Exploration of the ocean near Antarctica during the winter has helped scientists understand the mechanism of how the continent's ice sheet melts.
Much of the research into the ocean near ice so far has been done in the summer, ignoring the winter months when the sea freezes over. But scientists from the Institute of Marine and Antarctic Research (Australia) have developed a methodology that makes it possible to measure the ocean near glaciers all year round. The researchers wrote about this in an article published in the Journal of Geophysical Research.
To obtain the necessary data, the scientists used instruments known as Argo buoys as a basis. These devices drift in the ocean and measure its temperature and salinity. For the Antarctic exploration, experts had to slightly alter the buoys so that they stay in one place in the water column. This innovation made it possible to measure even when the water surface is covered with ice.
Researchers tested the new method near the rapidly melting Totten Glacier in eastern Antarctica. Measurements have shown that in the winter months, the ocean temperature near the glacier is higher than in summer or spring. This means that the glacier melts faster in winter, therefore, summer measurements cannot be considered a reliable indicator of the rate of ice melting.
One of the buoys of the Argo / Argo project.
Researchers have found an explanation for this phenomenon: it turns out that part of East Antarctica, where the Totten Glacier is located, is more susceptible to the effects of warm ocean currents. The new data, scientists say, is changing ideas about the rate of glacier melting and sea level rise.
Scientists have previously expressed their concern about the melting of the Totten glacier. Due to the fact that warm water washes over its base, the upper part also begins to melt. According to experts, if Totten disappears, it could raise the level of the World Ocean by two meters.