Climate and the structure of the Atmosphere Flashcards
What drives weather and climate on Earth’s surface?
The movement of energy and mass through space, driven by imbalances in Earth’s energy budget.
Why do the poles receive less solar energy than the equator?
Due to Earth’s curvature, sunlight is spread over a larger area and takes a longer path through the atmosphere at higher latitudes.
Net gain of energy.
Equator & tropic
Net loss of energy.
Poles
How does humidity affect air density?
Humid air is lighter than dry air because H₂O molecules replace heavier N₂ and O₂ molecules.
What happens to air pressure as altitude increases?
Air pressure decreases, causing air to expand and cool (adiabatic cooling).
The rate at which air cools as it rises due to expansion.
adiabatic lapse rate
~10°C/km (unsaturated air).
Dry adiabatic lapse rate
Slower due to condensation releasing latent heat.
Moist adiabatic lapse rate
Stored energy in water vapor that is released during condensation, fueling storms.
Latent heat
What are the three main atmospheric circulation cells?
Hadley Cell, Ferrel Cell , Polar Cell
Warm air rises at ITCZ, moves poleward, then sinks at subtropical highs.
Hadley Cell (0°-30°)
Moves opposite Hadley and Polar Cells, driven by their motion.
Ferrel Cell (30°-60°)
Cold air sinks at the poles, moves toward the equator, then rises at the Polar Front.
Polar Cell (60°-90°)
A low-pressure zone near the equator where warm, humid air rises, leading to heavy rainfall and tropical rainforests.
the Intertropical Convergence Zone (ITCZ)
Why are deserts located around 30° latitude?
Air sinks in the subtropical high-pressure zones.
This air is dry and compresses, leading to low humidity and arid conditions.
What happens at the Polar Front?
Warm, moist air from the Ferrel Cell meets cold, dry air from the Polar Cell, leading to storm formation.
The deflection of moving air due to Earth’s rotation.
Coriolis Effect
Air deflects right.
Northern Hemisphere
Air deflects left.
Southern Hemisphere
What are the major wind belts on Earth?
Trade winds, Westerlies, Polar Easterlies
Blow from east to west (0°-30°)
Trade Winds
Blow from west to east (30°-60°
Westerlies
Blow from east to west. (60°-90°)
Polar Easterlies
How do extratropical cyclones form?
Warm, moist air from the Ferrel Cell meets cold, dry air from the Polar Cell.
Warm air rises over cold air, condenses, and releases latent heat.
This fuels storm growth and reinforces low pressure.
A fast-moving ribbon of air in the upper atmosphere that follows the Polar Front, guiding storms and influencing weather.
Jet Stream
How do hurricanes (tropical cyclones) form?
Warm ocean water evaporates, creating humid air.
Rising air condenses, releasing latent heat.
The Coriolis Effect causes rotation, forming a spinning storm.
What type of climate is found at the ITCZ?
Warm, wet, and rainy (Tropical Rainforests).
Why are the Horse Latitudes (30°) dry?
Sinking air compresses and warms, leading to low humidity and deserts.
It steers storms and influences seasonal weather patterns
role of the Polar Jet Stream
What drives global climate and weather?
Uneven solar heating, atmospheric circulation, and ocean currents.
