Transition region and coronal structuring

In this paper we examine regions of internetwork, network and bright networ k emission, observed in the quiet Sun with the Coronal Diagnostic Spectrome ter (CDS) onboard SoHO. The slopes of the emission measure distributions, b etween 5.4 less than or equal to log T-e less than or equal to 6.0, are fou nd to differ in each region, suggesting the presence of different atmospher ic structures. From an analysis of emission area the network is shown to ha ve two populations of structures, a low transition region group and a coron al group. Using MDI magnetograms the bright network emission is shown to or iginate from regions of strong magnetic field composed of bipolar loops and unipolar funnels, that extend from the low transition region up to the cor ona. Up to 30% of all radiative losses between 5.7 less than or equal to lo g T-e less than or equal to 6.3 are found to come from these continuous bri ght network structures. Cross-sectional areas calculated from redshift valu es suggest that the area expansion seen in the bright network emission is t he result of flux tube expansion into the corona, accompanied by either a d ownflow or upflow of material.