Researchers are inferring that the Antarctica’s diminishing glaciers are melting from the bottom up, but a number of robotic sea gliders might help explain why.
The researcher published a study in Nature Geoscience journal on 10th November reporting, “Underneath the icy Weddell Ocean in West Antarctica, the gliders found turbulent warm power near ice shelves, the large floating platforms where continental glaciers pull out icy tongues into the ocean. The whirling eddies bring pulses of tepid water to the trivial depths beneath the ice.”
The lead author of the study and a physical oceanographer at Caltech, Andrew Thompson said, “What we are searching at is delivery of heat up to the ice shelf, in which the sea touches up against the ice. It’s similar to a splotch of tepid water, just a little ocean storm.”
Earlier studies already pointed to tepid to warm water – instead of warmer air temps – as the basis behind Antarctica’s retreating ice shelves. (The vanishing ice belongs to the continental ice sheet, not the ocean ice that freezes and melts every year.) However, to verify these accusations, the scientists required to get underneath the ice to determine how the procedure works.
Way back in 2012, Thompson along with his team from the College of East Anglia, in the UK, used remote controlled gliders to investigate the ocean conditions near ice shelves inside the Weddell Sea. The gliders rise and sink without propellers, depending rather on a battery-driven pump that alters their resilience through a fluid-filled bladder. Every few several hours, the 1.8 meters glider surfaces and uploads its data through a satellite phone network. The gliders monitored temperature and salinity data for just two months, studying the upper 0.6 miles of the ocean.
Thompson told LiveScience, “Once the gliders hit an eddy, the lustrous yellow robots were frequently swept up within the effective vortices. You can almost know from where it emerged that it had hit this jarring region. The glider would go down and ended up in a quite different place.”
However, the researcher explained in the study that how warm water rises from deeper levels to reach the floating ice shelves. The study findings propose the stormlike currents bring up pulses of warm water, which flow underneath the ice at irregular periods. Now, scientists have to discover what goes on if this heat reaches the grounding line, the place where glaciers transfer how much they weigh from the continent to the ocean. This is when the majority of the melting happens, Thompson added.
Thompson stated that, “What we are observing from the gliders is that it’s not a stable circulation in and out. This is actually the initial step of understanding of what heat goes in, and how efficient that heat is in melting the ice shelves.”
Moreover, the other layers of cold and warm water surrounding Antarctica, it just takes only a couple of degrees difference to dissolve a glacier. Usually, the warm water is in the center layer of the ocean. Coming from the North, it shipped on a huge current known as ‘Global Conveyor Belt’. In contrast, cold water lies on the surface, frequently created as cold wind blows up over the ocean and sea ice freezes up. Dense, cold water is also on the ocean bottom.