Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 21 - 27.05.2018, Forecast on 28.05 - 02.06.2018, Carrington Rotation 2004 (16,45.05.2018) Earth out of ecliptic (-1.0 - -0.8) deg. (S25 - N25 is zone of geoeffectiveness) THE SUNSPOT-FORMING ACTIVITY OF THE SUN WAS ON VERY LOW, MID- DLE AND LOW LEVEL. THE ESTIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYS- TEM (old) FOR THE PERIOD W= 015+008/-008 (Wn = 024+013/-012). ON THE VISIBLE DISC OF THE SUN, THE THREE SMALL QUIET SUNSPOT GROUPS, ALL IN THE NORTHERN HEMISPHERE, HAVE BEEN OBSERVED. NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY WILL BE ON THE LOW AND VERY LOW. LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUN- SPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR THE NEXT WEEK IS W=010+10/-10. THE FLARE ACTIVITY WAS ON THE LOW LEVEL 23.05 AND VERY LOW IN OTHER DAYS. ONE SOLAR FILAMENT EJECTIONS AND ONE CORONAL MASS EJECTIONS HAVE BEEN OBSERVED. ---------------------------------------------------------------------- FLARES FROM M1 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 25.05 >1712 >0452 S04W47l178 10 --------------------------------------------------------------------- NEXT WEEK THE FLARE ACTIVITY IS EXPECTED AT VERY 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 Space Obser. CH + S12L302 S15L308 S25L299 S12L294 22.05 1 G0 SDO,SOHO... CH + Pn N40L240 N20L205 N25L200 107500 26.05 1 SDO,SOHO... CH - N05L195 S13L238 S20L208 S16L180 31.05 2 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. ------------------------------------------------------------------------ AFTER 24.05/1600 UT EARTH IS IN "+" SECTOR OF INTERPLANETARY MAG- NETIC FIELD. NEXT SECTOR BOUNDARY +/- THE EARTH MUST PASS 01.06. MAY 21 22 23 24 25 26 27 MAY Wus 012 012 030 039 032 026 027 F10.7 070 071 073 074 076 073 075 èbcg á1.0 á2.4 á5.1 á4.4 á5.3 á4.5 á4.1 GOES Sp 020 020 050 140 080 070 050 msh N IMF - - - -/+ +/~ +/~ +/~ DSCOVR Å>2 3.9E+7 3.0E+7 5.4E+6 4.2å+6 8.2å+6 1.2å+7 1.3å+7 GOES Ie>2 846 954 812 120 197 283 320 pfu Ap 2 5 10 4 3 4 4 nô Dst nô KIOTO Amsc 2 6 9 4 4 3 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 GOES15 in (electrons/cm2.s.sr) for events > 1000 pfu. THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT NOT OBSERVED. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS EXPECTED AFTER 01.06. THE ENTIRE PERIOD THE GEOMAGNETIC CONDITION WAS QUITE AND UNSET- TLED. THE NEXT WEEK THE GEOMAGNETIC CONDITION IS EXPECTED TO BE PRIMA- RILY QUITE AND UNSETTLED, WITH A CHANCE FOR ACTIVE CONDITIONS 31. 05 - 1.06 WITH PERIODS OF MINOR STORMING (probability ~ 30%), DUE TO INFLUENCE FROM HIGH SPEED STREAM FROM TRANS-EQUATORIAL CORONAL HOLE. 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