Winds, Cyclones, and Anticyclones

Station 1

WINDS

• Winds are caused by a difference in air pressure due to unequal heating of the atmosphere

• Heating the air, decreases pressure (warm air rises creating a low pressure)

• Cool air rushes into replace the warm air (cooler dense air, produces high pressure)

• As air goes from high to low pressure, winds form.

Two Types of Winds

1. Local Windsa. cover short distancesb. Blow from any directionc. 2 Types of Local Winds• Sea Breezes- from sea to land• Land Breezes – from land to sea

Two Types of Winds

2. Global Winds a. Don’t travel North and South because of the

Earth rotating on its axis.b. 4 Types of Global Winds

i. Doldrumsii. Trade Windsiii. Prevailing Windsiv. Polar Easterlies

2 primary methods for air mass movement

a. Prevailing Westerlies: Pushes air masses from west to east.

b. Jet streams: Pushes fast moving air masses from west to east.

CYCLONES

a. Formed around centers of low pressure.b. Caused as the boundary between fronts become

distorted by surface features; mountains or strong winds.

c. Represented on weather maps by an L.d. Warm air rises and spins counterclockwise around

the center.e. Storms and precipitation are associated with areas of

low pressure as the warm air rises & condenses to form clouds & precipitation.

ANTICYCLONES

a. Formed around centers of high pressure.

b. Represented on weather maps by an H.c. Cold air sinks and spins clockwise around the

center.d. Dry weather and clear skies are associated with

areas of high pressure as the cooler air falls & becomes warmer causing a drop in relative