Climate Flashcards
(35 cards)
Where are deserts located?
Between 5 - 30 degrees north + south of the equator.
- Outside tropical areas (eg. rainforests)
- In the rainshadow of mountain ranges
- Found inland on continents
- Cold ocean currents
Climate
The weather conditions prevailing in an area in general or over a long period
How are deserts formed? (high air pressure)
- Sunlight is most direct at the equator (meaning it is the warmest)
- Warm air rises and then condenses, forming clouds.
- Colder + denser air flows poleward (away from equator)
- As it moves it precipitates and loses its humidity.
- Once cool + less dense it sinks at approx. 30 degrees north/ south of the equator –> forming high air pressure
- The air warms up again by the sun, however, it has no moisture –> leading to extremely dry + hot deserts.
How are deserts formed? (rainshadows)
- Warm moist air moves across a coastal range
- It then reaches a mountain range and is forced up (increasing altitude)
- This causes it to cool + condense + form clouds + precipitate
- Once having passed over the mountain it continues to sink (with no moisture) + heats –> forming dry + hot deserts.
How are deserts formed? (Inland on continents)
- While moving across an ocean, air picks up moisture –> humidity
- When reaching land the moist air begins condensing + precipitating (however, no new moisture is being picked up)
- Eventually all moisture is removed from the air as wind travels inwards
–> Dry + hot air formed inland –> Deserts
How are deserts formed? (Cold ocean currents)
- Cold ocen winds meet warm land air –> Mositure condenses + fog formed.
- Thus moisture is removed from air and further inland a desert is formed.
(These currents are typically found on the west side of continents)
–> Why deserts form on the west side of continents (check with Miss Kappa)
Soil of hot desert
- Little vegetation in deserts –> barely any organic matter in soil
- Weathering (bc of strong winds not hindered by vegetation) creates deep deposits of sand + loose materials
–> Sand dunes can also form. - Soil can potentially bevery fertile bc important nutrients for plant growth (eg. calcium) haven’t been used up by vegetation.
- Topsoil is often baked by sun
Climate graph
Layered graph showing both rainfall + temperature across a year
Bar chart = rainfall
Line graph = Temperature
Sonoran desert
- Hot desert
- Located in subtropical region of North America (hot summer + mild winters)
- Has many saguaro cacti
- Summer temp = usually 40C + sometimes more than 48C
- High diurnal temperature range
- 75-500mm annual rainfall
- July - mid-September = summer monsoon (thunderstorms
- Bi-seasonal rainfall
Why the Sonoran desert formed
- High pressure air
- Rainshadow effect (air blows across pacific ocean + picks up msoiture. When the air hits the mountains on the Arizona-California border it precipitates
- Cold ocean currents (california current) cause desert to be formed inthe west side of the continent
Typical plant adaptations in the desert
Small leaves - Less water lsot from plant by transpiration (bc smaller surface area.
Tap roots - Long roots (7-10 metres long) that reach deep under ground to acess water supplies –> much longer + bigger than plant visible at surface.
Spines - (instead of leaves, eg. cacti) Spines lose less water than leaves + prevent animals from eating plant
Waxy skin - Reduces water loss by transpiration
Water storage - Eg. succulents store water + have waxy skin
Typical animal adaptations in deserts
- Nocturnal (bc cooler at night)
- Burrow underground (colder)
- Big ears to keep them cool
- Light-coloured coats –> reflect sunlight
- Diet/ food contains moisture (eg. seeds) not necessary to find as much water.
Tropical rainforest location
Along the equator + inbetween the tropics
- Main areas are northern South America (e.g. Amazon), Central Africa (e.g. Congo) and South East Asia.
Tropical rainforest climate - Characteristics
- Consistently high temperatures throughout the year – an average of about 25°C
- Annual temperature range: less than 5°C
- Rainfall – amount exceeds 2000mm
- Rainfall– seasonal distribution: fairly evenly distributed throughout the year
- Wind: low
- Cloud: heavy
- Humidity: high
- Pressure: low
- Little seasonal variation
What type of rainfall do rainforests typically recieve?
- Convectional rainfall
Sun’s energy heats surface of earth –> water evaporates + expands + rises –> cools 0 condenses –> Forms (cumulonimbus) clouds
What are the layers of the rainforest?
Highest
Emergent
Canopy
Under canopy
Shrub layer
Lowest
Emergent layer
The tops of all the tallest trees in the rainforest
Highest layer
Canopy layer
Where the upper parts of most trees are found.
The canopy is home to most life found in the rainforest.
3rd layer.
Under Canopy
Limited sunlight + saplings wiat here for the older plants to die –> there is then a space in the canopy which they can grow into.
2nd layer in the rainforest
Shrub layer
Due to the lack of light which reaches the forest floor –> There is very little vegetation between the trees.
What causes the soil fertility in the rainforest?
Nutrients recycling.
Rainforests are home to deciduous trees, meaning they lose their leaves over time. (not seasonally though)
These leaves get decomposed by the large amount of fungi living on the forest floor.
This creates an abundance of nutrients. However, this nutrients is quickly used up or else washed away by the heavy rainfall.
How many seasons do rainforests have?
2
One wetter season and one drier season.
Why are rainforests not suited for farming?
The fertility of the soil is dependent on the nutrients cycle.
By removing the vegetation, the cycle is disrupted and the soil becomes infertile.
Plant adaptations in the rainforest
Lianas –> use other plants to grow to sunlight.
Tree trunks –> tall + thin to reach sunlight. Bark = smooth to allow water to drip down to roots easily
Butress roots –> large roots + large surface area to support large tree
Epiphytes –> Live on other plants (more sunlight). Get nutrients from air + water –> not soil.
Drip tips –> pointy tips on leaves –> water easily runs off (instead of breaking plant)
Waxy leaves –> water easily runs off.