Upload
genepearl-divinagracia
View
219
Download
0
Embed Size (px)
Citation preview
8/12/2019 Ocean Current .
1/14
By: Gene Pearl R. Divinagracia
8/12/2019 Ocean Current .
2/14
What is Current?
A current is a large stream of water that flows through the
ocean Or mass of water moving from one place to another
importance:
moves drifting organisms from place to placeplankton,
disperse young
carries eggs and larvae of organisms that have external
fertilization
brings food, oxygen carries away waste,
pollutants
8/12/2019 Ocean Current .
3/14
Two types of currents
Surface Currents
Deep Currents
8/12/2019 Ocean Current .
4/14
Surface Currents Driven mainly by the wind
They follow Earths major wind patterns which move in a
circular pattern
8/12/2019 Ocean Current .
5/14
Surface Currents
About 10% of the water in the world ocean is involved in
surface currents, which are water flowing horizontally in
the uppermost 400 meters (1,300 feet) of the oceansurface
Due to the Coriolis effect, currents in the Northern
Hemisphere curve to the right and to the left in the
Southern Hemisphere.
8/12/2019 Ocean Current .
6/14
Surface CurrentsIn physics, the Coriolis effect is a deflection of moving
objects when they are viewed in a rotating reference
frame. In a reference frame with clockwise rotation, thedeflection is to the left of the motion of the object; in one
with counter-clockwise rotation, the deflection is to the
right.
8/12/2019 Ocean Current .
7/14
The Coriolis effect
Is a result of Earths rotation
curves or deflects the path of global winds
Example: rolling a ball over a spinning disk will curve the line of
travel
-> N. Hemisphere- turn clockwise and in the S. Hemisphere- turn --
counterclockwise
Coriolis Effect Caused by the rotation of Earth
8/12/2019 Ocean Current .
8/14
Deep Currents Deep currents occur within our oceans and are not controlled by global winds but by
density or density cause them to move.
Higher temperatures and Lower salinity= decreased density
Lower temperatures and higher salinity= increased density
8/12/2019 Ocean Current .
9/14
Deep currents flow slowly. They may take as long as
1,000 years to flow from pole to equator and back
again.
Make up about 90% of oceans water
Deep Currents
8/12/2019 Ocean Current .
10/14
8/12/2019 Ocean Current .
11/14
Density Impact on Water Movement
A. Decreasing Temperature
Cold, arctic air decrease heat energy and
therefore temperatures at the surfacedecrease. Water becomes more dense and
sinks and travels towards the equator.
8/12/2019 Ocean Current .
12/14
Increasing Salinity via Freezing
Ice floats as it is less dense than the liquidwater and the dissolved solids are not frozen
and add salinity to the liquid water beneath
the ice. Higher salinity = higher density and
the water sinks.
8/12/2019 Ocean Current .
13/14
Increasing salinity via evaporation
In warm climates, water molecules at the
surface evaporate leaving behind dissolved
solids which increases salinity. Denser water
sinks.
8/12/2019 Ocean Current .
14/14