Antarctica’s ice melt isn’t consistent: Study

New York: Antarctic ice is melting, contributing massive amounts of water to the world’s seas and causing them to rise, but that melt is not as linear and consistent as scientists previously thought, a new study suggests.

The analysis, of 20 years’ worth of satellite data, shows that Antarctica's ice melts at different rates each year, meaning the models scientists use to predict coming sea level rise might also need adjusting. “The ice sheet is not changing with a constant rate – it’s more complicated than a linear change,” said lead author Lei Wang, Assistant Professor at the Ohio State University in the US.

The study is built on data from NASA's GRACE (Gravity Recovery and Climate Experiment), a two-satellite mission that measures changes in the world's oceans, ground water and ice sheets.

Models that predict sea-level rise are typically built around the assumption that ice is melting from the world's largest ice fields in Antarctica and Greenland at a consistent rate.

But this analysis found that, because the mass of ice on the Antarctic Ice Sheet changes depending on the season and year, those projections are not as reliable as they could be.

Extreme snowfall one year, for example, might increase the amount of ice in Antarctica. Changes in the atmosphere or surrounding ocean might decrease it another year.