| 其他摘要 | Solar small-scale activities are ubiquitous over quiet-Sun region and coronal hole. Smaller eruptive events and finer structures are studied because of the development of solar observation from both ground-based and space-borne instruments. By means of multi-angle and multi-wavelength observations from SDO and STEREO spacecraft, this thesis focuses on kinds of small-scale activities associated with minifilament eruptions. The so-called mini coronal mass ejections (CMEs) were recently identified as small-scale eruptive events showing the same on-disk characteristics as largescale CMEs, and Moore et al. 2010 further found that one-third of polar X-ray jets are the so-called blowout jets, in which the jet-base magnetic arch, often carrying a filament, undergoes a miniature version of the blowout eruptions that produce major CMEs. By means of the two viewpoint observations from SDO and STEREO-A, I present the first observations that a blowout jet from the eruption of an EUV mini-filament channel in the quiet Sun was indeed associated with a real micro-CME. Captured by the on-disk SDO observations, the whole life of the mini-filament channel, from the formation to eruption, was associated with convergences and cancellations of opposite-polarity magnetic flux in the photosphere, and its eruption was accompanied by a small flare-like brightening, a small corona dimming, and posteruptive loops. The near-limb counterpart of the eruption observed by STEREO-A, however, showed up as a small EUV jet followed by a white-light jet. These observations not only confirm the previous results that mini-filaments have characteristics common to large-scale ones, but also give clear evidences that blowout jets can result from the eruptions of minifilaments and are associated with mini-CME. It is well known that some coronal jets exhibit helical structures and untwisting. I attempt to inspect the origin of twist in a blowout jet. By analyzing observations with multiple viewpoints from SDO and STEREO-A, a polar untwisting jet is identified as a blowout EUV jet that comes from the eruption of a prominence. In the SDO views, the small jet exhibits untwisting behavior in 30.4 nm and two jet-spires in 17.1 nm. By tracking a bright feature moving helically in the jet, I find that the jet untwists itself in a period of 475 s with a rotational speed of 0.76 degree per second, and is ejected upward at an approximately constant velocity(about 108 km per sec). Considering that the blowout jet untwists in about 7 min, we also estimated thatthe twist completes about 0.89 turns. STEREO observations further suggest that the blowout jet is indeed a whiplike prominence eruption and leads to a white-light jet. Blowout jets associated with micro CMEs have already been reported in several observations It is necessary to inspect a general relationship between blowout jets and micro-CME events. Coronal bright points (CBPs) are small-scale, long-lived coronal brightenings that always correspond to photospheric network magnetic features of opposite polarity. I adopt 30 bright points with lifetime ranging from 5 h to 35 h in a coronal hole on solar disk to study their eruptive behavior using data from AIA and HMI onboard SDO. About one quarter to one third of the CBPs in the coronal hole go through miniature filament eruptions one or more throughout their lifetime. The filament eruptions occur in temporal association with the brightness maxima of CBPs and are strong related to convergence and cancelation of underlying magnetic dipoles. These new observations also indicate that CBPs are more complex in dynamical evolution and magnetic structure than previously thought. I analyzed a small-scale jet observed on April, 22, 2011 in a solar quiet region, using data from SDO/AIA, HMI, with supplemental data from STEREO/EUVI. From HMI magnetograms and calculated photospheric flows, I find that the jet is related |
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