Talk abstract details

Spatial maps of the high-pass frequency filtered time-averaged root-mean-squared (RMS) Doppler velocities tend to show substantial decrements within regions of strong field and curiously, randomly distributed patches of enhancement in the vicinity. We propose that these haloes or enhancements are a consequence of magnetic-field-induced mode mixing (scattering), resulting in the preferential powering of waves that possess strong surface velocity signatures (i.e. scattering from low to high wavenumbers). With increasing frequency and consequently, decreasing wavelength, a growing number of modes are scattered by the field, thereby rendering the enhancements most visible around the high-frequency parts of the spectrum. We present compelling observational evidence in support of this theory. The implications of this thesis are (1) it is unlikely that wave power enhancements are due to field-induced locally anomalous turbulent wave excitation (a previous hypothesis) and (2) we may utilize the scattering properties to constrain properties of the field (i.e. the S matrix approach).