Persistent acceleration in global sea-level rise since the 1960s

• Published in: Nature Climate Change
• Main Authors: Dangendorf, Sönke, Hay, Carling, Mir Calafat, Francisco, Marcos, Marta, Piecuch, Christopher G., Berk, Kevin, Jensen, Jürgen
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: Southern Ocean; Pacific
• Online Access: http://nora.nerc.ac.uk/id/eprint/525251/; https://nora.nerc.ac.uk/id/eprint/525251/1/s41558-019-0531-8.pdf; https://doi.org/10.1038/s41558-019-0531-8

Previous studies reconstructed twentieth-century global mean sea level (GMSL) from sparse tide-gauge records to understand whether the recent high rates obtained from satellite altimetry are part of a longer-term acceleration. However, these analyses used techniques that can only accurately capture either the trend or the variability in GMSL, but not both. Here we present an improved hybrid sea-level reconstruction during 1900–2015 that combines previous techniques at time scales where they perform best. We find a persistent acceleration in GMSL since the 1960s and demonstrate that this is largely (~76%) associated with sea-level changes in the Indo-Pacific and South Atlantic. We show that the initiation of the acceleration in the 1960s is tightly linked to an intensification and a basin-scale equatorward shift of Southern Hemispheric westerlies, leading to increased ocean heat uptake, and hence greater rates of GMSL rise, through changes in the circulation of the Southern Ocean.