Solar activity began the period at low levels, increased to high levels by midweek, and ended the period at moderate levels. In total, 17 solar flares were measured at or above the M1 (Minor) threshold from June 9 – 15, three of which were X-class (R3-Strong) flares.
Region 2087 (S18, L=155, class/area=Eac/220 on June 13) was the most productive region of the period and kicked things off with a pair of X-class flares on June 10. The first event was an impulsive X2/Sf (R3-Strong) flare at 10/11:42 UTC with an associated Tenflare (1400 sfu), a Type-II (878 km/s) radio sweep, and with a subsequent Coronal Mass Ejection (CME) visible off the east limb in SOHO/LASCO C2 coronagraph imagery beginning at 10/12:00 UTC.
The second event was an X1/1f (R3-Strong) flare at 10/12:52 with an associated Tenflare (530 sfu), a Type-IV radio sweep, and a subsequent partial halo CME visible off the east limb in C2 coronagraph imagery beginning at 10/13:25 UTC.
Post-event forecaster analysis and WSA-ENLIL model output suggested that these CMEs would narrowly pass by Earth on or around June 14 at 19:00 UTC, but were ultimately not observed in ACE solar wind data or at ground-based magnetometer stations.
Weekly GOES satellite X-ray and proton plots – Week beginning June 09, 2014. Image credit: SWPC
Data by SWPC
Region 2087 struck again on June 11, producing an X1/Sf (R3-Strong) flare at 09:06 UTC with an associated Tenflare (190 sfu) and a subsequent CME off the east limb first visible in C2 coronagraph imagery at 11/09:24 UTC, which was later determined to be directed away from the Sun-Earth line.
In addition to the three X-class flares detailed above, Region 2087 produced an additional seven M-class flares in the R1 (Minor) category.
Regions 2080, 2085, and 2089 were certainly outclassed by Region 2087 but would not go quietly. Region 2080 (S12, L=261, class/area=Dkc/340 on June 08) contributed an M1/Sn flare at 11/05:34 UTC, Region 2085 (S20, L=257, class/area=Ekc/490 on June 12) produced an M1/1B flare at 12/09:37 UTC and an M3/1f flare at 12/22:16 UTC with an associated Tenflare (220 sfu), a Type-II (1679 km/s) radio sweep, and a Type-IV radio sweep.
Finally, Region 2089 (N18, L=197, class/area=Dai/150 on June 15) produced an M1/Sf flare at 12/20:03 UTC.
Weekly geosynchronous satellite environment summary – Week beginning June 09, 2014. Image credit: SWPC
No proton events were observed at geosynchronous orbit although the greater than 10 MeV proton flux became slightly enhanced (flux values remained below 1 pfu) early on June 13, likely associated with the M3 flare from Region 2085 at 12/22:16 UTC.
The greater than 2 MeV electron flux at geosynchronous orbit was at normal to moderate levels over the past week and reached a maximum flux value of 227 pfu on June 13 at 14:05 UTC.
Geomagnetic field activity was predominately quiet with isolated periods of unsettled conditions on June 11 and 14.
Data by SWPC
Featured image: NASA SDO AIA 304 on June 10, 2014 @ 11:42 UTC. Edit: TW
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