Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 15 - 21.05.2017, Forecast on 22 - 29.05.2017, Carrington Rotation 2190, 2191 (29,63.04; 26,85.05.2017) Earth above the ecliptic (-2,6, -2,0) deg. (S34 - N26 is geoeffectiveness zone) SUNSPOT-FORMING ACTIVITY WAS ON LOW LEVEL ALL DAYS BUT 15.05 WERE SPOTLESS DAYS (37th DAY ON CURRENT YEAR). THE ESTIMATED, MOST LIKE- LY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE IN- TERNATIONAL SYSTEM (old) FOR THE PERIOD IS W= 12+9/-12 (Wn= 20+14/ -20). ON THE VISIBLE DISC OF THE SUN 0-3 SMALL QUITE SUNSPOT GROUP HAVE BEEN OBSERVED. NEXT WEEK SUNSPOT-FORMING ACTIVITY IS EXPECTED AT THE LOW LEVEL. THE ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR THE NEXT WEEK IS W = 25+15/-20. FLARE ACTIVITY WAS AT THE VERY LOW LEVEL ALL DAYS. 2 SOLAR FILAMENT EJECTIONS OCCURRENCES THROUGH THE PERIOD. ACCORDING TO THE SOHO AND STEREO CORONOGRAPHS DATA >5 CMEs 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 16.05 >0125 >1242 S07W59L196 6 17.05 >0927 >2330 S34E07l117 9 --------------------------------------------------------------------- NEXT WEEK FLARE ACTIVITY IS EXPECTED TO BE VERY LOW WITH A SLIGHT CHAN- CE FOR C-CLASS FLARES AFTER 23.05. 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 - N05L115 S12L100 S15L102 S05L127 20.05 10 1 SDO, SOHO... CH - S15L110 S05L080 S30L093 S20L111 21.05 10 2 SDO, SOHO... CH - N28L091 N20L085 N00L098 N18L112 21.05 1 SDO, SOHO... óî + N28L032 N23L027 N20L034 N25L036 28.05 1 SDO, SOHO... The first two may have one CH; 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. ------------------------------------------------------------------------ AFTER 4.05/0224 UT THE EARTH IS IN "-" SECTOR OF THE INTERPLANETARY MAG- NETIC FIELD. PERIOD FROM 15 TO 19.05 THE SIGN OF THE SECTOR SHORTLY CHAN- GED, REMAINING A LARGE PART OF TIME IN THE "-" SECTOR. NEXT SECTOR BORDER - / + EARTH SHOULD BE PASSED 0N 27.05. íáY 15 16 17 18 19 20 21 íáY Wus 000 023 013 024 024 022 035 F10.7 071 072 071 072 072 072 074 èbcg A3.9 á4.2 á4.8 á5.4 á5.0 á5.0 á5.1 GOES Sp 000 030 030 030 030 030 070 msh N 2 1 1 IMF -/+ +/- - -/+ - - - DSCOVR Å>2 1.3å+6 3.3å+6 1.0E+7 3.1E+6 6.3å+6 3.0å+7 4.3å+8 GOES Ie>2 112 256 149 329 1445 13008 pfu Ap 14 8 8 11 11 4 10 nô BOULDER Dst -24 -37 -23 nô KIOTO Amsc 13 9 9 7 17 4 9 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 BEGAN 20.05/1705 UT IN RESPONSE TO ELEVATED WIND SPEED FROM CH HSS INFLU- ENCE AND OBSERVED 20 - 21.05. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSTATIONARY ORBIT OF VERY HIGH LEVEL IS EXPECTED 22 - 29.05. GEOMAGNETIC CONDITION WAS QUIET AND UNSETTLED ALL DAYS, EXCEPT 20.05 WHEN THE MINOR MAGNETIC STORM (G0, Ams= 27, dur.= 18 h.) IS NOTED BY THE CENTER IN BOULDER. ACCORDING TO IZMIRAN DATA, THIS DISTURBATION WAS 9-hour SUBSTORM INTENSITY (G0). THIS DISTURBATION IS THE CONSE- QUENCE OF THE HIGH-SPEED STREAM FROM THE CORONAL HOLES "-" POLARITY. ON THE NEXT WEEK THE QUIET AND UNSETTLED GEOMAGNETIC CONDITION TO BE EXPECTED. 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