Thirty Years of GOSHIP and WOCE Data: Atlantic Overturning of Mass, Heat, and Freshwater Transport

Abstract

The Atlantic Meridional Overturning Circulation (AMOC) plays a vital role in global climate, redistributing heat, and freshwater. It is predicted to decline due to anthropogenic climate change, with major implications for global climate. Accurately assessing AMOC strength with in situ observations has inspired a number of dedicated observing systems in the Atlantic since the 2000s. However, no consensus has been reached on whether the slowdown of the AMOC and its associated heat and freshwater transports is occurring. These dedicated systems are too recent to detect long-term trends. We have analyzed hydrographic data from zonal sections across the Atlantic for 30 years that predate and overlap the era of AMOC observations. Our results show no changes in the AMOC for all sections analyzed over the whole Atlantic for the last 30 years. We also find an increased export of freshwater from the South Atlantic associated with an increase in upper salinity.