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We explore the possible observational signatures of different types of kinkmodes (horizontal and vertical oscillations in their fundamental mode andsecond harmonic) that may arise in coronal loops, with the aim of determininghow well the individual modes can be uniquely identified from time series ofimages. A simple, purely geometrical model is constructed to describe thedifferent types of kink-mode oscillations. These are then `observed' from agiven direction. In particular, we employ the 3D geometrical parameters of 14TRACE loops of transverse oscillations to try to identify the correct observedwave mode. We find that for many combinations of viewing and loop geometry itis not straightforward to distinguish between at least two types of kink modesjust using time series of images. We also considered Doppler signatures andfind that these can help obtain unique identifications of the oscillation modeswhen employed in combination with imaging. We then compare the modeled spatialsignatures with the observations of 14 TRACE loops. We find that out of threeoscillations previously identified as fundamental horizontal mode oscillations,two cases appear to be fundamental vertical mode oscillations (but possiblycombined with the fundamental horizontal mode), and one case appears to be acombination of the fundamental vertical and horizontal modes, while in threecases it is not possible to clearly distinguish between the fundamental modeand the second-harmonic of the horizontal oscillation. In five other cases itis not possible to clearly distinguish between a fundamental horizontal modeand the second-harmonic of a vertical mode.

Identification of different types of kink modes in coronal loops: principles and application to TRACE results