— A guide to the big stories in science
Noble gases can measure the average temperature of the world’s oceans.
It would look nice in a drink, but the air bubbles in this 24,000 year-old ice core drilled from the Antarctic polar ice cap offer a new way to measure the average temperature of the oceans.
Measuring the average temperatures of the oceans is a diabolically difficult thing to do. While 90% of the planet’s heat is sunk into the oceans, it is unevenly distributed.
Bernhard Bereiter, of the Scripps Institution of Oceanography, and his colleagues measured the concentrations of noble gases within the air bubbles trapped within the ancient ice.
They believed noble gases like argon could provide a precise thermometer. Cool oceans absorb noble gases while warming oceans release them into the atmosphere. Because the noble gases don’t interact with other molecules, they just shuffle between the atmosphere, the ocean and back.
“Our study clearly shows that the basic idea – the connection between the concentration of noble gases in the atmosphere and the average ocean temperature – is correct,” says Bereiter.
The study, “Mean global ocean temperatures during the last glacial transition”, was published in Nature.