Archive by category | Ocean science

Indian Ocean: Gatekeeper to climate extremes?

Indian Ocean: Gatekeeper to climate extremes?

Some glacial periods in the Earth’s more recent geological past have been cooler and more severe than others, despite very similar greenhouse gas concentrations and orbital parameters. What is it that decouples global temperature from carbon dioxide levels and the solar heat?  Read more

AGU Chapman: Could seafloor vents control atmospheric CO2?

AGU Chapman: Could seafloor vents control atmospheric CO2?

As the Earth has alternated between glacial and inter-glacial periods, the steep climatic ups and downs have gone hand in hand with changes in atmospheric carbon dioxide levels. But where was the CO2 going to and coming from? Scientists have pointed to the ocean – currently a vast sponge for the greenhouse gas.  Read more

Atlantic Ocean circulation: the inside story

The system of surface and deep currents which make up the Atlantic Ocean circulation, a powerful heat conveyor belt and a poster child for abrupt climate change, is a more complex affair than straightforward textbook diagrams suggest.  Read more

Results cast doubt on potential ‘climate fix’

Results cast doubt on potential ‘climate fix’

Cross posted from The Great Beyond A controversial experiment which poured iron into the Southern Ocean has also poured cold water on the idea that such ‘ocean fertilization’ can mitigate against climate change. The Lohafex project was investigating suggestions that carbon dioxide can be removed from the atmosphere by promoting algal blooms with iron. Despite protests from some groups, researchers aboard the Polarstern research vessel carried out their experiment this month. However, the Alfred-Wegener institute, which was backing Lohafex, says “only a modest amount of carbon sank out of the surface layer by the end of the experiment. Hence, the  … Read more

Ocean acidification disorients fish, riles up scientists

Ocean acidification disorients fish, riles up scientists

I may need to start a file for ‘ocean impacts we hadn’t thought of’. First there was the projection that the seas will get noisier as a result of ocean acidification, which whale conservation groups were running with at a UN conference in December. Now researchers report in PNAS that ocean acidification may make fish larvae lose the sense of smell they use to find a home.  Read more

The ocean’s next 100,000 years

The ocean's next 100,000 years

Carbon dioxide emitted today – and the warming it causes – could stick around for centuries or millennia, reported Mason Inman over on Nature Reports Climate Change not long ago. New research (subscription) published online in Nature Geoscience this week looks at the impacts of CO2 emissions on the global ocean over a timescale even longer and less imaginable.  Read more

Storm over planned ocean fertilization experiment (updated)

Storm over planned ocean fertilization experiment (updated)

Stimulating algal growth by adding iron to nutrient-poor ocean regions is one of several geo-engineering methods that could possibly mitigate greenhouse warming. But given widespread worries about possibly harmful side-effects on marine life, large-scale ocean ‘fertilization’ is currently not considered advisable.  Read more