Water staircases in seas
Scientists have proposed a possible mechanism by which the upper layers of the Arctic Ocean warm up, causing the ice to melt.
What’s it?
According to a research, internal waves, which move vertically through the ocean, sometimes pass through water staircases, which are steplike variations of density of water, in such as manner as to churn up the underlying warm, salty water, thereby increasing the temperature of the top, cooler layers.
What are water staircases?
Water staircases are steplike variations of density of water due to steplike changes in temperature and salinity.
Where do internal waves exist?
Internal waves exist where the density gradually increases with depth. They cannot propagate where the density is uniform.
How Arctic Ocean is being affected by this mechanism?
The Arctic Ocean has inflows coming from the Pacific Ocean and Atlantic Ocean. In this, the top layers consist of cooler and less saline water and below that is a layer of water coming from the Atlantic Ocean which is more saline and warmer, too. The effect of salinity wins over that of temperature and so, though the water below is warmer, it is heavier than the cooler, less saline layer on top.
- Warm, but salty water — ultimately originating from the Atlantic Ocean resides near the bottom of the Arctic Ocean. If turbulence could somehow mix this water with that above, then, eventually, the surface could warm more rapidly, and this would increase the rate of sea-ice melt.
