February 8th lecture

Question 1

Ekman transport can lead to weer being piled up or being removed from an area. What is this called?

Answer 1

When water piles up it is called Convergence

When water is removed it is called divergence

Question 2

If the winds blew continuously would we see a continual pile up or removal of water? why?

Answer 2

no we would not see a continual pile up or removal of water?

Other motions tend to try and restore the sea surface towards a “flat”state.

Question 3

What are the motions that try and restore the ocean back to a flat state?

Answer 3

They are Horizontal pressure gradients

Question 4

How do pressure gradients work in the ocean?

Answer 4

Pressure gradient forces move water from high
pressure regions under an elevated sea surface to
low pressure regions

Question 5

What is the difference between Ekman transport and pressure gradient transfer?

Answer 5

Unlike Ekman motion, pressure gradients transfer occurs at all depths where a pressure gradient may be found

Question 6

Can Ekman transport and Pressure gradient transport flow in opposite directions?

Answer 6

Pressure flow in deeper layers may oppose the Ekman transport

Question 7

What is a result of Pressure gradient movement in the ocean

Answer 7

It produces upwelling and downwelling

Question 8

What must we consider if pressure gradient forces generate motion?

Answer 8

The Coriolis effect

Question 9

How does the Coriolis effect alter the flow of Pressure gradients?

Answer 9

As the water parcel starts to move, it is deflected by the coriolis effect so that the direction of flow is no longer directly down the pressure gradient.

Question 10

How are pressure gradients balanced by the Coriolis effect? What happens to the resulting current?

Answer 10

Flows are accelerated and deflected until the pressure gradient is balanced,

The resulting Geistrophic current is thus deflected 90 degrees to the right of the pressure gradient in the northern hemisphere

Question 11

What is a Geostrophic current?

Answer 11

A current that is produced by the balance between the pressure gradient force and the Coriolis force with the direction of the flow 90 degrees to the right of the pressure gradient in the northern hemisphere.

Question 12

What direction is the pressure gradient deflected in the southern Hemisphere die to the Coriolis effect?

Answer 12

The flow is 90° to the left of the pressure gradient in the southern
hemisphere

Question 13

In real world applications do we ever see actual geostrophic currents?

Answer 13

No, other affects come into play such as friction.

Question 14

What are ocean currents inintaed by?

Answer 14

Ekman transport

Question 15

What are surface currents maintained as>?

Answer 15

Geostrophic currents

Question 16

how deep do open ocean surface currents go?

Answer 16

they generally reach a few hundred meters deep although some can reach as far as 2km

Question 17

What is a Sverdrup?

Answer 17

one typical ocean unity of volume transport

Question 18

What is ekman transport based on? what does it lead to?

Answer 18

it is based on large scale atmospheric circulation.

Leads to bands of convergence and divergence

Question 19

What do Ekman transport chains lead to?

Answer 19

large scale geostrophic currents that would flow around the earth.

Question 20

What can alter the circulation of gyers?

Answer 20

The presence of land

Question 21

Where in the world can currents flow all around the world?

Answer 21

in the south of the southern hemi-sphere

Question 22

At most latitudes waht type of currents do we get due to the presence of land deflecting currents?

Answer 22

Zonal currents

Question 23

What are gyers>

Answer 23

Closed circulation loops within the ocean

Question 24

What are subtropical gyers?

Answer 24

gyes which flow clockwise or anti-cyclonic in the northern hemi-sphere

Question 25

What are sub-polar gyers?

Answer 25

Gyers that flow counter clockwise or cyclonic in the northern hemisphere