MAGNETIC FINE-STRUCTURES IN CORONAL LOOPS

The formation of magnetic fine structures and associated electric curr ents is considered in the context of the coronal heating problem. The penetration of field-aligned electric currents into the lower atmosphe re is discussed. It is argued that currents strong enough to heat the corona can persist only for short periods of time. The formation of th in currents sheets is discussed. It is argued that photospheric magnet ic structures (flux tubes) play an important role in the generation of coronal currents.