Gliders

Scottish Association for Marine Science

Eyes on the Atlantic

SAMS has operated gliders in the north-east Atlantic since 2010 but has had near continuous glider data collection for the past 10 years. Over that time, the gliders have been on more than 30 missions, travelling more than a combined 65,000 kilometres.

This continuity is giving scientists new insights into ocean properties such as temperature, salinity and oxygen and is also helping us better understand how huge ocean currents move.

Satellites are extremely effective at measuring the sea surface over a large area and fixed mooring sensors can give a more detailed picture, but even the shallowest of these are at 50 metres’ depth and are fixed in one place. Gliders are able to fill in the gaps.

SAMS gliders continually monitor the north-east Atlantic, where the exchange between the salty and relatively warm Atlantic water and the colder, fresher Arctic Ocean plays a major role in global climate.

A large system of ocean currents, known as the Atlantic Meridional Overturning Circulation (AMOC) transports warm surface waters from the tropics northward towards the subpolar and Arctic regions. There, the waters cool, become denser and sink before returning southward at depth. In doing so, this vast ‘conveyor belt’ movement of water is a major factor in controlling global heat distribution, regional sea level changes, the ocean’s absorption of carbon and European weather.

SAMS oceanographer Prof. Stuart Cunningham said: “We are very interested to find out what the effects of a warming ocean will have on the AMOC. Often described as Europe’s central heating system, it relies on the water being much cooler in the global north. If the water is too warm, this can inhibit the dense water formation which drives the AMOC, and that could have profound effects on global climate and weather.”