Studies of magnetic coupling in the solar atmosphere with observations at Canaries Islands coordinated with satellite observations

2005年7月3日至14日，利用安装在西班牙加那利群岛的太阳望远镜成功地对太阳表面进行了高空间分辨率光学观测。参与这次观测的望远镜及其焦平面仪器是：1）两台安装在特内里费岛德国真空塔望远镜上的可见光和红外线斯托克斯偏振计，2）拉帕尔马岛瑞典太阳望远镜的滤光成像仪，3）拉帕尔马岛荷兰开放望远镜的滤光成像仪。该观测是根据2005年被国际时间计划接受的观测计划（PI：Y.Katsukawa）进行的。为了监测日冕中的磁场结构和动力学，TRACE和SoHO卫星上的极紫外望远镜也同时对感兴趣的目标进行了观测，利用这些观测数据进行的研究提供了一些关于太阳大气中动力学和磁耦合的新知识。我们的发现之一是在太阳黑子护城河地区的小尺度光球事件与极端红移斯托克斯V信号。斯托克斯V信号的红移表明存在质量下降流，其速度为每秒10公里，超过了光球层的声速。活动的规模非常小，活动的持续时间不到1小时。红移的信号可以解释为在色球层上部或光球层下部发生的磁场重联的向下流动。

High spatial resolution optical observations of the solar surface was successfully performed using solar telescopes installed on the Canaries Islands, Spain on 3-14 July 2005. The telescopes and their focal plane instruments involved in this observation are : 1) two Stokes polarimeters at visible light and infrared, installed in the German Vacuum Tower Telescope at Tenerife, 2) filter imagers with Swedish Solar Telescope at La Palma, and 3) filter imagers with Dutch Open Telescope at La Palma. This observation was performed based on an observing proposal (PI: Y.Katsukawa) accepted as the International Time Program in 2005. To monitor magnetic-field structure and dynamics in the corona, the target of interest is also observed simultaneously by EUV telescopes onboard TRACE and SoHO satellites.Studies using the data from this observation have given some new knowledge on dynamics and magnetic coupling in the solar atmosphere. One of our finding is small-scale photospheric events with extremely red-shifted Stokes V signal in sunspot moat regions. The red-shift in Stokes V signal suggests the existence of mass downflows with 〜10 km/s, which exceeds a sound velocity at the photosphere. The size of the events is extremely small and the duration of events are less than 1 hour. The red-shifted signal can be interpreted as downward flow from magnetic reconnection occurring at the upper chromosphere or lower photosphere.