Figure: Mean steric height of the sea surface relative to 2000 decibars (black contours at 10cm intervals) shows the pattern of flow for the Argo era (2004-2012) based on Argo profile data, updated from Roemmich and Gilson (2009). The sea surface height (SSH) trend (cm per decade, colour shading) for the period 1993-2011 is based on the AVISO altimetry ‘reference’ product (Ducet et al., 2000). Spatial gradients in the SSH trend, divided by the (latitude-dependant) Coriolis parameter, are proportional to changes in surface geostrophic velocity. For display, the mean steric contours and SSH trends are spatially smoothed over 5 degrees longitude and 3 degrees latitude.
Reference: IPCC 5th Assessment Report, WG1 Chapter 3: Ocean Observations
Source (13/12/2017): http://rstb.royalsocietypublishing.org/content/367/1593/1245