Wednesday, 29 June 2011
My EPQ is based around ocean circulations, something which I have very limited knowledge on, and so I am going to start at the beginning with the basics.......
The Coriolis Effect:
The rotation of the Earth has impacts on the circulation path taken by the winds and the oceans. If the Earth didn't rotate then the atmosphere would circulate to and from the polar regions (areas of high pressure) and the Equator (an area of low pressure) in a continual motion. However, the Earth does rotate.............
As a consequence of the Coriolis Effect the Ekamn Spiral occurs. Surface water molecules are moved by the winds and as they move, they drag deeper layers of water molecules, located below them, with them. Similarily to the surface water, deeper layers of water are also effected by the Coriolis Effect but, as successive layers of water move slower, a spiral effect is created (the Ekman Spiral) as the different layers of water move slower to the right or left. The movement of water, due to the combination of the wind direction and surface water movement, is known as Ekman Transport. Ekman Transport produces variations in the height of the sea surface (as it removes water from some areas and builds it up in others) and so causes the surface to slope gradually. This slight sloping of the surface develops horizontal differences in water pressure and this pressure gradient leads to geostrophic flow.