Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 18 - 24.09.2017, Forecast on 25.09 - 02.10.2017, Carrington Rotation 2195 (12,73.09.2017) Earth above the ecliptic (7.14 - 7,01) deg. (S23 - N37 is geoeffectiveness zone) SUNSPOT-FORMING ACTIVITY WAS ON THE LOW LEVEL AT 20-22.09 AND VE- RY LOW IN OTHER DAYS. THE ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR THE PERIOD W=011+02/-04 (Wn = 016+05/-05). ON THE VISIB- LE SOLAR DISK 2 - 1 SMALL AND QUITE SUNSPOT GROUP. NEXT WEEK LEVEL OF SUNSPOT-FORMING ACTIVITY WILL REMAIN ON THE MID- DLE AND LOW DUE TO THE APPEARANCE FROM THE E-limb OF SUNSPOT GROUP AR12682 (AR12673 AT THE LAST ROTATION). MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR THE NEXT WEEK IS W=030+20/-10. FLARE ACTIVITY WAS AT THE VERY LOW LEVEL . THERE WERE THREE SOLAR FILAMENT EJECTIONS OCCURRENCES THROUGH THE PERIOD. ACCORDING TO THE DATA FROM SOHO AND STEREO CORONOGRAPHS >4 CME HAVE BEEN OBSERVED. ---------------------------------------------------------------------- FLARES to tm te local. Class E(1-8A) AR RII/IV CME X-ray/Ïp J/m-2 DSF to te ËÏÏÒÄÉÎÁÔÙ l × ÇÒÁÄ. Fl Aï CME/to 18.09 >0944 >2259 N37W07L288 6 19.09 0812 1233 S32E64L204 22 19.09 >0938 >2257 S25E44L224 7 --------------------------------------------------------------------- NEXT WEEK FLARE ACTIVITY WILL BE AT THE VERY LOW AND LOW LEVELS, BUT IN THE CASE OF NEW MAGNETIC FLUXES IN AR12682 APPEARANCE - AT THE ME- DIUM AND HIGH LEVELS. AS THE BACKGROUND OF THE SOFT X-RAY RADIATION SHOWS THAT AR12682 IS A QUIET SUNSPOT GROUP OF AVERAGE SIZE AND WITH LOW LEVEL OF FLARING ACTIVITY. HOWEVER, IT SHOULD BE UNDERSTOOD THAT 17.09 (NEAR THE CENTER OF THE SUN BACK SIDE) IN THIS SUNSPOT GROUP THERE WAS OCCURENCE A LARGE SOLAR FLARE WITH DUAL X-ray BURSTS 17/11 35 and 1345 UT. 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. CH - S01L242 S27L233 S30L241 S05L248 24.09 4 G0 SDO, SOHO... CH + N40L239 N40L205 S05L239 N17L269 26.09 4 G1 SDO, SOHO... Sch - CH Square in Mm**2 (in square megameters) near the central meri- dian on http://sdowww.lmsal.com/suntoday/; n/d - no data; R - solar rotations; EE-date of possible geomag. disturbance in the Earth's environment. G(0-5)-geoeffectivity in last solar rotation on the middle latitudes. A-active geomagnetic condition. ------------------------------------------------------------------------ 15.09/03 UT THE EARTH IS IN "+" SECTOR OF THE INTERPLANETARY MAGNE- TIC FIELD. NEXT SECTOR BOUNDARY -/+ EARTH SHOULD BE PASSED 0N 5.10. SEPTEMBER 18 19 20 21 22 23 24 SEPTEMBER Wus 012 011 022 022 022 012 022 F10.7 072 071 074 073 078 081 087 èbcg <á1.0 á2.0 A5.2 A1.1 A3.7 A7.6 A9.7 GOES Sp 080 050 120 140 140 090 270 msh N 1 1 IMF + + + + + + + DSCOVR Å>2 8.1å+8 1.5å+9 1.1E+9 1.4å+9 9.5å+8 7.0å+7 9.2å+8 GOES Ie>2 31067 34879 33761 30386 36942 2142 12883 pfu Ap 24 10 8 7 4 5 6 nô Dst nô KIOTO Amsc 24 10 8 7 4 5 8 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 GOES15 in (electrons/cm2.s.sr) for events > 1000 pfu. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT HAS BE- GIN 15.09/0830 UT AND 15-24.09 WAS OBSERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS OR- BIT IS EXPECTED 29.09 - 2.10. THE MINOR MAGNETIC STORM (G1, Ams=20, dur.= 15 h.) ACCORDING TO THE CENTRE IN BOULDER DATA WAS REGISTERED 18.09, HOWEVER IN IZMIRAN DA- TA AT THIS TIME NOTED THE (G0) SUBSTORM < 6 h. DURATION. IN OTHER DAYS THE GEOMAGNETIC CONDITION HAS BEEN UNSETTLED AND QUITE. NEXT WEEK THE GEOMAGNETIC CONDITION WILL BE UNSETTLED AND QUIET, EX- CEPT 24 AND 26.09, WHEN THE EARTH WILL BE PASSES SUCCESSIVE HIGH-SPE- ED STREAMS FROM TWO CORONAL HOLES. 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