Circulation Patterns

Question 1

What direction does the earth rotate?

Answer 1

From West to East

Question 2

What force is produced when air is travelling West to East?

Answer 2

Centrifugal Force

Question 3

What is centrifugal force?

Answer 3

When air is rotating around the earth in the same direction as it rotates itself, this causes it to be forced/diverted away from the earth’s centre point of rotation

Question 4

What is the counteracting force to centrifugal force?

Answer 4

Gravity

Question 5

What is the net result of centrifugal force and gravity upon a body of air travelling west to east at a latitude >5?

Answer 5

The balance between the two forces causes the body of air to be pulled towards the equator.

Question 6

What causes travelling bodies of air from West to East to veer to the right in the northern hemisphere and left in the southern hemisphere?

Answer 6

Coriolis Force: The imbalance between gravity and centrifugal force means one is stronger than the other and so causes the body of air to veer away from its primary direction of travel.

Question 7

Why is there variation in the strength of the Coriolis force/veering with latitude upon bodies of air travelling West to East?

Answer 7

The strengths of the centrifugal force and gravity between the poles and equator changes along a spectrum correlated with latitude. This means that one is maximum at one latitude and the other dominates at another, then it is appropriated along that latitudinal spectrum

Question 8

What is the balance between gravity and centrifugal force at the poles? What does this mean for Coriolis force?

Answer 8

At the poles gravity is maximum and centrifugal force is 0. This means that here Coriolis force and veering of winds is strongest.

Question 9

What is the balance between gravity and centrifugal force at the equator? What does this mean for Coriolis force?

Answer 9

At the equator centrifugal force is maximum and gravity is at its minimum. This means that here Coriolis force and veering is weakest.

Question 10

What is the correlation with latitude and Coriolis force?

Answer 10

As latitude increases, Coriolis force increases

Question 11

What is the net result of centrifugal force and gravity upon a body of air travelling from West to East at latitudes <5?

Answer 11

Centrifugal force is at its maximum whereas gravity is at its minimum which means there is not much force available to cause veering and it is already at the equator

Question 12

If air is travelling East to West is it travelling in the same or opposite direction to the rotation of the earth?

Answer 12

Opposite

Question 13

What force is inflicted upon a body of air travelling from East to West?

Answer 13

Reverse centrifugal force

Question 14

What is reverse centrifugal force?

Answer 14

Air travelling in the opposite direction to that of the earth’s rotation will encounter friction with the rest of the atmosphere that is rotating with it. This will cause it to slow down and thus loose momentum forcing it towards the point of rotation and down to the earth’s surface

Question 15

What is the opposing force to reverse centrifugal force? What impact does this have?

Answer 15

Not a force as such but the earth’s surface obstructs the air descending to the point of rotation from reaching it and forcing it out to the atmosphere?

Question 16

What is the net result of reverse centrifugal force and the earth’s surface upon a body of air travelling East to West at latitudes >5?

Answer 16

Air is pulled towards the poles

Question 17

What causes bodies of air travelling East to West to veer to the right in the northern hemisphere and to the left in the southern hemisphere?

Answer 17

Coriolis Force: Imbalances between the reversed centrifugal force and bouncing off the earth’s surface causes unstableness and subsequent veering

Question 18

Why is there variation in the strength of the Coriolis force upon bodies of air travelling East to West?

Answer 18

The strengths of the reverse centrifugal force and earth surface bouncing between the poles and equator changes along a spectrum correlated with latitude. This means that one is maximum at one latitude and the other dominates at another, the relationship is then appropriated along that latitudinal spectrum

Question 19

What is the balance between reverse centrifugal force and earth surface bouncing at the poles? What does this mean for Coriolis force?

Answer 19

At the poles reverse centrifugal force is weakest and bouncing is constant this causes there to be a stronger centrifugal force and subsequently more veering

Question 20

What is the effect of reverse centrifugal force at the equator? What does this mean for Coriolis force?

Answer 20

At the equator reverse centrifugal force is maximum, bouncing is constant, this causes there to be very week if any Coriolis force

Question 21

What is the correlation with Coriolis force and latitude?

Answer 21

Force strength increases with latitude

Question 22

What is the net result of reverse centrifugal force and earth surface bouncing upon a body of air travelling East to West at latitudes <5?

Answer 22

The reverse centrifugal force is not impacted much and so it means there is a weak Coriolis force and little amount if no veering?

Question 23

What is the combined effect of winds travelling in both directions around the earth?

Answer 23

If winds travelling to poles and equator in the northern hemisphere are veered right this causes descending (most) air to rotate in clockwise patterns. In the southern hemisphere winds are veered left and so form an anticlockwise patterns.

Question 24

What latitude bands feature the highest atmospheric pressure?

Answer 24

Sub-tropics and to a lesser extent the poles due to the ice

Question 25

What type of surfaces is atmospheric pressure highest and why?

Answer 25

Oceans and Ice - this is because relative to the land they are much cooler which means air above them is much denser and so descends much more.

Question 26

What is geostrophic force?

Answer 26

The balance between a pressure gradient and gravity. Air travel down the pressure gradient from high to low pressure and gravity assists with the movement

Question 27

What is the most efficient route for a body of air to take down the pressure gradient?

Answer 27

Direct route from the peak of high pressure to low pressure. This is likely to be perpendicular to the gradient.

Question 28

What causes inefficiency in the route that a body of air takes down a pressure gradient? How?

Answer 28

Coriolis Force - it causes the air to divert off path and so the route becomes longer and less efficient

Question 29

What is the net result of the Coriolis force and geostrophic force?

Answer 29

Coriolis force is attempting to divert the air 90 degrees of its direction being determined by the geostrophic force. This means that at each pressure band the wind is veered ~45 degrees of its intended direction. This produced a spiral

Question 30

What type of spiral forms in a high pressure system? Why?

Answer 30

The air is travelling from an area of high to low pressure so this means the spiral is clockwise and downward. This process is reversed in the southern hemisphere

Question 31

What type of spiral forms in a low pressure system? Why?

Answer 31

The air is travelling from low to high pressure so this means the spiral is anticlockwise and upward. This process is reversed in the southern hemisphere

Question 32

What is an ocean gyre?

Answer 32

the ocean circulation mechanisms

Question 33

What is the direction of ocean gyres initially determined by? Why? (Keyword)

Answer 33

The atmospheric pressure located above them. If air is travelling in an anticlockwise/clockwise direction then oceans will follow due to the frictional drag exerted above.

Question 34

What is the secondary influence on ocean gyre direction? Why?

Answer 34

Even though the atmospheric patterns are determined by the Coriolis force, the oceans are separately affected by the same force. This means they rotate even more in theory and so actually flow inward to the centre of the oceans.

Question 35

What accumulates in the middle of the oceans as a result of the inward flow?

Answer 35

Salt

Question 36

What does the accumulation of salt in the middle of the ocean alter? What rate does this effect?

Answer 36

Density - the middle parts are much more denser than the edges. This means they are much harder to evaporate.

Question 37

If the salt located in the middle of the ocean is unable to be evaporated then where does it flow and why?

Answer 37

Down a pressure gradient from areas of high salinity to low salinity - think to geostrophy

Question 38

Where are the largest ocean gyres and therefore the largest concentrations of saline water?

Answer 38

Atlantic Ocean

Question 39

How does normal upwelling work within oceans?

Answer 39

Ocean gyres on the West coast of continents draw the warmer surface waters away towards the east coast on the other side of the ocean. This allows deeper cold water to upwell on the western coasts

Question 40

How does equatorial upwelling work within oceans?

Answer 40

Surface winds being diverted away from the equator drag the ocean surface with them which allows the deeper parts to upwell.