Topic 1- Global Atmospheric Pressure

Question 1

Where is the insolation greater? At the equator or at the poles?

Answer 1

At the equator.

Question 2

How is heat transferred away from the equator?

Answer 2

Winds blow from areas of high pressure to areas of low pressure.

Question 3

What are the names of three circulation cells in each hemisphere?

Answer 3

Hadley, Ferrel, Polar.

Question 4

Fill in the gap:

Warm air rising creates a ………. pressure belt.

Answer 4

Low

Question 5

Fill in the gap:

Cool falling air creates a ……….. pressure belt.

Answer 5

High

Question 6

What happens at the equator?

Answer 6

Warm air rises—> cools and condenses—> forms clouds and rain.

Question 7

Where is the air transferred after the equator?

Answer 7

The cool, dry air moves out to 30º north and south of the equator.

Question 8

What happens at 30º north and south of the equator?

Answer 8

Cool air sinks—> high pressure belt created—> cloudless skies and very low rainfall.

Question 9

What happens after the cool air sinks at 30º north and south of the equator?

Answer 9

Cool air reaches the ground surface and moves as surface winds either back to the equator (trade winds) or towards the poles (westerlies).

Question 10

What happens at 60º north and south of the equator?

Answer 10

The warm surface winds meet the cool air from the poles. The warmer air is less dense than the cold air so it is forced to rise, creating low pressure and frontal rain.

Question 11

What happens at the poles?

Answer 11

Cool air sinks, creating high pressure. The high pressure air is drawn back towards the equator as surface winds.

Question 12

What are ocean currents?

Answer 12

Ocean currents are large scale movements of water that transfer heat energy from warmer to cooler regions.

Question 13

What is an example of surface currents?

Answer 13

The gulf stream. It brings warm water from the Caribbean and keeps Western Europe warmer than it would otherwise be.

Question 14

What are surface currents and what causes them?

Answer 14

Surface currents are caused by winds and helps transfer heat away from the equator.

Question 15

How is a current created

Answer 15

Water freezes at the poles—> water gets saltier —> increased density.
Increased density —> sinks —> warmer water flows in at the surface.

Question 16

What is thermohaline circulation?

Answer 16

The cycle of cooling and sinking which moves water in a big loop around the earth.

Question 17

What causes variations in climate?

Answer 17

The pressure belt caused by global atmospheric circulation.

Question 18

How do Hadley and Ferrel cells create an arid climate?

Answer 18

The sinking air from the Hadley and Ferrel cells meeting causes high pressure and prevents rainfall. Therefore, there is low rainfall and temperatures are hot.

Question 19

How do the two Hadley cells create a tropical climate?

Answer 19

Rising air from the two Hadley cells meeting causes low pressure and lots of rainfall. Therefore, temperatures are hot all the time and rainfall is high.

Question 20

What creates a polar climate?

Answer 20

Sinking air from the Polar cells creates an area of high pressure at the poles. Temperatures are low all year round and there’s very little rainfall.

Question 21

What is climate change?

Answer 21

Climate change is any significant change in the Earth’s climate over a long period.

Question 22

What is the Quaternary period?

Answer 22

The most recent geological time period, spanning from about 2.6 million years ago to the present day.

Question 23

How long is the interglacial period usually?

Answer 23

10,000 years

Question 24

How long are the glacial periods usually?

Answer 24

100,000 years

Question 25

When did the last glacial period end?

Answer 25

Around 15,000 years ago.

Question 26

Define orbital changes?

Answer 26

Variations in the way the earth moves round the sun.

Question 27

What is the stretch (eccentricity)?

Answer 27

The path of the Earth's orbit around the sun.

Question 28

How does the stretch (eccentricity) impact the earth's orbit around the sun?

Answer 28

The path changes from an almost perfect circle to an elipse (oval) and back again about every 96,000 years.

Question 29

What are natural causes of climate change?

Answer 29

Orbital changes. Volcanic activity. Solar output. Asteroid collisions.

Question 30

What is the tilt?

Answer 30

The earth's axis is tilted at an angle as it orbits the sun.

Question 31

How often does the tilt change?

Answer 31

The tilt changes over a cycle of about 41,000 years.

Question 32

What is meant by the wobble?

Answer 32

The axis of the Earth wobbles like a spinning top.

Question 33

How often does it wobble?

Answer 33

On a cycle of about 22,000 years.

Question 34

How do orbital changes affect the climate?

Answer 34

The cycles affect the amount of solar radiation the Earth receives. If the Earth receives more energy, it gets warmer.

Question 35

How does volcanic activity cause climate change?

Answer 35

Major volcanic eruptions eject large quantities of material, e.g. ash, into the atmosphere. Some of these particles reflect the sun's rays back out to space, so the Earth's surface cools.

Question 36

How does solar output cause climate change?

Answer 36

The Sun's output of energy is not constant. When solar output is reduced, the Earth's climate may become cooler.

Question 37

What was the Maunder Minimum?

Answer 37

A period of reduced solar activity between 1645 and 1715.

Question 38

How do asteroid collisions cause climate change?

Answer 38

Asteroids hitting the Earth's surface can throw up huge amounts of dust into the atmosphere. These particles prevent the Sun's energy from reaching the Earth's surface so global temperatures fall.

Question 39

What are the three pieces of evidence for natural climate change?

Answer 39

Tree rings. Ice cores. Historical records.

Question 40

How do tree rings show how the climate has changed over time?

Answer 40

By looking at the thickness of the rings, scientists can see what the climate was like each year. When it is warmer, the rings are thicker.

Question 41

How do ice cores show how the climate has changed over time?

Answer 41

Ice sheets are made up of layers of ice. One layer is formed each year. By looking at the gases (e.g. carbon dioxide) trapped in the layers of ice, scientists can tell what the temperature was each year.

Question 42

How do historical records show how the climate has changed over time?

Answer 42

Historical records like diaries can show what the climate was like by giving the number of days of rain or snow and the dates of harvests (an early harvest suggests warm weather).