The Coldest, Deepest Ocean Water Mysteriously Disappears

The Coldest, Deepest Ocean Water Mysteriously Disappears

The coldest deep ocean water that flows around Antarctica has been mysteriously disappearing

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"In every oceanographic survey repeated around the Southern Ocean since about the 1980s, Antarctic Bottom Water has been shrinking at a similar mean rate, giving us confidence that this surprisingly large contraction is robust," Sarah Purkey

Sarah Purkey

In: Science on Msnbc.com

By: OurAmazingPlanet Staff

The coldest deep ocean water that flows around Antarctica in the Southern Ocean has been mysteriously disappearing at a high rate over the last few decades, scientists have found.

This mass of water is called Antarctic Bottom Water, which is formed in a few distinct locations around Antarctica, where seawater is cooled by the overlying air and made saltier by ice formation (which leaves the salt behind in the unfrozen water). The cold, salty water is denser than the water around it, causing it to sink to the sea floor where it spreads northward, filling most of the deep ocean around the world as it slowly mixes with warmer waters above it.

"In every oceanographic survey repeated around the Southern Ocean since about the 1980s, Antarctic Bottom Water has been shrinking at a similar mean rate, giving us confidence that this surprisingly large contraction is robust," said lead author of the study Sarah Purkey, a graduate student at the University of Washington in Seattle.

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"In every oceanographic survey repeated around the Southern Ocean since about the 1980s, Antarctic Bottom Water has been shrinking at a similar mean rate, giving us confidence that this surprisingly large contraction is robust," Sarah Purkey

Sarah Purkey