Chapter 12 - Meteorology

1.Meteorology Basics – A. Meteorology = The study of atmospheric facts, especially weather and changes.

B. Weather = the current state of the atmosphere (short-term)

C.Climate = changes in the weather of a particular area (long-term)

D. Weather changes redistribute the heat around the globe It is a way to balance the heat. Ocean currents also cause this.

Air Mass: large body of air with characteristics of the area where it formed Continental Tropical: warm and dry (desert southwest: Arizona) Maritime Tropical: warm and humid ( Southeast: Georgia) Continental Polar: cold and dry (Canada) Maritime Polar: cold and humid (North Pacific: Oregon) Arctic: VERY cold and dry (Greenland)

2. Pressure Centers A.High Pressure - Anticyclone (rotates clockwise) - Usually sunny skies

2. Pressure Centers A.High Pressure - Winds blow outward and downward

2. Pressure Centers B.Low Pressure - Cyclone (rotates counterclockwise) - Usually clouds and rain

2. Pressure Centers B.Low Pressure - Winds blow inward and upward

(the clockwise part is switched for the Southern Hemisphere)

Because Earth is rotating, winds are deflected to the right (Northern Hemisphere) from where they would normally travel, and to the left in the Southern Hemisphere. This is called the Coriolis effect.

3.Wind systems Since Earth is rotating, we get several different winds that move heat around the globe. A. Jet streams separate each wind system. B. A jet stream is a narrow, fast- blowing, stream of wind.

3.Wind systems

Trade Winds: 0-30° Prevailing Westerlies: 30-60° Polar Easterlies: 60-90°

4.Warm Front A. Warm air replaces cool air. B. Steady, light precipitation is produced.

4.Warm Front C. Illustration =

5. Cold Front A. Colder air replaces warm air. B. Violent weather occurs as the warm air is lifted.

5.Cold Front C. Illustration =

Stationary Front: a front that is barely moving due to slow winds Occluded Front: a cold front overtakes a warm front. This shoves the warm air upwards.