Observation and Modeling of the Solar Transition Region. II. Identification of New Classes of Solutions of Coronal Loop Models

In the present work we undertake a study of the quasi-static loop model andthe observational consequences of the various solutions found. We obtain themost general solutions consistent with certain initial conditions. Great careis exercised in choosing these conditions to be physically plausible (motivatedby observations). We show that the assumptions of previous quasi-static loopmodels, such as the models of Rosner, Tucker and Vaiana (1978) and Veseckey,Antiochos and Underwood (1979), are not necessarily valid for small loops attransition region temperatures. We find three general classes of solutions forthe quasi-static loop model, which we denote, radiation dominated loops,conduction dominated loops and classical loops. These solutions are thencompared with observations. Departures from the classical scaling law of RTVare found for the solutions obtained. It is shown that loops of the type thatwe model here can make a significant contribution to lower transition regionemission via thermal conduction from the upper transition region.Comment: 30 pages, 3 figures, Submitted to ApJ, Microsoft Word File 6.0/9