Edexcel GCSE Geography notes
,Climate of a Tropical Rainforest:
Mean Temperature: 28 degrees – there are no seasons in the rainforest so the
temperature stays fairly constant throughout the year.
Hottest month / temperature: August to November 29 degrees
Coldest month / temperature: April 27 degrees
Temperature range: 2 degrees
Rainfall distribution: rainfall is evenly distributed throughout the year due to low pressure
at the equator
Mean Rainfall: 175mm
Highest month / ly rainfall: March 300mm
Lowest month / ly rainfall: August 41mm
Rainfall Range: 259mm
Cloud Formation: Low pressure at the equator caused by the meeting of the Hadley Cells,
clouds start to form at midday and thunderstorms around noon
Humidity: The amount of moisture in the air (%) Humidity is always very high
Factors that affect the climate:
Global distribution of rainforests:
Tropical Located near the equator. Fifty seven percent of all tropical rainforests are
rainforests found in Latin America. One third of the world's tropical rainforests are in
Brazil. Other tropical rainforests are located in Southeast Asia and the Pacific
Islands (25% of the world's tropical rainforests) and West Africa (18%)
Temperate Found along some coasts in temperate zones. The largest temperate
rainforests rainforests are found on the Pacific coast of North America. They stretch from
Oregon to Alaska for 1,200 miles. Smaller temperate rainforests can be found
on the southeast coast of Chile in South America. There are a few other
coastal strips with temperate rainforests, including small areas in the United
Kingdom, Norway, Japan, New Zealand, and southern Australia.
Latitude: the angular distance of a place north or south of the earth's equator
The rainforests are located near the equator and between the tropics at latitudes between O
and 23 degrees N or S. The sun is directly overhead here and so the rays are concentrated
on a very small area so which heats up very quickly. The sun’s ray’s travel through a small
amount of atmosphere therefore allows more insolation (solar radiation) to reach the
surface and very few of them are reflected back out to space.
, Distance from the sea:
As the land heats up more quickly during the summer and cools down more rapidly in the
winter than the sea, then places towards the centre of continents will have warmer
summers and colder winters than those with a coastal location
Prevailing winds:
The prevailing wind is the most frequent wind direction a location experiences. In Britain the
prevailing wind is from the south west, which brings warm, moist air from the Atlantic
Ocean. This contributes to the frequent rainfall. When prevailing winds blow over land
areas, it can contribute to creating desert climates.
Ocean Currents:
Warm currents tend to raise winter temperatures while cold currents usually lower summer
temperatures
Altitude:
Locations at a higher altitude have colder temperatures. Temperature usually decreases by
1°C for every 100 metres in altitude.
Types of Rainfall:
Frontal Rainfall: occurs when two air masses meet,
one a warmer mass and one a colder mass
1. The lighter less dense, warm air is forced to rise
over the more dense cold air
2. This causes the warm air to cool and begin to
condense
3. As the warm air is forced to rise further
condensation occurs and rain is formed
4. Frontal rain produces a variety of clouds which
bring moderate heavy rain fall
, Relief Rainfall: occurs when the prevailing wind picks
up moisture from the sea as they travel across it
making the air moist
1. The moist air reaches the coast and is forced to
rise over mountains and hills
2. This air then cools and condenses forming
clouds
3. The air continues to be forced over the
mountains so it drops its moisture as relief rain
4. Once over the top of the mountain the air will
usually drop down the other side warming as it
does so this means it has a greater ability to
carry moisture so there is little rain on the far
side of the mountain. This area is called the rain
shadow Rainfall: occurs in areas where the
Convectional
ground is heated by the hot sun
1. The surface of the earth is heated by the sun
2. The warm surface heats the air above it. Hot air
always rises so this newly heated air does so
3. As it rises air cools and begins to condense
4. Further rising and cooling causes large amounts
of condensation to occur and rain is formed
5. Convection tends to produce towering
cumulonimbus clouds which cause heavy rain
and thunder and lightning
Characteristics of tropical vegetation in the rainforest:
The forest structure is split into five tiers.
The emergent layer
reaches a height of 30-40
metres. Emergent trees
are widely spaced
The dense canopy layer is
at a height of 20-30
metres
The under canopy of
sapling trees is about 15
metres high. These occur
where light is available
There is a very sparse
shrub layer in clearings,
or where the light is
,Climate of a Tropical Rainforest:
Mean Temperature: 28 degrees – there are no seasons in the rainforest so the
temperature stays fairly constant throughout the year.
Hottest month / temperature: August to November 29 degrees
Coldest month / temperature: April 27 degrees
Temperature range: 2 degrees
Rainfall distribution: rainfall is evenly distributed throughout the year due to low pressure
at the equator
Mean Rainfall: 175mm
Highest month / ly rainfall: March 300mm
Lowest month / ly rainfall: August 41mm
Rainfall Range: 259mm
Cloud Formation: Low pressure at the equator caused by the meeting of the Hadley Cells,
clouds start to form at midday and thunderstorms around noon
Humidity: The amount of moisture in the air (%) Humidity is always very high
Factors that affect the climate:
Global distribution of rainforests:
Tropical Located near the equator. Fifty seven percent of all tropical rainforests are
rainforests found in Latin America. One third of the world's tropical rainforests are in
Brazil. Other tropical rainforests are located in Southeast Asia and the Pacific
Islands (25% of the world's tropical rainforests) and West Africa (18%)
Temperate Found along some coasts in temperate zones. The largest temperate
rainforests rainforests are found on the Pacific coast of North America. They stretch from
Oregon to Alaska for 1,200 miles. Smaller temperate rainforests can be found
on the southeast coast of Chile in South America. There are a few other
coastal strips with temperate rainforests, including small areas in the United
Kingdom, Norway, Japan, New Zealand, and southern Australia.
Latitude: the angular distance of a place north or south of the earth's equator
The rainforests are located near the equator and between the tropics at latitudes between O
and 23 degrees N or S. The sun is directly overhead here and so the rays are concentrated
on a very small area so which heats up very quickly. The sun’s ray’s travel through a small
amount of atmosphere therefore allows more insolation (solar radiation) to reach the
surface and very few of them are reflected back out to space.
, Distance from the sea:
As the land heats up more quickly during the summer and cools down more rapidly in the
winter than the sea, then places towards the centre of continents will have warmer
summers and colder winters than those with a coastal location
Prevailing winds:
The prevailing wind is the most frequent wind direction a location experiences. In Britain the
prevailing wind is from the south west, which brings warm, moist air from the Atlantic
Ocean. This contributes to the frequent rainfall. When prevailing winds blow over land
areas, it can contribute to creating desert climates.
Ocean Currents:
Warm currents tend to raise winter temperatures while cold currents usually lower summer
temperatures
Altitude:
Locations at a higher altitude have colder temperatures. Temperature usually decreases by
1°C for every 100 metres in altitude.
Types of Rainfall:
Frontal Rainfall: occurs when two air masses meet,
one a warmer mass and one a colder mass
1. The lighter less dense, warm air is forced to rise
over the more dense cold air
2. This causes the warm air to cool and begin to
condense
3. As the warm air is forced to rise further
condensation occurs and rain is formed
4. Frontal rain produces a variety of clouds which
bring moderate heavy rain fall
, Relief Rainfall: occurs when the prevailing wind picks
up moisture from the sea as they travel across it
making the air moist
1. The moist air reaches the coast and is forced to
rise over mountains and hills
2. This air then cools and condenses forming
clouds
3. The air continues to be forced over the
mountains so it drops its moisture as relief rain
4. Once over the top of the mountain the air will
usually drop down the other side warming as it
does so this means it has a greater ability to
carry moisture so there is little rain on the far
side of the mountain. This area is called the rain
shadow Rainfall: occurs in areas where the
Convectional
ground is heated by the hot sun
1. The surface of the earth is heated by the sun
2. The warm surface heats the air above it. Hot air
always rises so this newly heated air does so
3. As it rises air cools and begins to condense
4. Further rising and cooling causes large amounts
of condensation to occur and rain is formed
5. Convection tends to produce towering
cumulonimbus clouds which cause heavy rain
and thunder and lightning
Characteristics of tropical vegetation in the rainforest:
The forest structure is split into five tiers.
The emergent layer
reaches a height of 30-40
metres. Emergent trees
are widely spaced
The dense canopy layer is
at a height of 20-30
metres
The under canopy of
sapling trees is about 15
metres high. These occur
where light is available
There is a very sparse
shrub layer in clearings,
or where the light is
