------------------------------------------------------------------- THE RELATIVE MONTHLY MEAN SUNSPOT NUMBER ON APRIL 2019 HAS MADE Wmarch = 5.5 9.1(n) THAT GIVES FOR 117 MONTH (2018, OCTOBER) OF DEVELOPMENT CURRENT 24 SOLAR CYCLE THE SMOOTHED MONTHLY MEAN SUNSPOT NUMBER W*oct. = 4.1 6.9 - in new sestem W*sep. = 4.0 6.6 - in new sestem 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 24 cycles SA. THE BEGINNING OF 24 SOLAR CYCLE - I 2009 with W*=1.8; (2.2) THE TIME OF THE CURRENT CYCLE MAXIMUM - IV 2014, - Wmax = 82;(116.4) THE END OF 24 SOLAR CYCLE (THE POINT OF MINIMUM) - I - VI 2020; OTHER SC FORECAST: SM : SIDC classical method : based on an interpolation of Waldmeier's standard curves; the estimated error ranges from 7% (first month) to 35% (last month) - December 2019; CM : Combined method : the combined method is a regression technique coupling a dynamo-based estimator with Waldmeier's idea of standard curves, due to K. Denkmayr - October 2018; NOAA - February 2019. The last two, in my opinion, are inadequate, since such short, low SCs were not observed. The observed magnetic structures corresponding SO 25 (~ 20), can be seen http://www.solen.info/solar/cycle25_spots.html THE INTERNATIONAL DAILY VALUE OF RELATIVE SUNSPOT NUMBER (IN NEW SYS- TEM) FOR 2019, APRIL ACCORDING DATA OF 70 SOLAR OBSERVATORIES HAS MADE: 1.. 14 6.. 0 11.. 12 16.. 11 21.. 5 26.. 0 2.. 17 7.. 11 12.. 13 17.. 16 22.. 0 27.. 0 3.. 19 8.. 12 13.. 16 18.. 24í 23.. 0 28.. 0 4.. 11 9.. 12 14.. 14 19.. 24í 24.. 0 29.. 0 5.. 5 10.. 13 15.. 12 20.. 11 25.. 0 30.. 0 Minimum : 0 on 6, 22, 23, 24, 25, 26, 27, 28, 29, 30 [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 APRIL 2019, AND SMOOTHES ON 2018, OCTOBER F10.7apr. = 72.4 F*10.7oct.= 70.3 THE MONTHLY MEAN OF GEOMAGNETIC Ap-index ON MARCH 2019, AND SMOOTHES ON 2018, SEPTEMBER Ap apr = 6.1 Ap*oct. = 7.1 ------------------------------------------------------------------- Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 29.04 - 05.05.2019, Forecast on 06 - 12.05.2019, Carrington Rotation 2216, 2217 (08,8.04; 06,0.05.2019) Earth out of ecliptic (-5.3 - -4.7) deg. (S30 - N20 is zone of geoeffectiveness) THE SUNSPOT-FORMING SOLAR ACTIVITY WAS AT THE VERY LOW LEVEL, THE SUN WAS SPOTLESS BEFORE 3.05 (74 DAYS ON 2019). ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUM- BER IN THE INTERNATIONAL SYSTEM (old) FOR PERIOD W = 3+4/-3 (Wn=5+6/-5). ONE SUBSPOT GROUP AFTER 3.05 ON SOLAR VISIBLE DISC HAVE BEEN OBSERVED. NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY WILL AT VERY LOW LEVEL. LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR THE NEXT WEEK IS W=010+20/-10. FLARE ACTIVITY WAS AT THE LOW LEVEL AT 3-5.05 AND THE VERY LOW LEVELS IN OTHER DAYS. NO FILAMENT EJECTION AND 14 CORONAL MASS EJECTIONS 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 × ÇÒÁÄ. Fl AR CME/to -------------------------------------------------------------------- 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 Space Obser. óî - N10L235 S10L234 S40L202 S20L182 <13.4 23.04 8 - ACE SOHO... óî - N10L108 S02L121 S28L106 S15L083 <10.6 02.05 4 - ACE SOHO... 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 23.04/22 UT EARTH IS IN "-" SECTOR OF THE INTERPLANETARY MAGNE- TIC FIELD. NEXT SECTOR BOUNDARY -/+ THE EARTH MUST PASS 15.05. ----------------------------------------------------------------------- áðòåìø 29 30 01 02 03 04 05 áðòåìø Wus 000 000 000 000 011 012 013 F10.7 067 069 068 068 070 072 074 èbcg á5.9 á5.7 á5.9 á6.5 A6.0 B1.2 B1.0 GOES Sp 000 000 000 000 260 270 280 msh N 1 IMF - - - - - - - DSCOVR Å>2 2.5E+6 2.6E+6 1.8E+6 6.2+7 1.7å+8 4.3E+7 4.7å+7 GOES Ie>2 2978 6155 4753 1177 pfu Ap 5 5 11 12 7 10 4 nô Dst nô KIOTO Amsc 6 6 13 9 4 11 5 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 NOT OB- SERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS OR- BIT IS NOT EXPECTED. GEOMAGNETIC CONDITION AT MEDIUM LATITUDES UP REMAINS QUIET AND UNSET- TLED. NEXT PERIOD THE MOST PROBABLE QUIET AND UNSETTLED GEOMAGNETIC CONDI- TION IS EXPECTED. CORONAL HOLE TOO "FRIABLE" THAT TO GIVE A SUBSTANTI- VE GEOMAGNETIC DISTURBANCE, ALTHOUGH THE AURORA 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