Researchers have revealed a new process in the Antarctic that is causing the melting of glaciers as well as increasing sea levels and aiding climate change.
The new process was discovered by a team of scientists led by IMAS PhD student Alessandro Silvano and published in the journal Science Advances. In the study scientists have revealed a previously undocumented process where melting glacial ice sheets change the ocean in a way that further accelerates the rate of ice melt and sea level rise.
Researchers found that glacial meltwater makes the ocean’s surface layer less salty and more buoyant, preventing deep mixing in winter and allowing warm water at depth to retain its heat and further melt glaciers from below.
The study found that fresh meltwater also reduces the formation and sinking of dense water in some regions around Antarctica, slowing ocean circulation which takes up and stores heat and carbon dioxide. Scientists say that the cold glacial meltwaters flowing from the Antarctic cause a slowing of the currents which enable the ocean to draw down carbon dioxide and heat from the atmosphere.
These two processes are feeding off each other to further accelerate climate change. The scientists add that a similar mechanism has been proposed to explain rapid sea level rise of up to five metres per century at the end of the last glacial period around 15 000 years ago.
The feedback process is not only possible but is in fact already underway, and may drive further acceleration of the rate of sea level rise in the future.