GENEVA: Researchers have developed a novel and more accurate method to measure ocean temperatures by using the concentration of noble gases in Antarctic ice, which helps to conclude on the changes in sea temperature from the last ice age to the present day, according to a press release by the Swiss Federal Laboratories for Materials Science and Technology (EMPA).

An international team of researchers, including those from EMPA and the University of Bern, has come up with the method that uses ice cores from Antarctica to more accurately measure average global ocean temperatures over the past 24,000 years, during which the transition from the last ice age occurred.

The layers of permanent ice in that region form an "archive of the atmosphere" that contains trapped bubbles of air and other gases known as noble gases, including krypton, xenon and argon.

As cooling water absorbs noble gases from the atmosphere and warming water releases them, the concentration of noble gases in these ice core bubbles can help scientists estimate the average temperature of the ocean at the time.

Using this method, the researchers identified an increase of 2.6 degrees Celsius in average ocean temperature over a period of 10,000 years, which has been published in the scientific journal Nature.

The team also believe that the method could in theory be useful for monitoring current temperature changes, and not just large-scale changes like the shift from the last ice age to the current warm age.

That is important because as the global climate warms, most of the extra heat is absorbed by the oceans. Until now, measurements of average ocean temperature have been very complicated to produce and are often distorted by variations in location, season, and ocean depth.

According to EMPA, the basic idea of using the connection between the concentration of noble gases in the atmosphere and the average ocean temperature is correct and that the method works. Xinhua