Time series of global ocean heat content at different depths

This figure describes the change in global ocean heat content for the upper 700 m and the upper 2000 m of the ocean, both as annual average and as 5-year average. Ocean heat content is defined as the change in heat content of an ocean layer relative to a reference period (here: 1955 to 2006). The length of the time series differs depending on the ocean layer and the smoothing period.