| Presentation Title: | Unresolved Fine Structure and the Conductive Transition Region |
| Author(s): | Shane Atwood
Charles Kankelborg |
Abstract:
Transition region (TR) emission below 100,000 K is brighter than can be explained by heat conduction alone, with brightness increasing as temperature declines. Consequently, the ratio of C II (formed around 20,000 K) emission to Si IV (about 80,000 K) is brighter than expected. We employ large, dense, 400-step IRIS rasters on 7 quiet sun (QS) observations to obtain statistics on emission in these lines. In all observations, we find widespread, bright C II emission even where there is little or no Si IV. There is a near-linear average trend in C II intensity as a function of Si IV, but this trend very clearly passes above the origin. We interpret the data as a two-component atmosphere: a sparse, classical TR anchors coronal structures among a cool background dominated by unresolved fine structure.