Solar Arcades as Possible Minimum Dissipative Relaxed States

Abstract

In this work, arcade structures are modeled to be in minimum dissipative relaxed states using a two-fluid description of the plasma. The obtained relaxed state is non-force-free in nature and appropriate to an open system with external drives. The Euler - Lagrange equations are solved in Cartesian coordinates subject to the appropriate photospheric boundary conditions. The solutions are seen to support flow-containing arcade-like magnetic field configurations with inherent dissipative properties that may play an important role in coronal heating. An interesting feature observed is the generation of different types of arcades with the variation of a single parameter characterizing the relaxed state. Also, observations with the LASCO coronagraph on board the SOHO spacecraft suggest that helmet streamers originating from the Sun may have an internal triple-arcade structure. The two-fluid relaxed state obtained here is also seen to support such structures.