On a Surge: Properties of an Emerging Flux Region
On a Surge: Properties of an Emerging Flux Region
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DOI：
10.1086/421715
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发表时间：
2004-08
期刊：
影响因子：
--
通讯作者：
Yu Liu;H. Kurokawa
中科院分区：
文献类型：
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作者：
Yu Liu;H. Kurokawa
提出了使用多仪器和多波长观测的浪涌事件。该事件发生在2001年8月30日的一个浪涌产生区。TRACE白光图像、怀柔矢量磁图和Hβ滤波图显示，这次浪涌与1小时内出现的新双极子密切相关。在浪涌的足点处揭示了磁抵消增强的证据，其中 Hβ 线中显示了同时的浪涌耀斑。特别是，这次激增的有趣观测结果是：（1）这次激增与新兴斑点附近明显的光球亮点有关； (2)在矢量磁图中，在涌流上升期间，在涌流底部出现的通量和周围场之间出现了可靠的横向场，这些新鲜的横向场在20分钟后消失； (3)当浪涌活动停止时，白光图像中出现的双极子的先前斑点几乎消失； (4) TRACE UV (1550 Å) 通道显示亮浪涌 (~105 K) 与暗 Hβ 浪涌 (~103-104 K) 密切相关。紫外线浪涌呈明亮的尖峰形状，并沿着Hβ浪涌的外缘喷出。同样，TRACE EUV (~106 K) 中的明亮成分也位于 Hβ 浪涌的边缘。 SOHO/EIT 和 Yohkoh/SXT 的观测结果都表明，喷射等离子体是从浪涌期间发现的耀斑日冕环的一个足点喷射出来的。我们估计了SXR中磁抵消位置释放的磁能、浪涌的动能和环路增亮的热能，发现磁重联可以为浪涌活动和日冕环路加热提供足够的能量。对于这种激增，多波长（Hβ、白光、UV、EUV 和 SXR）中的所有相关现象都具有良好的时间和空间关系。这些事实支持磁重联模型，其中浪涌起源于低层大气。此外，低空磁重联可能导致在光球层上观察到的磁抵消。
A surge event with multi-instrument and multiwavelength observations is presented. The event occurred in a surge-productive region on 2001 August 30. TRACE white-light images, Huairou vector magnetograms, and Hβ filtergrams show that this surge was closely associated with new bipoles that emerged in 1 hr. Evidence of enhanced magnetic cancellation is revealed at the footpoints of the surge where a simultaneous surge flare is shown in the Hβ line. In particular, the interesting observational results for this surge are that (1) the surge was associated with pronounced photospheric bright points near the emerging spots; (2) in vector magnetograms, during the surge ascending period, reliable transverse fields appeared between the emerging flux and the ambient fields cancelled at the base of the surge, and these fresh transverse fields disappeared after 20 minutes; (3) the preceding spots of the emerged bipoles almost disappeared in white-light images when the surge activity stopped; and (4) the TRACE UV (1550 Å) channel showed a bright surge (~105 K) well correlated with the dark Hβ surge (~103-104 K). The UV surge had a bright spike shape and spouted out along the outer edges of the Hβ surge. Similarly, the bright components in TRACE EUV (~106 K) were also located at the edges of the Hβ surge. Both the SOHO/EIT and Yohkoh/SXT observations demonstrate that the jet plasma was ejected from one footpoint of a flaring coronal loop identified during the surge. We estimate the magnetic energy released from the site of the magnetic cancellation, the kinetic energy of the surge, and the thermal energy for the loop brightening in SXR, finding that the magnetic reconnection could supply enough energy for the surge activities and the coronal loop heating. For this surge, all the correlated phenomena in multiwavelengths (Hβ, white light, UV, EUV, and SXR) are in good temporal and spatial relationship. These facts support a magnetic reconnection model in which surges originate in the low atmosphere. Moreover, low-altitude magnetic reconnections can result in the magnetic cancellation observed on the photosphere.