Cold water gets mixed in ‘blender’ of Scotia Sea

The Scotia Sea, located between the Antarctic and the tip of South America, acts like a ‘blender’ on the very cold ocean waters that influence global ocean circulation patterns and ultimately climate, according to new research from the University of East Anglia (UEA) and published today (28 February) in the international journal Nature.

The research, carried out by Dr Karen Heywood, Dr David Stevens and Dr Alberto Naveira Garabato, shows that the dense, cold waters formed in the Weddell Sea near the Antarctic continent, and which provide the cold layers at the bottom of much of the world’s oceans, get mixed up in the Scotia Sea much more than previously thought, before they escape to the open waters of the South Atlantic.
“Previously we didn’t know where much of the cold water mixing took place. We’ve shown for the first time that the coldest water from the bottom of the Weddell Sea gets violently churned up as it passes through gaps in the ridge system found on the seabed in the Scotia Sea, mixing upwards towards the surface. This accounts for up to twenty percent of the water mass that cools the global ocean,” said Dr Heywood of UEA’s School of Environmental Sciences.

“We measured a range of factors including temperature, salinity and pressure of the water at 170 different points around the Scotia Sea and with the data we collected we have calculated the amount of mixing that takes place. These findings will help improve the accuracy of global climate models, which have ocean circulation patterns as a key factor,” said Dr Stevens of UEA’s School of Mathematics.

The research was carried out as part of the ALBATROSS project (Antarctic Large Scale Box Analysis and the Role of the Scotia Sea) which was designed to measure the flow of water into and out of the Scotia Sea in order to determine the role it plays in ocean circulation.

The findings are published today (28 February 2002) in the international scientific journal, Nature, in a paper entitled “High mixing rates in the abyssal Southern Ocean” (Nature, vol 415, 28 February 2002, pp1011-1014).