Magnetohydrodynamic continua and stratification induced Alfven eigenmodes in coronal magnetic loops

The continuous spectra of a 2D inhomogeneous, cylindrical magnetic flux tube are studied and applied to solar coronal loops. The density is stratified radially as well as longitudinally, while other equilibrium quantities only vary in the radial direction. Stratification causes gaps to appear in the continuous spectrum, and it is shown that discrete global, stratification-induced Alfven eigenmodes occur in these gaps. These global modes may be important for the heating of coronal loops.