Variability, coherence and forcing mechanisms in the New Zealand ocean boundary currents

Progress in Oceanography (2018)

NB: Closed access article

Using over 20 years of satellite altimeter observations and in situ data, we investigate the mean and variability of the South Pacific’s western boundary current transports at seasonal, interannual and decadal time scales. We relate the means and fluctuations of the currents to the Southern Oscillation Index and to potential drivers of the circulation, including local and basin-scale winds. We find the currents are highly variable and there are no discernible trends in the transports since 1993. There is little coherence between transports along the boundary, suggesting a range of mechanisms drive the variability of the currents individually.