The ice thickness map shows a forecast of the thickness of the sea ice, run on May 20, 2021 and valid for May 21, 2021.

An area is visible north of Severnaya Zemlya toward the North Pole where thickness is getting very thin, while there is one spot where the ice has virtually disappeared.

The spot is likely a melting iceberg, the animation at the post shows that the spot has been there for quite a few days, while the freshwater in this spot appears to result from the melting amidst the salty water.

Overall, sea ice is getting very thin, indicating that the buffer constituted by the sea ice underneath the surface is almost gone, meaning that further heat entering the Arctic Ocean will strongly heat up the water.

The salinity animation shows freshwater entering the Arctic Ocean due to runoff from land, i.e. rainwater from rivers, meltwater from glaciers and groundwater runoff from thawing permafrost.

At the same time, very salty water is entering the Arctic Ocean from the Atlantic Ocean.

Sea ice acts as a buffer, by consuming energy in the process of melting, thus avoiding that this energy causes a temperature rise of the water.

As long as there is sea ice in the water, this sea ice will keep absorbing heat as it melts, so the temperature will not rise at the sea surface and remain at zero°C. The amount of energy that is consumed in the process of melting the ice is as much as it takes to heat an equivalent mass of water from zero°C to 80°C.

The accumulated ice melt energy until now is the highest on record, as illustrated by the image by Nico Sun.

As the temperature of the water keeps rising, more heat will reach sediments at the seafloor of the Arctic Ocean that contain vast amounts of methane.

Ominously, methane levels reached a peak of 2901 ppb at 469 mb on May 13, 2021.

From the post 'Arctic Ocean invaded by hot, salty water', at:
https://arctic-news.blogspot.com/…/arctic-ocean-invaded-by-…