.10 0616 0621 N40E20L076 >10 -------------------------------------------------------------------- NEXT WEEK THE FLARE ACTIVITY IS EXPECTED AT VERY LOW LEVEL. ON THE VISIBLE SOLAR DISK THE FOLLOWING CORONAL HOLES WERE OBSERVED: --------------------------------------------------------------------- sign N end E end S end W end Sch EE R G Sp/craft * - 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 23.10/01 UT, THE EARTH IS IN THE "+" SECTOR OF THE INTERPLANETA- RY MAGNETIC FIELD. THE FOLLOWING THE NEXT SECTOR BOUNDARY "+/-" IT CAN BE EXPECT 3.11. ---------------------------------------------------------------------- OCTOBER 26 27 28 29 30 31 01 NOVEMBER Wus 017 022 036 035 032 026 012 F10.7 075 082 088 085 080 077 077 èbcg A2.2 ÷1.3 ÷1.1 ÷1.6 ÷1.2 A7.0 ÷1.5 GOES Sp 080 140 230 440 260 120 010 msh N 1 1 IMF + + + + + + + DSCOVR Å>2 4.7E+8 8.8å+8 7.4E+8 5.6E+8 4.3E+8 2.1E+8 3.9å+7 GOES Ie>2 16463 19940 21570 15796 8657 7325 1634 pfu Ap 15 9 12 14 15 6 10 nô Dst nô KIOTO Amsc 15 9 12 14 5 8 10 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 or- bits in days according to GOES-15 in (electrons/cm2.s.sr) for events > 1000 pfu. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT BEGUN 25.10/1320 AND OBSERVED 25.10 - 01.11. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS EXPECTED 02 - 06.11. ALL DAYS WEAKLY DISTURBED GEOMAGNETIC CONDITION WAS OBSERVED. SE- PARATE ISOLATED SUBSTORMS OF INTENSITY (G0) DURATION LESS THAN 6 h. REGISTERED (26,27,28 & 29.11). NEXT WEEK THE MOST PROBABLY QUIET AND UNSETTLED GEOMAGNETIC CON- DITION WILL BE OBSERVED. 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