Question:
Explain why the Mediterranean Outflow Water flows northward to flow along the continental slope and not directly into the North Atlantic Ocean.
To aid your writing, add at least one diagram.
Answer:
Introduction
After the Mediterranean water had gone through the Espartel Dill, which could be 360m deepness and the westernmost sill of the Straits of the Straits of the, the Mediterranean Outflow Water flow was formed (Gibraltar Bower Serra, and Ambar 2002).
The Mediterranean outflow water flows through the Gulf of the Cadiz’s smaller surface levels. This could be due to the pressure gradients created by the excess density of the Mediterranean water flow. It is in direct proportion to the ambient North Atlantic Central Water (Gibraltar Bower Serra and Ambar 2002).
The Mediterranean water flow flows to the middle slope via the bottom bathymetry, which is the natural extension of the Strait of Gibraltar. This channel then creates into the Gulf of the Cadiz.
Because of the dense water that forms on the top of the ocean water by cooling, evaporation and creation above the continental shelf, the Mediterranean outflow water flows northwards rather than flowing directly into the North Atlantic Ocean.
The horizontal density gradient results in a trade-off between dense water and open ocean (Gasser Pelegri Nash Peters, Garcia-Lafuente and Garcia-Lafuente (2011)
The dense water can reach the deep ocean basin at irregular depths by overflowing the shelf edge, or perhaps performing a function such as the strait or sill.
The water can then descend down the steep continental slope to reach the open ocean.
This creates a density-driven bottom of gravity current, which can be referred to as the overflow, or possibly the cascade, which then flow under the balance gravity, rotation of earth and frictional forces (Jungclaus & Mellor 2000).
As a result, the overflow causes the oceanic water to descend and entrain a substantial amount of salty water. This alters the temperature and increases the volume.
The intensity of the combining-and-effect varies greatly between outflows and the product water. They then disperse into ocean interior (Jungclaus & Mellor 2000).
These may differ from the initial source water that enters the deep ocean basin.
Figure 1: The deep water formation at the Mediterranean water outflow
Dense overflows will descend to a depth at which the density is equal to that of the surrounding ocean water.
The initial water mass properties, entrainment, and properties of the surrounding water, are all factors that determine the depth (Gasser-Pelegri, Nash Peters, Garcia-Lafuente and Garcia–Lafuente (2011)).
Descended water leaves the incline and can spread isopycnally to the interior of ocean, either reaching the bottom or becoming the bottom mass.
Entrainment is what causes the saltiness and density of the Mediterranean outflow to drop very significantly.
The mixture of Mediterranean water can then reach the Cape Vincent.
Refer to
Bower, A.S.S., Serra N., and Ambar I., 2002.
Structure of the Mediterranean Undercurrent, and Mediterranean Water spreading around southwestern Iberian Peninsula.
Journal of Geophysical Research: Oceans. 107 (C10).
Gasser M., Pelegri J.L., Nash J.D., Peters H. and Garcia Lafuente J.
Topographic control of the Mediterranean outflow.
Jungclaus, J.H.
Three-dimensional modeling of the Mediterranean outflow.
Journal of Marine Systems, 24(1) pp. 41-66.