Paper 1 - Tropical storms

Question 1

Convectional rain formation

Answer 1

The sun heats the ground and the surface of water in lakes or seas.

Water on the surface evaporates (turns into water vapour).

The sun makes the air above the ground lighter (less dense), so it rises in convection currents.

Rising air cools, when it reaches the dew point, the water vapour in the air condenses forming cloud droplets

At the equator, rapid rising and cooling create tall thunderstorm clouds, called cumulonimbus.

when these cloud droplets become heavy, gravity forces them to release the water as intense tropical precipitation.

Question 2

Solar energy strikes the ground almost at a right angle

Answer 2

Solar energy (heat) is concentrated on a small area which is heated intensely

Question 3

Solar energy strikes the ground at a low angle

Answer 3

Solar energy (heat) is spread over a large area due to the curved surface of the earth with very little heating of the ground

Question 4

What factors affect worldwide variations in climate?

Answer 4

latitude
tilt of the earth and the curved surface of the earth diff areas experience diff concentrations of sun rays

Question 5

When a hemisphere is tilted towards the sun,

Answer 5

it experiences the summer season.

Question 6

When a hemisphere is tilted away from the sun,

Answer 6

it will experience the winter season.

Question 7

low pressure systems

Answer 7

• wet
• air rises so air is less dense
• precipitation here

Question 8

high pressure system

Answer 8

• dry
  -colder air = denser so sinks

Question 9

wind created by

Answer 9

Air moves between areas of high and low air pressure creating wind.

Question 10

Close to the equator, the ground is heated intensely.

Answer 10

• heats the air above.
• The warm air is less dense and rises in convection currents.
  = low air pressure

Question 11

The polar regions receive far less solar insolation.

Answer 11

This results in colder denser air sinking
= high air pressure.

Question 12

Low pressure air tends to move in an

Answer 12

anti-clockwise direction and leads to rain because rising warm air cools and the water vapour condenses.

Question 13

High pressure zones are characterised by low precipitation as

Answer 13

as sinking air warms preventing condensation.

Question 14

Hadley cell

Answer 14

Warm air rises at the equator creating a low pressure zone. The air spreads out towards the North and South Pole and cools. At approximately 30°s north and south the air sinks creating a high pressure zone. Air travels back towards the low pressure zone at the equator as trade winds.

Question 15

Ferrel cell

Answer 15

Air rises at approximately 60°s north and south creating a low pressure zone. The air moves towards the equator. At approximately 30°s north and south the air sinks creating a high pressure zone. The sinking air moves back towards the 60°s low pressure zone as westerly winds

Question 16

Polar cell

Answer 16

Cold dense air sinks a the poles creating high pressure. The air spreads out towards the equator and warms slightly. At approximately 60°s north and south the air rises creating low pressure, then the air moves back towards the poles.

Question 17

This is called the Coriolis Effect.

Answer 17

The Earth’s rotation causes air to slant towards the equator from a northeasterly direction in the northern hemisphere and from a southeasterly direction in the southern hemisphere.

Question 18

Westerlies form

Answer 18

in the subtropical high pressure zones, and flow from west to east, towards the poles, where there is low pressure.

Question 19

The trade winds

Answer 19

are the prevailing (dominant) surface winds that form in the high pressure sub-tropical zone and flow towards the low pressure tropical zone.

Question 20

Tropical Storms:

Answer 20

Low pressure systems close to equator
- form over the oceans
- travel in the direction of the trade winds.
- gain energy to travel further away from the Equator.

Question 21

Depressions:

Answer 21

follow the jet streams over the ocean and bring precipitation to coastal areas. Jet streams are narrow bands of strong winds.
- at 60 degrees not warm enough (not much energy)

Question 22

intertropical convergence zone (ITCZ).

Answer 22

The low pressure zone close to the equator

Question 23

Lattitude of tropical storms

Answer 23

5 and 30 N/S

Question 24

ocean temp

Answer 24

27 dgerees

Question 25

depth of ocean

Answer 25

60 to 70 m deep

Question 26

form in which season

Answer 26

summer and autumn

Question 27

wind shears should be

Answer 27

low
- to rise without being torn apart by wind

Question 28

weather features

Answer 28

low air pressure
strong winds
heavy rain

Question 29

northern hemipshere spin

Answer 29

west when forming
the anticlockwise

Question 30

southern hemisphere

Answer 30

west when forming
clockwise

Question 31

1: Air is heated above the surface of warm tropical oceans (at least 27°C). why

Answer 31

The warm air rises rapidly creating low-pressure

2: The rising air draws up more air and large volumes of moisture from the ocean, causing strong winds

Question 32

3: The Coriolis effect causes

Answer 32

the air to spin upwards around a calm central eye of the storm

Question 33

4: As the air rises

Answer 33

, it cools and condenses to form large, tall cumulonimbus clouds, which generate torrential rainfall. The heat given off when the water vapour condenses powers the tropical storm.

Question 34

5: Cold air sinks in the eye

Answer 34

, therefore there is no cloud, so it is drier and much calmer (no wind).

Question 35

when are storms categorised as tropical

Answer 35

6: When winds reach 74 mph / 119 kph, the storm is categorised as a tropical storm.

Question 36

7: The tropical storm travels west across the ocean

Answer 36

due to the prevailing wind (trade winds)

Question 37

8: As the eye of the storm approaches land,

Answer 37

the very low pressure and very strong winds create storm surges, sea water is pushed onto the land causing severe coastal flooding.

Question 38

9: When the tropical storm makes landfall

Answer 38

(moves over land) it loses its source of energy (cooling and condensing water vapour from the ocean) so it loses power and weakens

• friction slows it = changes direction

Question 39

structure of the storm

Answer 39

Winds increase in strength at the eye wall
B: Heavy rain and strong wind in the eye wall
C: Clear sky and no wind at the eye
D: Warm, moist air rises and is pulled towards the centre

Question 40

Features in northern hemisphere

Answer 40

Wind blows anticlockwise towards the centre

Question 41

Features in southern hemisphere

Answer 41

Wind blows clockwise towards the centre

Question 42

Features

Answer 42

Clearly visible calm eye
Very thick cloud making up the eye wall
Strongest winds around the eye wall, can be over 300 kms/h
Intense rain, heaviest close to the eye wall
Thinner and more broken cloud at edges, thicker towards the middle

Question 43

They bring - Air pressure

Answer 43

This starts low and continues to get lower creating a deep depression. It increases when the storm makes landfall.

Question 44

They bring - cloud cover

Answer 44

At the start of the storm formation, cumulus or stratus clouds form. As more moisture is drawn up and condenses these grow into towering cumulonimbus clouds. When landfall happens they start to dissipate

Question 45

Humidity

Answer 45

This increases as rising warm air evaporates and draws up more water vapour from the warm oceans. It remains high then reduces quickly when the tropical storm reaches dry land.

Question 46

Precipitation

Answer 46

This begins the moment the weather forms an established low pressure system. Rapid cooling and condensing of water vapour means it gets heavier and heavier, until the storm reaches landfall, when the intensity starts to decrease.

Question 47

wind speeds

Answer 47

This increases due to the rate of evaporation and condensation. Must reach 74 mph / 119 kph before being classified as a tropical storm. Decreases rapidly when the storm reaches land.

Question 48

The frequency of tropical storms might

Answer 48

more frequent as oceans warm

Question 49

The intensity / strength of tropical storms might

Answer 49

increase as more energy

Question 50

The distribution of tropical storms might

Answer 50

warmer oceans = more further N/S

Question 51

What are the effects of tropical storms
Primary effects

Answer 51

People killed or injured by flying debris (wind) or more commonly by drowning
Buildings including homes and businesses destroyed by strong winds or storm surges (flooding)
Transport and communication links disrupted due to flooding by rain or storm surges
Water supplies are contaminated by sea water, sewage or industrial waste
Energy supplies cut off as power lines blown down
Food shortages if crops / livestock killed
Crops destroyed by strong wind or storm surges
Landslides occur after intense rainfall, up to 500 mm in 24 hours
Many aquatic species like fish are killed by polluted water sources, e.g. sewage leaks from poor sanitation
Businesses lose income due to loss of communications and transport
Waterborne diseases spread
Governments struggle with debt due to rebuilding costs
Homelessness rises during rebuilding
Unemployment increases and GNI decreases as businesses are lost
Trees uprooted by wind, forests are destroyed by strong wind or storm surges
Food webs become disrupted and biodiversity decreases

Question 52

Secondary effects

Answer 52

Businesses lose income due to loss of communications and transport
Waterborne diseases spread
Governments struggle with debt due to rebuilding costs
Homelessness rises during rebuilding
Unemployment increases and GNI decreases as businesses are lost
Trees uprooted by wind, forests are destroyed by strong wind or storm surges
Food webs become disrupted and biodiversity decreases

Question 53

What are more significant, primary or secondary effects?

Answer 53

• widespread flooding
• huge damage to buildings and infrastructure.
  = deaths
  Death rates can be minimised with evacuation orders but in NEEs and LICs vehicles to evacuate may not be available and appropriate evacuation centres might not be provided.

Difficult to protect properties and infrastructure against storm surges.

Secondary impacts can be countered by immediate responses by governments and charities.

Question 54

Immediate responses

Answer 54

As tropical storms approach a coastline, governments issue warnings about wind, rain and storm surges, so people can attempt to protect their homes
As tropical storms approach, governments issue evacuation orders, instructing people to move away from the coast, to protect people from flooding.
Emergency shelters are opened up, away from the coast on higher land
Emergency services ( e.g. ambulances / search and rescue teams) sent out
Bottled water and emergency food aid distributed
Tents are provided, often by international aid, to house people whilst rebuilding takes place
Emergency repairs to sanitation or temporary toilets provided

Question 55

Long term responses

Answer 55

Buildings repaired or rebuilt
Roads are reconstructed
Governments might invest in new methods of protection and prediction e.g. an early
warning system for storm surges or sea defences to reduce flooding
Governments try to build back better and may change planning rules and create no build zones along the most vulnerable sections of coastline

Question 56

What are more important, immediate and long term responses?

Answer 56

Individual responses e.g. boarding windows have far less impact than government responses.

Both immediate and long term responses are equally important.

Immediate responses protect lives and reduce spread of disease, longer term responses focus on improving prediction and protection to save lives and reduce economic impacts in future.
Success of governments long term responses is often limited by wealth.
Some poorer NEEs e.g. Bangladesh have very successful long term responses e.g. sophisticated tracking systems, cyclone shelters and sea defences that save many lives

Question 57

Monitoring of storms and storm prediction

Answer 57

Supercomputers are used to model hurricane paths. They can give a 5 day warning of a hurricane hitting land accurate to 400 km using a track cone. Around 70% of hurricanes occur within the predicted track cone. Early prediction gives time for governments to issue evacuation orders and people time to evacuate and protect their homes and businesses, e.g. by boarding up windows.

Evacuation orders can save hundreds of thousands of lives

National Hurricane centres around the world issue early warnings of hurricanes so people have time to prepare to evacuate. Not all people evacuate though as it is costly and time consuming. Not all people can afford to evacuate (need a vehicle) or have anywhere to go. LICs and NEEs may not be able to build shelters and provide emergency supplies for large numbers of people or provide vehicles to evacuate people.

Despite advances in scientific methods, accurate prediction is not always
easy because the strength and path of a tropical storm can change quickly,
and the cone of uncertainty is large.

Question 58

Protection

Answer 58

Protection
Buildings can be reinforced to withstand damage caused by the very strong winds during tropical storms e.g. by using reinforced concrete. Buildings can
also be put on stilts so they’re safe from floodwater. People in the USA are advised to install hurricane straps to secure roofs of houses, install storm shutters to protect windows, and install an emergency generator (for electricity). This reduces property damage and means important appliances e.g. lighting, phone chargers etc can operate.
In some lower income countries e.g. Bangladesh storm shelters are common and can ensure the survival of whole villages.
The raised area at the base is to offer some protection for peoples livestock

Shelters have been very effective at reducing large death tolls in countries like Bangladesh
Land can also be protected by ensuring low land at the coast is not built on and by using coastal flood defences such as seawalls and levees which hold back sea water and reduce the impacts of tropical storms. Very expensive if coastline is very long
Wetlands and mangrove forests at the coast can help protect against storm surges by reducing the waves energy. This protects coastal settlements. These natural habitats need to be protected and maintained if they are damaged by storm conditions. Cheaper than sea walls, not as effective

Question 59

Planning and preparation

Answer 59

Planning and preparation
Governments can plan and prepare for tropical storms by building cyclone shelters or designate suitable buildings as evacuation centres and educate the population about these.
Governments can stockpile supplies of emergency food, water, medicines and tents as emergency shelter

Individuals can plan and prepare for tropical storms by
Preparing a disaster supply kit with emergency food, water, first aid
Knowing where the emergency evacuation shelters are
Planning with the family what to do in a hurricane emergency
Storing loose items or tying items in the garden down