Atmosphere Flashcards
1
Q
- What is the name, origin, characteristics and explanation of the TROPICAL CONTINENTAL?
A
-
NAME:
➞ Tropical Continental (cT)
↳ (aka. HARMATTAN) -
ORIGIN:
➞ Sahara Desert -
CHARACTERISTICS:
1. very hot
2. low precipitation
3. stable air
4. low humdity -
EXPLANATION:
➞ It is hot as it forms over the tropics.
➞ As it forms over land (a desert)
↳ there are low levels of evaporation (dry and stable air mass)
2
Q
- What is the name, origin, characteristics and explanation of the TROPICAL MARITIME?
A
-
NAME:
➞ Tropical Maritime (mT)
↳ (aka. SOUTH WEST MONSOON) -
ORIGIN:
➞ Gulf of Guinea -
CHARACTERISTICS:
1. hot
2. high precipitation
3. unstable air
4. high humdity -
EXPLANATION:
➞ It forms over the equator,
↳ so has high temperatures, causing high levels of evaporation
➜ creating a moist unstable air mass.
3
Q
- As a result of the ITCZ, the rainfall varies across (Africa). e.g➜
A
-
North is very dry
➞ with a much wetter south. -
North has a clear wet/dry season
➞ whereas the south has rainfall all year round. -
South has 2 peaks
➞ whereas the other areas have only 1 peak.
↳ The 2nd peak is lower than the 1st. -
South’s peak rainfall is earlier in the year,
➞ than the north.
4
Q
- What is the reason for this varying rainfall across (Africa) due to the ITCZ?
A
- The ITCZ
➞ is an area of low pressure, where the trade winds meet. - A band of rainfall
➞ is created where the 2 air masses meet
↳ pushing the tropical maritime air up, cooling and condensing to form clouds and rain. - The 2 precipitation peaks
➞ can be attributed to the ITCZ moving north in the early part of the year and then south later in the year.
↳ This is due to the movement of the THERMAL EQUATOR. - The second peak is lower
➞ as water has been lost on the journey northward. - The south is influenced by the tropical maritime
➞ for most of the year. - The north is influenced by the tropical continental
➞ for most of the year. - The north’s peak is lower
➞ as it is further from the source of water.
5
Q
- What are the key points about the solar energy budget?
A
- Only 50% of the Sun’s energy reaches the Earth’s surface, due to:
* Deflection by atmosphere
* Absoprtion by the atmosphere
* Deflection by surface (ALBEDO EFFECT) - The Earth is heated by energy from the Sun. This is called INSOLATION/RADIATION.
6
Q
- What is the process of the solar energy budget?
A
- The atmosphere
➞ reflects 25%
↳ (e.g. gases [5%], water vapour + dust + cloud [20%])
➜ (the role of clouds will vary as the amount of cloud cover will vary) - The atmosphere
➞ absorbs 20%
↳ (e.g. clouds [3%]. gases + water vapour + dust [17%])
➜ (the role of clouds will vary as the amount of cloud cover will vary) - The surface
➞ reflects 5%
↳ through the ALBEDO EFFECT (snow, ice and water) - This then leaves only 50% of the initial solar energy to be absorbed by the Earth’s surface.
7
Q
- What are the key points about energy surplus and energy deficit?
A
- The Earth’s atmosphere
➞ is powered by DIFFERENTIAL HEATING of the Earth’s surface - So differential heating
➞ means the tropics (30°N - 30°S) are hot (ENERGY SURPLUS) and the poles (90°N - 90°S) are cold (ENERGY DEFCIT)
8
Q
- Why does the energy surplus and energy deficit occur?
A
- This happens because:
-
Greater curvature of the Earth at the poles
➞ causes energy to travel through a greater depth of atmosphere at poles
↳ so more reflection + absorption by clouds, dust, gas and water vapour
➜ so colder as less energy reaches the surface. -
Less curvature of the Earth at the tropics
➞ so rays heat a smaller area of earth
↳ so energy is more concentrated = more heat. -
Less curvature of the Earth at the tropics
➞ so rays hit vertically at tropics
↳ so there is a higher concentration of solar energy = more energy and heat. -
Snow and ice at poles
➞ means higher albedo effect as there is more reflection
↳ reducing solar energy. -
Lower albedo effect at the tropics
➞ as rainforests absorbing solar energy
↳ due to darker colours. -
Tilt of Earth
➞ creates seasons with shorter days in winter at the poles
↳ as further from the Sun meaning less solar energy
➜ but lack of seasons at tropics means same energy all year round.
9
Q
- How does the system of atmospheric distribution work?
A
- Through the 3 cells and associated winds,
➞ warm air from the Equator is moved to higher/cooler latitudes
↳ and cold air from the Poles is moved to lower/warmer latitudes. - Warm air rises at the Equator (0°)
➞ creating low pressure and travels 30°N.
↳ The air cools and sinks,
➜ creating high pressure. - Some of the air returns to the Equator (0°)
➞ as the NE trade winds
↳ and completes the Hadley Cell. - This happens as air moves from high to low pressure.
- The NE trade winds + other surface winds
➞ travel at an angle. - This happens as it is deflected by the Coriolis Effect.
10
Q
- How are heat and cold transferred in the oceans?
A
- Heat and cold are transferred by ocean currents
➞ with the warm and cold currents forming circular patterns called ‘GYRES’.
11
Q
- How do ocean currents work in the North Atlantic?
Currents ➜ Wind ➜ Flow ➜ Water
A
1.) Currents follow loops or gyres,
➞ These flow clockwise in the Northern Hemisphere.
↳ This is due to the Coriolis Effect which is caused by the spinning of the Earth.
2.) The warm currents
➞ flow North from the Equator to the Poles (e.g. North Atlantic Drift)
The cold currents
➞ flow South from the Poles to the Equator (e.g. Labrador current)
3.) This flow
➞ is helped by the prevailing surface wind,
↳ with energy being transferred by friction to the ocean currents.
4.) The circular flow
➞ is aided by differential heating
↳ creating density differences that occur in water.
➜ This results in the colder heavier water sinking and spreading out towards the Equator.
5.) This causes the lighter warmer water to be displaced towards the Poles.
6.) The pattern of ocean currents
➞ is also affected by land masses which divert them.
