Dynamics of coronal loop oscillations

We will discuss the observed, heavily damped transversal oscillations of coronal loops. These oscillations are often modeled as transversal kink oscillations in a cylinder. Several features are added to the classical cylindrical model. In our models we include loop curvature, longitudinal density stratification and highly inhomogeneous radial density profiles. We investigate the effect of vertical density stratification both numerically and analytically. We can conclude that longitudinal stratification establishes a coupling between different longitudinal mode numbers. On the other hand, the observational parameter τdamping/Period is not in-fluenced. However, since the ratio of periods of different longitudinal numbers is different from 2, we can estimate the density stratification in a loop if two longitudinal mode numbers are observed. We can conclude that the inclusion of vertical density stratification provides an excellent tool for coronal seismology. Additionally, we analyze a theoretical model for curved coronal loops. Because of the curvature, poloidal mode numbers are coupled. In the small curvature limit, however, only coupling to the two neighbouring poloidal mode numbers occurs. Expressions for the (complex) frequency are obtained.status: publishe