Does thermohaline circulation cause upwelling?
Upwelling. All these dense water masses sinking into the ocean basins displace the older deep-water masses that were made less dense by ocean mixing. However, because this thermohaline upwelling is so widespread and diffuse, its speeds are very slow even compared to the movement of the bottom water masses.
How does upwelling relate to thermohaline circulation?
The upwelling branch of the thermohaline circulation is important for the ocean’s biota as it brings nutrient-rich deep water up to the surface. The thermohaline circulation is thought to be vulnerable to the warming and freshening of the Earth’s polar regions associated with global warming.
Why are thermohaline currents downwelling & upwelling important to marine life?
Currents also are a major factor in ocean ecosystems. Two types of current motion, upwelling and downwelling, strongly influence the distribution and abundance of marine life. The importance of upwelling to surface organisms is matched by the need of sea bottom life for downwelling, or the sinking of surface water.
Why is downwelling important?
Why is downwelling important? It brings down oxygen that animals in deeper water need. Why is upwelling important? It brings up nutrients that algae and other animals need that live close to the surface.
How does downwelling alter the oceanographic properties of deep ocean waters?
Downwelling. Changes in temperature and salinity of seawater take place at the surface. Fresh water freezes out of seawater to become sea ice, which also increases the salinity of the remaining water. This very cold, very saline water is very dense and sinks.
How does downwelling affect productivity?
Downwelling is where surface water is forced downwards, where it may deliver oxygen to deeper water. Downwelling leads to reduced productivity, as it extends the depth of the nutrient-limited layer. As the surface waters diverge, deeper water must be brought to the surface to replace it, creating upwelling zones.
How does downwelling affect ocean life?
In the most extreme cases, a lack of downwelling may lead to mass extinctions. Low oxygen, sulfide and methane-rich waters filled the ocean deeps and then spread onto the continental shelves, wiping out 95% of all marine species in the greatest extinction event in Earth history.
What happens during downwelling?
Downwelling occurs when the water on the surface of the sea becomes denser than the water beneath it and so it sinks. Seawater gets denser when it gets colder or saltier.
Does divergence create upwelling or downwelling?
movement of ocean currents …downward in a process called downwelling, while a region of divergence draws water from below into the surface Ekman layer in a process known as upwelling. Upwelling and downwelling also occur where the wind blows parallel to a coastline.