climates and biomes Flashcards
where is the equitorial climate found
5 degrees north and south from the equator
Characteristics of an equatorial climate
- Hot conditions ( usually above 26%)
- High levels of rainfall ( often over 2000mm per year)
- Rainfall mainly convectional and can fall on 250 days of year (Occurs frequently on days that are hot, in the afternoon at the same time of day)
- Lack of seasons
- Cloud cover varying ( being none in the morning and reaching cumulonimbus by afternoon)
- Very high humidities ( relative humidities of 100% being reached daily during the afternoon )
- Wind speeds are not very high because of the large amount of trees
- Low annual range of temperature ( 2 to 5 degrees)
- Diurnal range temperatures low ( 5 degrees)
- Annual distribution of rainfall, rains all year round
overall, the equitorial climate is
hot, humid, rainy, wet all year round
does the equitorial climate have seasons
no
FACTORS THAT AFFECT A PLACES CLIMATE (5)
latitude
proximity to sea
ocean currents
altitude
prevailing winds
how does proximity to sea affect climate
Distance from the sea is important as water takes up heat from the sea and emits it more slowly than land does. Coastal areas are cooler and wetter than inland areas. ( doesn’t affect equatorial)
does proximity to sea affect equitorial climate
NO
how does latitude affect climate
Locations with higher or lower latitude receive more or less sunlight and so can be hotter or colder( between 5d north and 5d south) ( affects equatorial)
does latitude affect equitorial climate
yes
how does ocean currents affect climate
If the ocean currents are warm than it is warmer and more humid and if the currents are cold the weather is cooler (doesn’t affect equatorial)
do ocean currents affect equatorial climate
NO
how does altitude affect climate
High-altitude areas usually experience cooler temperatures, more precipitation, strong winds, and
low air pressure and oxygen levels. In general air temperatures decreases with increasing altitudes.because air under the greater pressure of lower altitudes is denser and therefore warmer. As altitude increases so the pressure on the air is reduced and the air becomes cooler.
does altitude affect equatorial
NO
how do prevailing winds affect climate
The effect of wind on temperature depends on the characteristics of the wind.prevailing winds coming from the land lower the winter temperatures, but raise them in summer. This is because continental areas are very hot in summer but very cold in winter. Prevailing winds from the sea do the opposite; they lower the summer temperatures and raise them in winter.
If the winds come from the poles then they are cooler, if they come from the tropics they are warmer
WHY IS THE EQUATORIAL CLIMATE HOT
(2)
- The elevation of the sun is high because it is on the equator
- The sunrays are direct and more focused on the equator meaning these regions are hotter.
WHY IS IT RARELY VERY HOT IN THE EQUATORIAL CLIMATE
(3)
- Because there is so much cloud cover, a lot of the insolation is reflected and goes back into outer space
- Insolation- incoming solar rays
- Also because of day length, 12h of daylight and 12h of darkness
WHY IS IT HOT ALL YEAR ROUND IN EQUATORIAL CLIMATE
Because there are no seasons and the heat the land receives by the sun is almost the same throughout the year leading to no significant change in the climatic conditions of the region
The sun’s elevation is high all year round
Why is there a small diurnal range of temperature in the equatorial climate?
Because there are a lot of clouds that trap heat, less heat is lost at night meaning the diurnal range is low
TYPE OF RAINFALL ASSOCIATED WITH EQUATORIAL CLIMATE
convectional rainfall
how is convectional rainfall formed
Occurs frequently on days that are hot usually with cumulus clouds and thunder
Usually happens in the afternoon at the same time of day each day ( falls when the sun is hottest ( when it sets))
It becomes very humid as the moisture from ground evaporates
Because the air is in contact with a hot surface, the air becomes hotter and rises ( convection happens)
Once it rises it becomes cooler and the relative humidity increases ( once the air becomes saturated( 100% relative humidity)) condensation happens and clouds begin to form ( the convection currents keep the clouds and water particles up)
Once the currents stop ( when the sun starts to set, all the waterfalls ( once the sun sets it stops heating and the convection then stops so it starts to rain)
Heavy rainfall that doesn’t last long as it gets dumped and then the clouds go away during the evening
what is convectional rainfall
Heavy rainfall that doesn’t last long as it gets dumped and then the clouds go away during the evening
WHY DOES IT RAIN SO HEAVILY AND ALWAYS AT THE SAME TIME OF DAY ( USUALLY AFTERNOON) IN EQUATORIAL CLIMATE
Because the warmer air rises up and then expands, reaching a cooler layer and saturates them they then condense into clouds and the precipitation falls, this happens because the temperatures don’t vary a lot from day to day so this happens at the same time with the same temperatures every day.
Because the sun reaches its highest and hottest point at the same time every day and also sets so stops heating at the same time so the rain falls at that time
Once the sun sets, all the rain that was accumulated inside the clouds gets dropped in one go which is why it rains so heavily
what is the ITCZ
low pressure system that affects the equatorial climate
ITCZ stands for
ITCZ INTERTROPICAL CONVERGENCE ZONE
why is the itcz called a convergence zone
It is called a convergence zone because it is where winds from the northern hemisphere and the southeast hemisphere converge (come together) which creates uplift
WHY IS RAINFALL SPREAD QUITE EVENLY THROUGHOUT THE YEAR IN THE EQUATORIAL CLIMATE
It’s because it is affected by the ITCZ meaning when the ITCZ comes it brings heavy rainfall and thunderstorms. In some areas the ITCZ causes 2 periods of very heavy rainfall every year. One occurs when the ITCZ crosses these areas on its way north and another occurs when it crosses these areas again on its way south
the equatorial zone is always affected by the ITCZ ( low pressure) and so always has rain
Hot desert climate is
very sunny and has low rainfall
where are hot desert climates found
generally found between the tropics of cancer and capricorn (15-30 degrees north and south of the equator).
CHARACTERISTICS OF HOT DESERT CLIMATE
- Very hot days and cold nights, because of the lack of cloud cover
- Low and irregular amounts of rainfall, and also lack of any seasonal pattern
- Low levels of humidity for much of the year
-Warm and dry winds, that sometimes cause sandstorms
- Diurnal range 50 degrees , so extreme
Annual rainfall total is less than 250 mm of rainfall per year ( very low)
- HOTTEST MONTHS OF THE YEAR ARE REFERRED TO AS
THE HIGH SUN SEASONS
diurnal range in a hot desert climate is
extreme (50º)
annual rainfall in a hot desert climate
less than 250 mm of rainfall per year ( very low)
temperatures during the night and day in a hot desert climate
very hot during day, cold during night
WHY IS VERY HOT IN THE HIGH SUN SEASON (HDC)
Because the sun is at a direct angle, there is minimal cloud coverage and low humidity. This maximises radiation absorption which raises temperatures
WHY IS IT COOLER DURING THE LOW SUN SEASON (HDC)
because there is less direct sunlight and is less intense, the days are also shorter so there is less time for the desert to heat up and it cools quickly during the night because there’s no moisture to hold the heat.
WHY IS THERE A MODERATE ANNUAL RANGE IN TEMPERATURE IN HOT DESERT CLIMATES
Because of low humidity, the air doesn’t trap heat. There are clear skies so no clouds and the heat escapes easily in the nights. The sandy terrain doesn’t hold heat well so it cools quickly
WHY IS THERE SUCH A LARGE DIURNAL RANGE OF TEMP IN A HOT DESERT CLIMATE
The air is dry so during the day the dry air lets it get really hot and at night it cools down quickly because it doesn’t hold onto the heat.
Clear skies, without clouds, the heat escapes easily at night making it much c
What season is convectional rainfall more likely to occur in the hot desert climate and why?
During summer ( high sun season) because it’s when intense heat causes air to rise quickly that form clouds that bring rain.
What season is frontal rainfall more likely to occur in the hot desert climate and why?
During winter ( low sun season) when cold air moves in because it forces warm air to rise and form rain clouds
Frontal rainfall
occurs when a warm front meets a cold front. The heavier cold air sinks to the ground and the warm air rises above it. When the warm air rises, it cools. The cooler air condenses and form clouds. The clouds bring heavy rain.
subtropical high pressure system affects which climates
hot desert
Why does subtropical high pressure system lead to dry conditions ?
Because the sinking air prevents clouds and rain falls while dry air masses bring little moisture into the desert
why is humidity and rainfall so low in hot desert climate
Subtropical high-pressure system
The presence of it leads to sinking air, preventing cloud formation and precipitation
High evaporation rates
Intense heat causes high evaporation of moisture from surface, which reduces humidity levels
Rain shadow effect
Mountains surrounding hot desert regions block winds carrying moisture, resulting in reduced rainfall
WHERE ARE TROPICAL RAINFORESTS FOUND
Tropical rainforests are mainly found between 23 degrees north and south of the equator and mostly near the coast. In Africa, indonesia and central America
WHAT IS THE CLIMATE TYPE ASSOCIATED WITH THE TROPICAL BIOME
tropical climate
THE VERTICAL STRUCTURE OF THE TRF
composed of 5 structures
- emergent layer
- dense main canopy layer
- under canopy layer
- shrub layer
- ground level
emergent layer in TRF
reaches a height of 30-40 metres. (emergent trees are widely spaced)
main canopy layer in TRF
height of 20-30 metres.
under canopy layer TRF
of sapling trees is about 15 metres high. These occur only where light is available.
shrub layer TRF
there is a very sparse shrub layer in clearings, or where light is available)
ground layer TRF
there is a ground layer of tree ferns - but only in clearings and on river banks
WHY IS THE TRF DESCRIBED AS AN EVERGREEN FOREST
Because the forest isn’t seasonal, some trees will have flowers, other fruit, while some are losing their leaves.
Those trees drop their leaves at any time of the year, meaning the forest has an evergreen appearance
CHARACTERISTICS OF TREES FOUND IN THE TRFs (5)
Trees are very tall because they have to compete for sunlight
The bark is thin because they do not need protection from the cold
Their leaves are big because they need to catch the maximum amount of sunlight in the cloudy climate
Trunks are straight as competition from surrounding vegetation and lack of light forces the tree to grow straight up
They have large roots to keep them steady that are shallow and buttress
ADAPTATIONS OF TREES IN THE TRF BIOME (3)
Leaves have drip tips because they need to shed the torrential rain quickly and prevent them breaking off.
Trees take up nutrients through the roots,meaning that the shallow buttress roots allow the trees to access the nutrients near the surface of the soil. The roots are also essential for the stability of the very tall trees, which need their support in the wet and muddy soils.
Tropical soils are red because of the iron in them, when the trees grow, they absorb the nutrients in the soil and return them when the leaves fall. The leaves decompose quickly on the forest floors hot and wet conditions. This adds humus to the top of the soil.
CHARACTERISTICS OF TREES IN TRF
Trees are very tall because they have to compete for sunlight
Very high density of trees
Large variety of tree species
Their leaves are big because they need to catch the maximum amount of sunlight in the cloudy climate
Trunks are straight as competition from surrounding vegetation and lack of light forces the tree to grow straight up
They have large roots to keep them steady that are shallow and buttress
Straight, branchless, thich hardwood trunks
They have a crown with a dense layer of leaves
ADAPTATIONS OF THE TREES in a TRF (5)
Leaves have drip tips because they need to shed the torrential rain quickly and prevent the leaves from breaking off. (they get rid of weight of water to make trees more stable)
Trees take up nutrients through the roots,meaning that the shallow buttress roots allow the trees to access the nutrients near the surface of the soil. The roots are also essential for the stability of the very tall trees, which need their support in the wet and muddy soils.
There is dead organic matter, and because the conditions are wet bacterial action rapidly decomposes the matter turning it into food and nutrients for the trees and because there is so much water it creates a humus layer and leaching brings it further and deeper into the ground
They grow straight so they don’t waste energy and can focus on growing really tall instead ( for sunlight)
Produce massive leaves in order for tree to photosynthesize and produce fruit and reproduce
WHY IS THE BIODIVERSITY SO HIGH IN THE TRF BIOME
The hot and wet climate provides ideal conditions for many species of plants and animals to thrive.
So rich in biodiversity because it has been stable for 2 million years
Why are TRF soils usually so infertile?
Because the nutrients are absorbed by the trees when they grow and when the plant falls back down it is returned as a thin layer of hummus, but the deep layers of soil have few nutrients because of leaching ( nutrients taken down in solution and removed from soil by rainwater)
There will be soil erosion because of the amount of precipitation
Because of deforestation less trees have leaves that fall and less monkey poo falls creating a smaller/thinner layer of humus that ill also in turn have less nutrients
WHY ARE TRFs SO IMPORTANT TO NATURAL SYSTEMS
- They have a very high biodiversity
- They provide as a habitat for loads of animals and plants
- Are sources of food for animals and humans
- Really important for maintenance of soil fertility
- Climate change, are massive carbon sinks
WHY IS IT SO IMPORTANT TO CONSERVE THE TRFs
(4)
Biodiversity, its half the world’s species living there so the world would lose its biodiversity of animals and plants as they would become extinct
Biodiversity- they are rich in diverse species that offer potential resources for medicine, food and more things
Climate regulation- they act as carbon sinks, reducing greenhouse gas emissions and mitigating climate change
Ecosystem services - provide things like clean water, air purification, and soil stability. Benefiting local and global population. There are also people who have lived their for a long time so would be losing their culture and home
challenges for plants in a hot desert biome
Very hot
Lack of water
WHY ARE THE SOILS FOUND IN HOT DESERTS INFERTILE ?
Because they are usually rocky or sandy, so very porous meaning water passes through them very easily. Desert soils are also thin and contain very few plant nutrients. This is because very little organic matter is available to decompose into them.
ways vegetation has adapted in a hot desert biome
cacti - Have many long but deep roots to soak up as much water as possible after rain
shrubs - Their roots are shallow and wide-spreading to catch water after rain before it evaporates.
and flowering plants - light coloured petals to reflect sun
