EGS Frank Week 1 Tropical & Subtropical Flashcards
Where are the tropics & where are the subtropics?
- Tropics: region btwn ~ 23.5 ° N & S of the Equator (tropics of cancer & Capricorn)
- Periphery of the tropics, & subtropics: located from ~ 23.5 ° to ~35-40 ° N & S
Account for the tropical and subtropical distribution of rainfall. Both in space and time P1:
* Influenced by a)_ and b) , such as c) and d)_
- Influenced by a) global atmospheric pressure & b) circulation patterns, such as c) the ITCZ (Intertropical Convergence Zone) and d) the Hadley Cell Circulation.
Account for the tropical and subtropical distribution of rainfall. Both in space and time P2:
- Rainfall distribution (spatially & temporally) is a)
- Most regions closest to/along the equator receive b) . They are also known as the c) . This is due to the d) _______________.
- d) is e ) ____________________________ which f) ________________________, producing g) ________________, resulting in h) ________________ whilst the air then i) ____________________ to and in the j) creating k) _.
- Rainfall distribution (spatially & temporally) is a) incredibly varied throughout the Tropics
- Most regions closest to/along the equator receive b) high rainfall nearly all year round. They are also known as the c) Humid tropics. This is due to the d) the presence of the ITCZ (intertropical convergence zone)
- d) The ITCZ is a e) low pressure belt of converging trade winds which f) ** accumulate moisture & heat up as they travel** producing g) warm, moist air which rises, resulting in h) frequent, heavy rainfall, whilst the air then i) cools and descends to and in the j) subtropics creating k) high pressure conditions (colder, low rainfall)
Account for the tropical and subtropical distribution of rainfall. Both in space and time P3:
- These regions are known as the a)______.
- This is part of the b) _____________.
- Rainfall becomes more c) _ further from the eqautor.
- This is because the d) _ migrates e) _ and f) _ .
- Therefore, at the periphery of the tropics, rainfall distribution has a g)_.
- These regions are known as the a) Arid Subtropics
- This is part of the b) Hadley Cell Circulation Pattern
- Rainfall becomes more a) seasonal further from the equator.
- This is because b) the ITCZ migrates c) northward during the northern hemisphere summer (around July) and d) southward during the southern hemisphere summer (around January).
- Therefore, at the periphery of the tropics, rainfall distribution has a e) more pronounced seasonality
What are the causes:
(6)
- ITCZ
- Hadley Cell Circulation
- Distance from Ocean
- Topography
- Temp of Ocean Currents (SSTs)
- ENSO
What are the causes:
(3) Distance from Ocean
4 bullet points
- Air in the tropics tends to move from E to W, getting dryer as it moves
- Thus limiting the moisture availability and thus rainfall
- (Arid regions tend to be located further away from the ocean).
- (e.g. Asian & North American deserts).
What are the causes:
(4) Topographical Influences
2 bullet points
- Mountain ranges can result in a rain shadow effect wherein warm, moist air rises on the windward side resulting in rainfall but blocking the leeward side from receiving conditions favouring precipitation
- (e.g. Atacama Desert & Andes Mountains)
What are the causes:
(5) Temp of Ocean Currents (SSTs)
2 bullet points
- Cold ocean currents hinder evaporation, resulting in dry air and limiting rainfall
- (e.g. Benguela current & Namib Desert).
What are the causes:
(6) ENSO (El Nino- Southern Oscillation – inter annual anomaly)
- Tends to produce (), disrupting the ().
- With El Nino resulting in () in () -> the trade winds () altering the ().
- Under normal conditions, () rises in the () , whilst () sinks in the ().
- During El Nino, _:
- () rises in () -> () along ().
- () sinks in () -> () in () such as a), b) & c)
- Tends to produce drier or wetter conditions than usual, disrupting the spatial & temporal distribution of rainfall.
- With El Nino resulting in warmer SSTs in central & eastern Pacific ocean -> the trade winds weaken/reverse, altering the Walker Circulation pattern
- Under normal conditions, warm, moist air rises in the Western Pacific (near Southeast Asia and Australia), whilst cool, dry air sinks in the Eastern Pacific (near South America).
- During El Nino, this pattern shifts:
- Warm, moist air rises in the Central & Eastern Pacific (near South America) -> increased rainfall along the Eastern tropical Pacific
- Cool, dry air sinks in the Western Pacific (near Southeast Asia) -> reduced rainfall & drought in humid tropical regions such as a) Indonesia, b) the Philippines, & c) northern Australia.
What are the causes:
(6) ENSO (El Nino- Southern Oscillation – inter annual anomaly) P2:
- With La Nina, ________________:
- Trade winds () ->
- This leads to () in () & () in () -> () & () along ().
- With La Niña, the “normal” Walker Circulation is enhanced:
- Trade winds strengthen, -> pushing even more warm water westward.
- This leads to above-average rainfall in the Western Pacific (e.g., Southeast Asia & northern Australia) & strong cold water upwellings in the Eastern Pacific -> cooler SSTs & drier conditions along South America’s coast
How does this relate to distribution of Arid and humid tropics?
2 points
- Humid tropics tend to be distributed near/around the equator
- Whilst arid tropics tend to be distributed further from the equator, closer to the periphery of the tropics.
Desert Climate Characteristics (P1):
1. L
2. D
3. G
- receive Less than 300mm of rainfall per year
- Distinct rainy season
- Great rainfall spatial gradient (patches of rain, very localised)
Desert Climate Characteristics (P2):
(4) F
(5) A
(6) C
(4) Few rainy days per year
(5) Annual average may fall in a day (variability)
(6) Cool nights/ Hot days
Desert Climate Characteristics (P3):
(5) S
(6) H
(7) A
(8) G
(5) Signific. temp ranges/variations -> dew supplementation
(6) High deserts receive snow & coastal ones may receive fog
(7) “Average rainfall is the total that never falls”
(8) Great interannual variability
Humid Climate Characteristics (P1):
1. L
2. I
3. S
4. A
- Low pressure area (LP cells dominate?)
- ITCZ, intertropical trough, tropical confluence
- Some rain almost all year round
- Amazon receives 5mm rain per day
Humid Climate Characteristics (P2):
(5) S
(6) S
(7) C
(8) 2
(9) 1
(5) Some seasonal rain variability
(6) Short dry season
(7) Cyclones & Hurricane storms
(8) 2000-4000 mm per annum
(9) 11000mm possible (e.g. Northern India)
Where are the World’s deserts?
Asia:
1. K in () & ()
2. T in () & ()
3. T in ()
4. G in () & ()
* (side point)
- Karakum (297k km²) in Kazakhstan & Turkmenistan
- Thar (466k km²) in Pakistan & India
- Taklamakan (327k km²) in China
- Gobi (1.3Ma km²) in Mongolia & China)
- Developing Deserts, Loess soil, Soil Erosion
Where are the World’s deserts?
Australia:
1. G
2. G
3. G
4. S
- Great Sandy (340k km²)
- Gibson (156k km²)
- Great Victoria (338k km²)
- Simpson (145k km²)
Where are the World’s deserts?
North Africa:
1. () Region - 5
2. () Side - 5
3. S
- Sahel Region - Senegal, Mali, Burkina Faso, Niger, Nigeria, etc.
- Mediterranean side: Mauretania, Morocco, Algeria, Tunisia, Libya, etc.
- Sahara Desert - 9Ma km² (largest)
Where are the World’s deserts?
Middle East
- A
- Countries: 4
- Arabian Desert - 2.3Ma km²
- Jordan, Syria, Saudi Arabia, Gulf States, etc.
Where are the World’s Deserts
South America:
* Countries: 3
* Deserts:
- Countries: Argentina, Chile & Peru
- Deserts:
1.Patagonia (670k km²)
2.Atacama (105k km²) - driest
Where are the World’s Deserts
North America:
* Countries: 2
* Deserts:
- Countries: USA & Mexico
- Deserts:
1. Mojave & Sonoron (140k km²)
2. Chihuahua (518 km²).
Where are the World’s Deserts
Southern Africa:
* Countries: 3
* Deserts:
- Countries: South Africa, Botswana, Namibia
- Deserts:
1. Namib (150k km²)
2. Kalahari (712 250 km²)
3. Karoo (300k km²)
Where are the World’s rainforests
- Amazon -
- Congo-
- South East Asia -
- South America
- Africa
- Indonesia, Malaysia
