Document Type
Article
Publication Title
The Astrophysical Journal
Abstract
Minimal observational evidence exists for fast transition region (TR) upflows in the presence of cool loops. Observations of such occurrences challenge notions of standard solar atmospheric heating models as well as their description of bright TR emission. Using the EUV Imaging Spectrometer on boardHinode, we observe fast upflows (vλ −10 km s−1) over multiple TR temperatures (5.8 logT 6.0) at the footpoint sites of a cool loop (logT 6.0). Prior to cool loop energizing, asymmetric flows of + 5 km s−1 and −60 km s−1 are observed at footpoint sites. These flows, speeds, and patterns occur simultaneously with both magnetic flux cancellation (at the site of upflows only) derived from the Solar Dynamics Observatory’s Helioseismic Magnetic Imager’s line-of-sight magnetogram images, and a 30% mass influx at coronal heights. The incurred non-equilibrium structure of the cool loop leads to a catastrophic cooling event, with subsequent plasma evaporation indicating that the TR is the heating site. From the magnetic flux evolution, we conclude that magnetic reconnection between the footpoint and background field is responsible for the observed fast TR plasma upflows.
DOI
10.1088/0004-637X/778/2/90
Publication Date
12-1-2013
Recommended Citation
Orange, Norton B.; Chesney, David L.; Oluseyi, Hakeem M.; Hesterly, Katie; Patel, M; and Champey, Patrick, "Direct Observations Of Plasma Upflows And Condensation In A Catastrophically Cooling Solar Transition Region Loop" (2013). Aerospace, Physics, and Space Science Faculty Publications. 294.
https://repository.fit.edu/apss_faculty/294