On the sensitivity of the generalised linear Rossby wave theory to uncertainties in the determination of the background mean flow: updated results
Event: 2014 Ocean Surface Topography Science Team Meeting
Session: Science Results from Satellite Altimetry: Finer scale ocean processes (mesoscale and coastal)
Presentation type: Type Poster
Contribution: not provided
This paper is an update on research presented at OSTST in 2013. Our new results confirm that the error in Killworth and Blundell (2003) theory identified in Tailleux (2012) dramatically affects the nature of the theoretical dispersion relation at high wavenumbers, but on the cases considered, the differences occur in a part of the wavenumber space that is not observable. In the 11 case studies examined, generally neither the time nor the longitudinal variations of the zonal mean velocity appear to affect inferences based on the temporal mean at the central longitude of the domain considered. Additionally, the standard deviation in the region considered appears to be very large compared to the mean zonal velocity, casting doubt on the validity of the linear approximation. In regions dominated by westward propagating eddies,the eddies can also contribute to the definition of the zonal mean velocity, raising the question of the correct theoretical approach to studying linear Rossby waves. This study confirms that for wavelengths below the Rossby radius, theoretical dispersion relations appear to be relatively insensitive to variations in the mean flow.