Which mechanism primarily drives deep ocean thermohaline circulation downwelling in polar regions?

💡 Explanation

When seawater freezes to form sea ice, salt is excluded, increasing the density of the remaining water because the higher salinity and lower temperature result in denser water sinking. Therefore density increase drives downwelling, rather than wind, tides, or glacial melt, which induce different flow patterns.

• Which effect does the Coriolis force primarily have on large-scale ocean currents, leading to gyre formation?
• Which process establishes distinct stratification layers within a dimictic lake?
• Which hydrogeologic mechanism causes the formation of a kettle lake following glacial retreat where till depression exists?
• Which outcome results downstream when glaciers accelerate surge flow?
• Which geologic process primarily scours and deepens a fjord's U-shaped valley profile?
• Which risk increases following rapid glacial isostatic rebound?