<
https://theconversation.com/torrents-of-antarctic-meltwater-are-slowing-the-currents-that-drive-our-vital-ocean-overturning-and-threaten-its-collapse-202108>
"Off the coast of Antarctica, trillions of tonnes of cold salty water sink to
great depths. As the water sinks, it drives the deepest flows of the
“overturning” circulation – a network of strong currents spanning the world’s
oceans. The overturning circulation carries heat, carbon, oxygen and nutrients
around the globe, and fundamentally influences climate, sea level and the
productivity of marine ecosystems.
But there are worrying signs these currents are slowing down. They may even
collapse. If this happens, it would deprive the deep ocean of oxygen, limit the
return of nutrients back to the sea surface, and potentially cause further melt
back of ice as water near the ice shelves warms in response. There would be
major global ramifications for ocean ecosystems, climate, and sea-level rise.
Our new research, published today in the journal
Nature, uses new ocean model
projections to look at changes in the deep ocean out to the year 2050. Our
projections show a slowing of the Antarctic overturning circulation and deep
ocean warming over the next few decades. Physical measurements confirm these
changes are already well underway.
Climate change is to blame. As Antarctica melts, more freshwater flows into the
oceans. This disrupts the sinking of cold, salty, oxygen-rich water to the
bottom of the ocean. From there this water normally spreads northwards to
ventilate the far reaches of the deep Indian, Pacific and Atlantic Oceans. But
that could all come to an end soon. In our lifetimes."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
