SOUTHAMPTON OCEANOGRAPHY CENTRE

SOC to study rapid climate change
Professor Jochem Marotzke of the Southampton Oceanography Centre is to lead a six-year project recording changes taking place in the Atlantic. The research is funded by the UK Natural Environment Research Council as part of the RAPID Climate Change Programme.

It is reported that there are concerns that an increase in global warming could have knock-on effects on the stability of the climate in the North Atlantic - paradoxically making the region much colder. In as little as 20 years the climate in northern Europe could be some 5°C cooler. If UK temperatures dropped by 5°, the climate would be similar to that of Iceland. The project will set up a chain of moorings across the Atlantic that will monitor changes in strength and temperature of ocean currents. Positioned at latitude 25° north, off the coasts of Florida and Africa, monitors will provide profiles from just below the sea surface to the ocean floor at 5,000m. At present warm Atlantic water is pulled northwards towards the arctic, releasing heat into the atmosphere and ensuring that land masses such as Europe are considerably warmer than countries at similar latitudes around the Pacific. Near the Arctic this colder, denser water sinks and makes the return journey south, close to the Atlantic seafloor. The resulting current system is known as the Conveyor Belt.

Marotzke is a modeller of international status. He fears that in a warmer world, rainfall would increase and this extra fresh water could disrupt deep-sea convection. Fresh water could act like a lid to inhibit the release of heat and reduce the amount of warm water transported northwards. Maybe even stopping the Conveyor Belt. A key question is the depth at which the cold water returns. This information will then be used in computer models to provide a series of different scenarios.

Other SOC scientists have also been awarded funding for research into other aspects of rapid climate change. Dr Sheldon Bacon will be looking at millennial thermohaline circulation variability. Professor Harry Bryden is extending the time series of Atlantic Meridional Overturning backwards in time using historical measurements. Peter Challenor will be assessing the probability of rapid climate change. Simon Josey is looking at the role of air-sea forcing in causing rapid changes in the North Atlantic thermohaline circulation and Dr Neil Wells will be determining heat transfer and storage and their changes in the North Atlantic thermohaline circulation.