An Analysis of A Tornado-Like Prominence Observed by SDO

Abstract:

We studied a tornado-like prominence near the Northwest limb, observed on 2014 November 1 by the Atmospheric Imaging Assembly (AIA) onboard Solar Dynamic Observatory (SDO). Starting at 02:00 UT, the prominence began to rise slowly. About two hours later, we observed tornado-like horizontal motions as high as 150 Mm above the limb, which were associated with the heating of the dark prominence into brightening material in AIA 17.1 nm. Interactions between the prominence and the overlying coronal loops resulted in the downflows of the prominence material along the loops back to the solar surface, with the landing sites of the downflowing material moving sequentially away from the prominence channel. This could result from magnetic reconnections between the prominence field and the overlying field, which proceeded to higher and higher altitudes when the reconnections encroached into the overlying field. Helical motions at low altitudes are interpreted as flows along the twisted field that supported the prominence against the gravity in its quiescent state. A localized flux emergence within a nearby active region is considered as the trigger the tornado.