Research Suggests Deep Ocean Currents Near Antarctica Could Collapse Soon
Scientists firmly believe that the deep ocean circulation that tends to form around Antarctica is about to collapse. Such a decline in ocean circulation is expected to stagnate the bottom of the oceans and generate further impacts affecting the marine and climatic ecosystems for many centuries.
The results have been detailed in a study coordinated by Matthew England, Scientia Professor and Deputy Director associated with the ARC Centre for Excellence in Antarctic Science at UNSW Sydney.
The work, published in Nature, includes the lead author Dr Qian Li — formerly associated with UNSW and now working with the Massachusetts Institute of Technology (MIT) — and co-authors from the Australian National University and CSIRO.
The model also captures the detail of the ocean procedures that earlier models could not, including how the predictions for meltwater from the ice could influence circulation.
This deep ocean current has been in a relatively stable condition for thousands of years now. Still, with rising greenhouse gas emissions, this Antarctic overturning is estimated to significantly slow down over the coming decades.
Effects of lowered Antarctic overturning
With the collapse of the deep ocean current, the oceans that lie below 4000 meters will stagnate. This will trap the nutrients in the deep sea, bringing down the nutrients available for supporting marine life near the ocean surface, explains says Prof England,
Co-author of the study, Dr Steve Rintoul of CSIRO, and suggestions from the Australian Antarctic Program Partnership indicate that model simulations reflect a slowing of overturning, which leads to excessive rapid ocean warming.
Modelling the deep ocean
Almost 250 trillion tons of cold, oxygen-rich, and salty water sinks near Antarctica each year. This water spreads northward and carries oxygen into the Pacific, Atlantic, and Indian Oceans.
If oceans had their lungs, this would be one of those, Prof England comments.
The international team that comprises experienced scientists modelled the amount of Antarctic deep water generated per the IPCC “high-emissions scenario” till 2050.
Reference: The News Mill, DNA India