------------------------------------------------------------------- THE PHASE OF MINIMUM - 25 CYCLE OF SOLAR ACTIVITY, THE BRANCH OF RISE: THE RELATIVE MONTHLY MEAN SUNSPOT NUMBER ON AUGUST 2021 HAS MADE Waug. = 13.4 22.4(in new system) THAT GIVES FOR 14 MONTH (2021, FEBRUARY) OF DEVELOPMENT CURRENT 25 SOLAR CYCLE THE SMOOTHED MONTHLY MEAN SUNSPOT NUMBER W*feb. = 11.5 19.1 - in new system W*jan. = 10.4 17.3 - 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 AUGUST 2021 (69 observatories): 1.. 8 6.. 9 11.. 19 16.. 20 21.. 17 26.. 48 31.. 40 2.. 13 7.. 0m 12.. 8 17.. 15 22.. 19 27.. 70 3.. 17 8.. 0m 13.. 10 18.. 13 23.. 17 28.. 75í 4.. 17 9.. 7 14.. 20 19.. 22 24.. 21 29.. 51 5.. 24 10.. 0m 15.. 23 20.. 13 25.. 35 30.. 43 [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 AUGUST 2021, AND SMOOTHES ON 2021, FEBRUARY F10.7aug. = 77.7 F*10.7feb.= 78.0 THE MONTHLY MEAN OF GEOMAGNETIC Ap-index ON AUGUST 2021, AND SMOOTHES ON 2021, FEBRUARY Ap aug.= 6.2 Ap*feb. = xxx --------------------------------------------------------------------- Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 28.08 - 12.09.2021, Forecast on 13 - 20.09.2021 Carrington Rotation 2248 (28,33.08.2021) Earth out of ecliptic (3.8 - 3.0) deg. (S30 - N32 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY WAS ON LOW,MIDDLE AND HIGH LEVELS. THE ESTIMATED MOST LIKELY WEEKLY AVERAGE VALUE OF THE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD IS W= 35+74/-15 (Wn= 59+65/-26). THERE ARE 1 LARGE, 2 MIDDLE (ALL ON S-HEMISPHERE) AND 11 SMALL QUITE SUNSPOT GROUPS ON VI- SIBLE SOLAR DISK, 3 (ON NORTH HEMISPHERE) HAS BEEN OBSERVED. NEXT WEEK SUNSPOT ACTIVITY WILL BE ON MIDDLE, LOW AND VERY LOW LEVELS. WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUM- BER IN THE INTERNATIONAL SYSTEM (old) FOR NEXT WEEK IS W=030+ 30/-10. FLARE ACTIVITY WAS AT MIDDLE AND LOW LEVELS. ONE FLARE OF X- RAY CLASS "M", 24 - CLASS "C", ~80 - CLASS "B"AND 31 CORONAL MASS EJECTIONS (30.08-1, 4-8, 10-12.09) 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 28.08 0539 0611 0813 S28W01L002 M4.7/1N 0.064 12860 IV/1,II/1 DSF to te localization l deg. Fl AR CME/to -------------------------------------------------------------------- NEXT WEEK THE FLARE ACTIVITY IS EXPECTED AT VERY LOW AND LOW 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 CH* - N20L052 N05L057 S05L056 N10L051 1.1% 27.08 R1 SDO,SOHO... * - 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. ---------------------------------------------------------------------- AFTER 31.08/07 UT THE EARTH IS IN THE "+" SECTOR OF THE INTERPLANETA- RY MAGNETIC FIELD. FOLLOWING SECTOR BOUNDARY "+/-" IT CAN BE EXPECT 18.08. ----------------------------------------------------------------------- AUGUST 28 29 30 31 01 02 03 04 SEPTEMBER Wus 044 077 041 037 035 033 033 068 F10.7 090 089 091 084 084 086 084 087 èbcg ÷1.0 ÷1.4 ÷2.8 ÷1.3 B1.2 ÷1.4 ÷1.4 ÷1.8 GOES Sp 400 330 240 250 230 290 190 200 msh N 1 1 3 IMF - - - -/+ + + + + DSCOVR Å>2 1.6å+3 7.7E+7 1.3E+8 2.5E+8 4.5E+7 2.8E+7 GOES Ie>2 10665 11665 4458 3240 3639 7837 1987 966 pfu Ap 14 8 7 7 6 5 6 6 nô Dst nô KIOTO Amsc 10 8 8 8 7 7 7 5 nô IZMIRAN ------------------------------------------------------------------------ ------------------------------------------------------------------------ SEPTEMBER 05 06 07 08 09 10 11 12 SEPTEMBER Wus 066 080 085 087 124 099 093 047 F10.7 094 100 101 100 100 096 092 088 èbcg ÷2.2 ÷2.5 ÷2.3 ÷2.4 B1.0 ÷1.0 ÷1.3 ÷2.2 GOES Sp 270 720 970 210 1000 1030 920 780 msh N 1 IMF + + + + + + + + DSCOVR Å>2 4.5å+7 5.3E+7 1.6å+7 2.5E+6 1.4E+6 1.6E+6 GOES Ie>2 2033 3283 1479 277 155 158 pfu Ap 6 6 8 14 6 9 7 6 nô Dst nô KIOTO Amsc 6 5 13 16 5 9 6 7 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 STARTED ON 28/0205 UT AND WAS OBSERVED 08/28-4.09, WITH A GREAT PROBABILITY FROM THE CORONAL HOLE SPECIFIED IN THE PREVIOUS ISSUE NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS NOT EXPECTED - NO GEOEFFECTIVE CORONAL HOLES. THE GEOMAGNETIC CONDITION WAS QUIET AND UNSETTLED ALL DAYS EXCEPT 8.09, WHEN A ACTIVE CONDITION (G1, 6 hours duration) ACCORDING TO IZMIRAN DATA HAVE BEEN OBSERVED. THE NEXT WEEK IS MOST PROBABLE A QUIET AND UNSETTLED GEOMAGNETIC CONDITION ALL DAYS. 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