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Observation of Sigmoids with Solar-B. K.Hori (Hiraiso Solar Observatory, CRL). Sigmoids Classification. After Pevtsov 2002. Interlocking Loops (Eruptive). Multiple Loops. Single Loop. (Eruptive). Inter-Region Sigmoid. Secrets of Sigmoids.
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Observation of Sigmoids with Solar-B K.Hori (Hiraiso Solar Observatory, CRL)
Sigmoids Classification After Pevtsov 2002 Interlocking Loops (Eruptive) Multiple Loops Single Loop (Eruptive) Inter-Region Sigmoid
Secrets of Sigmoids - Magnetic topology (e.g., helicity, shear buildup) Priest 1992; Titov et al.1993; Rust&Kumar 1996; Demoulin et al. 1997; Amari et al. 2000…. - Connection with Eruptions (e.g., missing mass deduced from dimming, CMEs) Hudson&Webb 1997; Sterling&Hudson1997 Canfield et al. 2000; Glover et al. 2000…. - Formation and Evolution of Sigmoids Sigmoid→Arcade/Cusp Physical process involved in the formation of sigmoids is still not clear.
By linkage of two initially unconnected bipoles/ARs? Martens & Zwaan 2001 Formation of Sigmoids By emerging below the photosphere as a part of a twisted flux tube? Matsumoto et al. 1998; Magara and Longcope 2001,…
18-Oct-1994 Temperature Diagnosis of Interlocking Sigmoids
19-Oct-1994 Goes M3 Moore et al. 2001 Case1: AR Sigmoid SXT Al1+AlMg 19:00:20-19:34:10 20:32:12-20:49:36 20:50:08-20:53:28 Flare Early in the rise phase (MK)
Case2: AR Sigmoid 25-Oct-1994, C4.7 Manoharan et al.1996 van Driel-Gesztelyi et al. 2000 SXT Al1+AlMg 09:47:09-09:50:21 10:00:39-10:03:55 11:28:55-11:32:11 Short Loops (MK)
Case3: Sigmoidal Filament 8-May-2000 B6.8 Yohkoh SXT 17GHz (NoRH) Hα May 7 Hiraiso 5 10 km May 8 Hida, FMT 04:35 04:00 04:26
17GHz dark patch: Manifestation of low temperature regions (Tb < 10 K ) 4 May 7 May 8 04:26:25 05:09:05 Heating has started. The midpoint remained to be cold.
04:58:00 05:10:00 05:36:00 Sigmoid Evolution in Hα • Bifurcation and disappearance of the eastern half of the filament. • B6.8 Two-ribbon flare 08:09:31 SXT
Magnetic Structure of Interlocking Sigmoids = + ? ?
Yohkoh SXTwas the best observational tool to reveal the secrets of Sigmoids if..... • the observations were not interrupted so often by Yohkoh nights. • the SXR brightness of flare regions were notsaturated. →Exposure time, temperature range • velocity and magnetic field maps could be obtained simultaneously with temperature and EM maps. →XRT,SOT,EIS