Weekly Bulletin on Solar and Geomagnetic Activity Highlights on 09 - 15.04.2018, Forecast on 16 - 23.04.2018, Carrington Rotation 2002, 2003 (22.94.03; 19,22.04.2018) Earth out of ecliptic (-3.3 - -2.8) deg. (S28 - N25 is zone of geoeffectiveness) THE SUNSPOT-FORMING ACTIVITY OF THE SUN WAS ON VERY LOW LEVEL, THE VISIBLE DISK WAS SPOTLESS 9-12 AND 15.04 (64d. ON THE CUR- RENT YEAR). 13.04 NEAR EAST LIMB (E51) THE SMALL SUNSPOT GRO- UP WAS FORMED (THE ACTIVE REGION WAS FORMED BY 11.04). THE ES- TIMATED, MOST LIKELY WEEKLY AVERAGE VALUE OF THE RELATIVE SUN- SPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR THE PERIOD W=003+5/-3 (Wn=005+8/-5). ON THE VISIBLE DISK IT WAS OBSERVED ONE SMALL SUNSPOT GROUP. IT IS INTERESTING TO NOTE THAT 10-11. 04 ON ALL SURFACE OF THE SUN, THE IMPULSE OF FORMATION OF AC- TIVE REGIONS WAS OBSERVED. 10.04 ON DISTANCE ~90 deg. TO THE EAST ON THE SAME HELIOLATITUDE IT WAS FORMED SMALL AR. 11.04. ALONG WITH AR OF THE VISIBLE HEMISPHERE ON DISTANCE OF 120 deg. ON THE EAST AT THE SAME HELIOLATITUDE IT WAS FORMED SIMILAR BY THE SIZES TO FIRST AR, IT IS POSSIBLE WITH SUNSPOTS. NEXT WEEK THE LEVEL OF SUNSPOT ACTIVITY WILL BE ON THE VERY LOW LEVEL AND SUN IS EXPECTED SPOTLESS WITH HIGH LIKELY. LIKE- LY WEEKLY AVERAGE VALUE OF THE RELATIVE SUNSPOT NUMBER IN THE INTERNATIONAL SYSTEM (old) FOR THE NEXT WEEK IS W=010+10/-10. FLARE ACTIVITY WAS ON THE VERY LOW LEVELS ON PERIOD. NO EJECTA OF SOLAR FILAMENTS AND FIVE CORONAL MASS EJECTIONS (11, 14 -15. 04) 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 --------------------------------------------------------------------- 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. óî + N15L217 N12L223 S10L167 S05L160 31400 10.04 6 G0 SOHO,SDO... óî - N20L050 N17L090 S35L050 N10L002 17.04 4 G0 SOHO,SDO... 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 12.04/0430 UT EARTH IS IN "-" SECTOR OF INTERPLANETARY MAGNETIC FIELD. NEXT SECTOR BOUNDARY -/+ THE EARTH MUST PASS 25.04. áðòåìø 09 10 11 12 13 14 15 áðòåìø Wus 000 000 000 013 014 011 000 F10.7 069 069 068 070 070 070 071 èbcg <á1.0 <á1.0 <á1.0 á1.9 á2.1 á2.0 á1.9 GOES Sp 000 000 000 030 030 000 000 msh N IMF + + + +/- ~/- -/~ ~/- DSCOVR Å>2 6.0E+6 4.2E+7 3.2E+8 8.0å+8 4.9å+8 3.5å+8 2.3å+8 GOES Ie>2 301 1937 10905 22185 25451 20707 8310 pfu Ap 10 16 16 9 9 6 5 nô Dst nô KIOTO Amsc 9 14 11 10 11 5 6 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 BEGAN AT 10.04/0430 UT AND OBSERVED 10.03 - 16.04. NEXT WEEK THE GREATER THAN 2 MeV ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS EXPECTED 16 - 23.04. GEOMAGNETIC CONDITION WAS ACTIVE (10 - 11.04) AND UNSETTLED IN OTHER DAYS. NEXT WEEK THE GEOMAGNETIC CONDITION SHOULD BE ACTIVE (17-19.04) AND UNSETTLED IN OTHER 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