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The May 1997 and May 1998 MURI events. George H. Fisher UC Berkeley. May 12 1997. Classic 2-ribbon flare occurring in NOAA AR 8038 at ~ 04:45 UT Halo CME seen ~ 1-2 hours later (partial) filament eruption Global solar magnetic configuration is quite simple
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The May 1997 and May 1998 MURI events George H. Fisher UC Berkeley
May 12 1997 • Classic 2-ribbon flare occurring in NOAA AR 8038 at ~ 04:45 UT • Halo CME seen ~ 1-2 hours later • (partial) filament eruption • Global solar magnetic configuration is quite simple • Magnetic data: poor temporal coverage, coarse spatial resolution • In MURI teams: Yang Liu (Stanford) is doing most of the work on this event
Global magnetic configuration around May 12, 1997 (pfss model) • Overall global magnetic configuration is simple; just one active region on the disk at the time of the flare/CME.
Magnetic Evolution of AR 8038 over 3 days: • Active region appears to be mature and starting to decay, with apparent flux cancellation…
May 12, 1997: Evolution seen in H • 2-ribbon flare • Partial filament disappearance • X-ray importance: C-class
May 12 1997: X-ray evolution: • Before flare: sigmoid shaped arcade • Flare decay: classic candle-flame shaped arcade
May 12, 1997: Double dimming, EIT wave • Double-dimming occurs after flare, roughly at ends of 2-ribbon flare arcades.
May 12 1997: LASCO C2 images • Wimpy halo event seen ~ 2 hours after the 2-ribbon flare
Interplanetary Data for the May 12 1997 event • Some hidden text
May 1, 1998 • Active region 8210 produced a long series of flares and CMEs as it rotated across the disk. Our focus is several small flares / CMEs occurring on May 1, 1998 because of very high quality vector magnetic field observations taken that day. • Overall solar configuration was not so simple: 8210 appears connected to an active region across the equator via trans-equatorial loops
Global magnetic configuration around May 1, 1998 (pfss model) • AR 8210 appears to be magnetically connected to a northern hemisphere AR and is also adjacent to a low-latitude coronal hole…
24 hours of high cadence MDI evolution of AR 8210 on May 1 1998: • Flux emergence above and to right of sunspot • Clockwise rotation of sunspot • Flow of positive polarity on left of spot toward lower right
H evolution of AR8210 on May 1, 1998 • There are several filaments associated with this active region, which appear to be constantly evolving • There appears to be a 2-ribbon flare around 23:40 UT
X-ray evolution of AR 8210 on May 1, 1998 • Note simultaneous flickering of the two active regions, plus hint of transequatorial loops • Note the repeated activation of the arcade of loops on the LHS of the active region
EIT evolution of AR 8210 on May 1, 1998 • Note repeated brightenings along LHS of active region adjacent to “coronal hole” • This evolution described by Sterling & Moore in their paper on EIT “crinkles” as repeated reconnection of closed field lines with open field lines in the hole