快猫短视频

THE sea around Antarctica is warming twice as fast as the rest of the world鈥檚
oceans, raising fears of a catastrophe in the region. 鈥淚f the Southern Ocean is
warming that quickly, the consequences are likely to be profound,鈥� says Mike
Meredith, an oceanographer at the British Antarctic Survey in Cambridge.

Traditionally, the Antarctic鈥檚 Southern Ocean has always been difficult to
study because of its isolation and severe weather. 鈥淚t鈥檚 a miserable place to go
to sea,鈥� says Sarah Gille, from the Scripps Institution of Oceanography in San
Diego, who has come up with the first clear picture of temperature changes
there.

Since 1990, researchers have released large numbers of robotic buoys which
send back data via satellite. To work out how the temperature has changed, Gille
had to combine this data with measurements taken from ships since the 1930s.

The results are a shock. The temperature 700 to 1100 metres down rose by 0.17
掳C between the 1950s and 80s, almost twice as much as the global oceans as a
whole. 鈥淭hat doesn鈥檛 sound like much but keep in mind that at these depths we
normally think the ocean is isolated from changes on the surface,鈥� she says.
Just how the deeper water could heat up so quickly is a mystery.

If the warm water melts sea ice, that would adversely affect the algae that
usually grow on its underside. Algae are an important food source for krill
which, in turn, are food for larger fish and mammals. 鈥淭he entire ecosystem
could be damaged,鈥� says Meredith.

Another worry is that any warming could reduce the Southern Ocean鈥檚 storage
capacity for huge volumes of dissolved carbon dioxide. That could lead to an
increase in carbon dioxide in the atmosphere and greater global warming.

Meredith says we鈥檒l need to work hard to understand the warming and its
effects. 鈥淚t鈥檚 very difficult to know exactly what will happen but it certainly
deserves further investigation.鈥�