615 / 2024-09-18 16:32:53

Observed interannual variability in the subtropical AMOC during 1993-2020

AMOC, sea surface height,interannual variability

As a key element in the global climate system, the Atlantic meridional overturning circulation (AMOC) can redistribute heat, salt and other biochemical components throughout the ocean. However, there are only a few ongoing AMOC observations at limited latitudes and for a relatively short time span. To address this, we use satellite and cable observations to reconstruct the subtropical AMOC time series for 1993 – 2020. Our results reveal that the sea surface height can effectively represent the interannual variability in the upper mid-ocean geostrophic transport. Our reconstruction, combined with the Gulf Stream from the cable observation and the Ekman transport from the sea surface wind, reflects the subtropical AMOC interannual variability during 1993-2020 (±2 Sv). Potential impacts from the winds to the observed AMOC interannual variability and the sources of AMOC low frequency variability will be discussed.