Measuring Europe’s central heating system

British scientists set sail today from Glasgow to begin work aimed at discovering if Britain is indeed in danger of entering the next ice age.

Scientists on the Royal Research Ship Discovery are on their way to deploy oceanographic instruments across the Atlantic Ocean from the Canary Islands to the Bahamas. The instruments will spend the next four years measuring the temperature, salinity and speed of currents.

The work is part of a research programme called Rapid Climate Change, funded by the UK’s Natural Environment Research Council and the USA’s National Science Foundation. This measurement programme across the Atlantic is being carried out by scientists from Southampton Oceanography Centre (SOC) and the University of Miami.

Dr Stuart Cunningham, of SOC, explained, “These specially developed instruments will be attached to wires up to 5000m metres long. The wires are anchored to the seabed and buoys at the top hold them straight just under the surface. Some instruments will motor up and down the wires every two days, taking measurements, for the next four years.

“We’re taking measurements at 22 moorings on the continental slope off Africa, either side of the mid Atlantic ridge, and on the continental slope of the USA.”

The measurements will help discover what, if anything, is going on with currents circulating in the Atlantic that act as Europe’s central heating system. Warm surface water is driven by the wind from the Gulf of Mexico north towards Europe. It moves fast, transporting heat equivalent to the power generated by one million nuclear power stations. The warm surface water gives its heat off to the atmosphere, which in turn keeps Europe about 5-10ºC warmer than it would otherwise be. In the seas around the Arctic it cools and sinks and returns south – the Atlantic overturning circulation.

Stuart said, “We know that in the past disruptions to this system of currents have coincided with rapid transitions in and out of ice ages.

“Now as the climate warms more ice is melting at the North Pole. This extra cold fresh water could halt the overturning circulation, stopping all this extra heat reaching Northern Europe. There is speculation that this could quickly plunge us into a mini ice age.

“This pilot scheme will monitor variations in the circulation. It might show the circulation is slowing down. It might be speeding up. We don’t know.”