Wind Flashcards
Wind
A moving mass of air whose path is parallel to the Earth’s surface
Air current
A moving mass of air traveling up and down relative to the surface of the Earth
How are winds and air currents caused?
By convection currents created from uneven heating of the atmosphere
Why are winds and air currents important?
They move air and water vapor from one place to another; carry away polluted air from cities; and help keep the contents of the atmosphere balanced
One liter of warm air contains ____ molecules than a liter of cool air. Air always moves from a ___ pressure to a ___ pressure region. Air molecules are closer together in ___ air than in ___ air.
Fewer High Low Cool Warm
Convection cell
Area where air is moving in a circular pattern due to its convection currents. Dense, cool air is falling, while less dense, warm air is rising
If the Earth did not rotate, in what pattern would the winds move?
Air would heat at the Equator and rise. It would then flow toward the North and South poles (high altitude winds) where it would cool and fall, flowing back toward the Equator (ground winds)
Coriolis Effect
Describes how the rotation of the Earth affects the pattern of the winds. Winds are deflected from their paths.
Ferrel’s Law
In the Northern Hemisphere, winds are deflected to the right of their original path. In the Southern Hemisphere, they are deflected to the left.
Name the three primary wind systems in the Earth’s atmosphere and give their locations.
Polar easterlies: in the polar regions
Prevailing westerlies: between the equator and the poles
Trade winds: at the equator
Air moving from the Equator to the poles starts to cool and sink at the ___. Winds blowing from there toward the Equator are called ____; and blowing toward the poles, ___. Cold air from the poles is called___
horse latitudes
trade winds
prevailing winds
polar easterlies
Define sea breeze. How is it created? When does it occur?
A cool wind coming from the ocean to land. It usually lasts most of the day. Cooler and denser air over ocean sinks and is replaced by warmer air from the land (a convection current)
Define land breeze. How is it created? When does it occur?
A breeze flowing from land to sea. At night the air over the land is cooler than air over the ocean. A convection current is created when the cooler land air sinks and is replaced by warmer sea air.
Define monsoon. Where do they take place?
Large-scale sea and land breezes that bring very heavy rains in the summer and dry weather in the winter to India. Certain areas of the US also experience this effect from Gulf Stream waters. Most non-desert equatorial locations experience monsoons.
Define valley breeze. How is it created? When does it occur?
A wind that blows from the valley up the mountainside. Caused when the Sun heats the mountain peaks faster than the valley. Occurs during the day.
