1. Currents and Climate

2. There are two types of currents: There are two types of currents: –Surface –Density

3. Surface Currents Affect only water to a depth of 100m Affect only water to a depth of 100m Are cold or warm depending on their starting location. Are cold or warm depending on their starting location. Caused by the wind Caused by the wind –Due to the spinning of the Earth the currents in the Northern Hemisphere curve to the right (clockwise), and in the Southern Hemisphere curve to the left (counter clockwise). This factor is called the Coriolis Effect.

4. Surface Currents

5. Currents and Climate As the currents in the oceans move past the continents, they affect the climate on land. As the currents in the oceans move past the continents, they affect the climate on land. The Gulf Stream brings warm water to areas in the North Atlantic that should not be that warm. (British Isles, Iceland) The Gulf Stream brings warm water to areas in the North Atlantic that should not be that warm. (British Isles, Iceland) Cold Currents in the Pacific make the ocean off the Wash./Oregon coast extremely cold, even in the summer. Cold Currents in the Pacific make the ocean off the Wash./Oregon coast extremely cold, even in the summer.

6. Density Currents These are deep currents that cause water to creep along the bottom of the ocean floor. These are deep currents that cause water to creep along the bottom of the ocean floor. The cold waters near the poles, sinks to the bottom; while the warm tropical waters near the equator bring the water to the surface The cold waters near the poles, sinks to the bottom; while the warm tropical waters near the equator bring the water to the surface These currents move and mix the water around the planet. It may take 1000 years for the water at the poles to move to the equator. These currents move and mix the water around the planet. It may take 1000 years for the water at the poles to move to the equator.

7. Density Currents (Deep water Current)

8. Deep water current (side view)

9. Upwellings Sometimes very fast moving winds or a storm will push away the top layers of the water. (Very small isolated areas.) Sometimes very fast moving winds or a storm will push away the top layers of the water. (Very small isolated areas.) This allows the cold, nutrient rich water near the bottom to reach the surface. This allows the cold, nutrient rich water near the bottom to reach the surface. The fish flock to that area because of the high nutrient content, and it makes for great fishing !!! The fish flock to that area because of the high nutrient content, and it makes for great fishing !!!

10. Tides Tides are caused by the interaction of the sun, moon, and the Earth. Tides are caused by the interaction of the sun, moon, and the Earth. Gravity is pulling the Earth towards the moon and towards the Sun. It’s what keeps us in our orbit! Gravity is pulling the Earth towards the moon and towards the Sun. It’s what keeps us in our orbit! That pull of gravity, causes the water on the Earth to be pulled further in one direction at different times of the month. That pull of gravity, causes the water on the Earth to be pulled further in one direction at different times of the month.

11. Daily Tides Every day there are high tides and low tides. At the Jersey Shore, there are 2 high tides and 2 low tides every day. Every day there are high tides and low tides. At the Jersey Shore, there are 2 high tides and 2 low tides every day. Why would it be important to know the times of these tides? Why would it be important to know the times of these tides?

12. Semidiurnal tides As the earth turns upon its own axis in about 24 hours, a point on the earth moves through areas with these different forces acting on it. In one rotation (one day), a point on earth travels from an area of high tide (where there is a force pulling water outward), through an area of low tide, through and area of high tide again (the opposite pull), and through another area of low tide, before it returns to the point of origin at high tide. This results in two high tides and two low tides in a day (called semidiurnal tides). As the earth turns upon its own axis in about 24 hours, a point on the earth moves through areas with these different forces acting on it. In one rotation (one day), a point on earth travels from an area of high tide (where there is a force pulling water outward), through an area of low tide, through and area of high tide again (the opposite pull), and through another area of low tide, before it returns to the point of origin at high tide. This results in two high tides and two low tides in a day (called semidiurnal tides).

13. Monthly tides The changes of the alignment of the Earth, Sun and the Moon will cause the tides to be greater than normal or lower than normal. The changes of the alignment of the Earth, Sun and the Moon will cause the tides to be greater than normal or lower than normal. There are two types of monthly Tides: Spring Tides and Neap Tides There are two types of monthly Tides: Spring Tides and Neap Tides

14. Tides Spring Tide Neap Tide

16. Tidal Range The tidal range is the measured distance between the high tide and the low tide. The tidal range is the measured distance between the high tide and the low tide.

17. Spring Tides The Sun, the Moon, and the Earth are all in a straight line. The Sun, the Moon, and the Earth are all in a straight line. Results in the highest high tides, and the lowest low tides (twice a month) Results in the highest high tides, and the lowest low tides (twice a month) Greatest tidal range during the month Greatest tidal range during the month

18. Neap Tides The Sun, the Moon, and the Earth are at right angles to each other The Sun, the Moon, and the Earth are at right angles to each other That makes the lowest high tides and the highest low tides That makes the lowest high tides and the highest low tides The Tidal Range is the smallest The Tidal Range is the smallest