Floating computers fight climate change

This diagram shows how the Argo float works.

Each float weights 25kg, is two metres in height (including its aerial) and costs around £15,000 to operate over its lifetime.

The floats normally drift at depths of 2,000 metres or 1,000 metres but, every 10 days, the bladder in the float fills with water, making it rise to the surface so that it can send its data to the various research centres via satellite.

After between six and 12 hours, the float then descends back to its operational depth. Each float is designed to repeat this cycle around 150 times during its lifetime.

The information is transmitted to various satellites then distributed around the world. The standard satellites can locate the floats to within 100 metres of their position.

The Argo programme also uses the US GPS satellites Iridium and Orbcomm, which allow more detailed data to be transmitted over a shorter period of time.

Credit: UCSD