Publication
Characteristics and Trends of the Campbell Plateau Meander in the Southern Ocean: 1993-2020
Publisher:
Authorea, Inc.
Date:
16-04-2023
DOI:
10.22541/ESSOAR.168167195.52432016/V1
Abstract: Meanders are significant features of the Antarctic Circumpolar Current in the Southern Ocean and sites of enhanced upwelling, cross-frontal tracer fluxes, and exchanges between the surface and deep ocean. They usually overlap the locations of fronts and are linked to topographic features. While much is known about Southern Ocean fronts and how they are changing, the response of meanders to climate change is largely unexplored. In this study, we investigate the C bell Plateau meander south of New Zealand. We apply a local gradient maxima method to satellite altimetry data to identify the position of the meander and estimate its width, geostrophic current speed and associated trends over the 1993-2020 period. We find that the position of the meander has been relatively fixed, except for the section downstream from the Plateau, which has shifted northward by about 0.4° latitude per decade. The meander has become flatter at the Plateau’s western edge, but steeper at the eastern edge of the Plateau. Overall, the meander has been widening by 2 km per decade and accelerating by 0.01 m s-1 per decade, particularly downstream from the Plateau. These findings are consistent with other work on standing meanders and observed changes in the Southern Ocean. While we cannot attribute the observed trends of the C bell Plateau meander to one particular forcing mechanism, we discuss several hypotheses in the context of existing literature. Whether these trends are similar for other Southern Ocean meanders and their implications remains to be verified.