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D.A. Falconer (UAH/MSFC), R.L. Moore, J.G. Porter, D.H. Hathaway (NASA/MSFC)
In either Fe IX/X images of Fe XII images from SOHO/EIT, the quiet solar corona shows structure on scales ranging from sub-supergranular (i.e., bright points and coronal network) to multi-supergranular (large-scale corona). In Falconer et al 1998 (Ap.J., 501, 386) we suppressed the large-scale corona and found that the network-scale coronal features are predominantly rooted in the magnetic network lanes at the boundaries of the supergranules. Here we investigate the relationship between the large-scale corona and the network as seen in three different EIT filters (He II, Fe IX/X, and Fe XII), and in the magnetic field from SOHO/MDI. We find that, underlying the brighter regions of the large-scale corona (either Fe IX/X or Fe XII), the coronal network (Fe IX/X, and Fe XII), the transition region network (He II), and the magnetic flux content of the network are all enhanced relative to that underlying the dimmer regions of the large-scale corona. We find that the transition region network radiates more than the large-scale corona, which radiates more than the coronal network. From our results we infer that quiet-sun regions (supergranular or larger in size) with enhanced magnetic flux produce enhanced network activity. The small fraction of the network activity manifested as coronal network also increases with increasing magnetic flux. The network activity, predominately the transition region network activity, (or something else also correlated with the magnetic field) drives the heating of the large-scale corona. If the large-scale corona is being heated by the transition region activity, the heating must be done primarily by some nonthermal process (nonjet, possibly waves or currents), because the transition region is cool relative to the corona. This work was funded by the Solar Physics Branch of NASA's office of Space Science through the SR&T Program and the SEC Guest Investigator Program.
The author(s) of this abstract have provided an email address for comments about the abstract: david.falconer@msfc.nasa.gov