Reconciling the meridional connectivity of the MOC from observations

Efforts to monitor the ocean meridional overturning circulation (MOC) come at great expense. The observing array at 26N has now been making full-depth estimates of this ocean circulation since 2004. This time series of the MOC transports has informed our understanding of the ocean circulation variability on timescales of days to years, and is a benchmark for ocean numerical models. Yet estimates of the overturning at 16N show a 10-year trend of the opposite sign to the transports at 26N. How representative of the basinwide overturning circulation are the RAPID 26N observations at an individual latitude? Here I will discuss the use of satellite data (i.e., altimetry and GRACE) to estimate subsurface ocean transports, with a focus on the North Atlantic. By using satellite data, which span the entire North Atlantic basin, we can investigate the basin wide ocean circulation. I will introduce the method, compare satellite-based transport estimates to in situ observations, and illustrate how the satellite-derived transport estimates enhance our understanding of the ocean circulation variability and its response to atmospheric forcing.