The upper 700 metres of the global ocean has seen a rise in temperature since reliable records began in the late 1960s. However, there has been a pause in this warming during the period from 2003 to 2010. The papers published this week offer explanations for this.

Climate model simulations from KNMI show that such pauses in upper ocean warming occur regularly as part of the climate system’s natural variability.

This is because of two factors. Firstly variations in the El Niño – Southern Oscillation, known as ENSO (a climate cycle which affects sea surface temperatures in the Pacific Ocean), cause more of the heat stored in the upper ocean to be released into space.

http://www.metoffice.gov.uk/news/releases/archive/2011/ocean-warming

Then they explain their theory that warm water sinks.

Secondly, heat can be temporarily moved to the deeper ocean below 700m due to changes in the Atlantic Meridional Overturning Circulation – the oceanic conveyor belt that transports vast amounts of heat in the North Atlantic Ocean.

h/t to Marc Morano