Extra Info

Question 1

Explain what is ITCZ

Answer 1

Inter-Tropical Convergence Zone

An area surrounding the equator where winds from the northern and southern hemisphere converge

Causing an area of low pressure with rainy conditions

Question 2

Describe the formation of ITCZ

Answer 2

= The Northeasterly trade winds and Southeasterly trade winds converge
= Create an area of lower pressure
= Moist air is forced up
= condenses forming a band of clouds and heavy precipitation
= Moves seasonally, the Earth tilts throughout the year
= causing patterns of precipitation to move with it
= causes wet seasons when ITCZ is over an area
= causes dry seasons when ITCZ has left that area

Question 3

Describe tilt as part of the Milankovitch cycle

Answer 3

= The tilt of the Earth’s axis changes from 21.5 degrees and 24.5 degrees
= Smaller the tilt, less variation between summer and winter
= Smaller the tilt, milder winter and cooler summer
The change takes around 41,000 years

Question 4

State the evidences for human climate change

Answer 4

1. global temperature rise
2. Sea Level rise
3. warming oceans
4. declining Arctic ice
5. increased extreme weather events

Question 5

Evidence for how human activity is causing climate change: sea level rise

Answer 5

Average global sea level risen by 20 cm since the 100 YEARS
Higher temperatures
Glaciers and ice sheets melt
Oceans and seas to thermally expand

Question 6

Evidence for how human activity is causing climate change: warming oceans

Answer 6

Tropical cyclones increase, more frequent
Flooding risk
Isle de Jean Charles fully submerged
Death of coral and sea creature species

Question 7

Evidence for how human activity is causing climate change: global temperature rise

Answer 7

The global temperatures are projected to increase by as much as 4 degrees by the end
of the century due to human activity (rising GHG in parts per million)
1880 –>2012 (+0.8 degrees)

Question 8

Describe in general a tropical cyclone

Answer 8

Warm oceanic water either side of the Equator begins to evaporate at the surface and air rises through convection, heavy with water vapour.
This leaves a low pressure area at the surface of the water, which sucks in more air from the surroundings.
As the air rises it begins to rotate, creating the eye wall, which is where the strongest winds are found
When the rising air reaches the top of the cyclone, the air flows away from the centre, leaving a layer of cirrus clouds that continue to spin
The air flowing away cools and sinks back to the ocean where the warm ocean water heats the air again, causing it to rise and continuing the cycle
The cyclical convection of warm, moist air results in bands of thunderstorm clouds on either side of the eyewall.
Air that sinks within the eye wall results in high pressure at the centre of the cyclone where calm, cloudless skies are found, known as the eye of the storm

Question 9

Structure of a tropical cyclone

Answer 9

Above tropical cyclones they have a dense canopy of cirrus clouds due to uplift of warm,
moist air as the cyclone is forming
Swirling around the centre of a cyclone are rain bands-these can stretch 1000km from
the centre of a cyclone
At the centre of the tropical cyclone is the eye (calm conditions), and around it is the eye
wall (strongest rainfall and winds) which can rise 15km into the atmosphere.
The eye is an area of high pressure as air falls, the eye wall is an area of intense
low pressure.

Question 10

Describe formation of a tropical cyclone

Answer 10

• Tropical storms form between approximately 5° and 30° latitude. Because of easterly winds they initially move westward.
• The air above the warm ocean is heated. Once the ocean water reaches at least 27°C, the warm air rises quickly, causing an area of very low pressure.
• As the air continues to rise quickly it draws more warm moist air up from above the ocean leading to strong winds.
• The rapidly rising warm air spirals upwards, cools, condenses and large cumulonimbus clouds form.
• These clouds form the eye wall of the storm and produce heavy rainfall.
• In the centre of the storm, cold air sinks forming the eye of the storm - here, conditions are calm and dry.

Question 11

How are volcanoes on hotspots formed

Answer 11

• magma rises towards earths surface due to the mantle plumes
• at the surface the magma erupts through the thin crust
• these volcanoes often rise above ocean surface to form island
• eg. Lanzarote