1.1 Atmosphere Flashcards
Global Heat Budget
Curvature: Sun’s rays are less concentrated towards the poles due to curvature of earth, spreading heat energy over a larger surface area
Sun’s rays are more concentrated towards the tropics due to insolation being greater because rays strike vertically
Atmosphere: At poles, sun’s rays have more atmosphere to travel through, which increases the concentration of sun being reflected back
At tropics, sun’s rays have less atmosphere to travel through, so less energy is lost through reflection which increases absorption
Albedo: Albedo rates increase at poles due to surface types such as fresh snow reflecting 0.95 of all light energy
Albedo rates decrease at tropics due to surface types such as desert sand reflecting 0.15 of all light energy
Tilt: Tilt of Earth at poles causes sun’s rays to spread energy over larger area, resulting in long periods of cold darkness
Tilt of Earth causes tropics to receive direct sunlight, resulting in consistently warm temperatures
Atmospheric circulation- redistribution of energy
In the Northern Hemisphere, winds are deflected to the right because of Earths rotation
Warm air is distributed to higher latitudes and cold air is distributed to lower latitudes
Hadley Cell is formed when warm air rises at the equator which creates low pressure
Warm air then moves towards the poles before cooling and sinking at the tropics which creates high pressure
The Trade Winds move the air back to the equator which forms the Hadley Cell
Polar Cell is formed when cold air sinks at the poles which creates high pressure
The Polar Easterlies moves the cold air towards the equator which meets warmer air and rises
The air moves back to the poles which forms the Polar Cell
Ferrell Cell is between the Hadley Cell and Polar Cell at 30° and 60° North and South
It transfers air between the Hadley Cell and Polar Cell which creates the westerlies
Oceanic circulation- redistribution of energy
Ocean currents follow loops which flow clockwise in the Northern Atlantic
Oceans move water from areas of surplus at the equator to areas of deficit at the poles
This movement of warm and cold water helps to maintain the energy balance
Ocean currents in the Atlantic are moved by prevailing winds
Easterlies direct the Equatorial Currents and Westerlies direct North Atlantic Drift
The Coriolis Effect directs ocean currents to the right in the Northern Hemisphere and to the left in the Southern Hemisphere
Ocean currents are moved by the deflection off landmasses
The Equatorial Current is moved North and South of the equator when colliding with South America
Cold ocean currents are more dense and sink while warm ocean currents rise
This creates a conveyer belt effect which moves energy towards the poles
ITCZ- cause, characteristics, impact
ITCZ is the area of low pressure where the air masses meet
ITCZ moves north in July and south in January as it follows the Thermal Equator
Tropical continental (cT) originates over Sahara Desert, north of ITCZ
It brings long periods of hot and dry monotonous weather
Air mass is stable so there are warm winds with little cloud
Tropical maritime (mT) originates over Atlantic Ocean, south of ITCZ
It brings lots of moisture as well as rainy and warm air
Air mass is unstable so there are heavy showers of rain for long periods of time
