Ch. 3 Weather and Climate

Big Idea: How the Sun affect the Earth’s atmosphere and how solar energy is distributed abound the globe.

http://www.youtube.com/watch?v=lrPS2HiYVp8

Section 1 Factors Affecting ClimateI. The Sun and Latitude

A. Weather is the condition of the atmosphere at a given time & place

B. Climate- weather conditions in a region over a long period of time

C. The closer you are to the tropics and the sun’s direct rays, the warmer you are…duh

D. Temperature-measurement of heat

E. Atmosphere reflects half of sun’s energy and absorbs the other half which heats up the earth

F. Greenhouse Effect=Global warming-Earth allows sun’s heat in, traps it and slowly allows it to release into space-CO2 absorbs heat.

H. Some say man is responsible while others say it’s a natural cycle

Do you know?

• How does the Earth’s Atmosphere help keep the planet Warm?

• Green house effect- slowing the loss of heat into space

Random Fact • Venus and global warming

– Venus is 96 % CO2 and because of this it is 890 F

• The Little Ice age 1500’s -1800’s

II. Atmospheric Pressure

A. Pressure of air

B. Higher you go, less pressure

C. As air heats up, it expands, becomes less dense and rises (low pressure system)

D. Air rises, cools and forms water vapor = clouds

E. Centers of low pressure systems are called cyclones… sometimes a slight breeze while other times a powerful storm

F. High pressure systems are created from cold air sinking towards the Earth = stable, clear and dry weather

Do you Know

• What kind of weather is usually associated with an area of Low pressure?

• Unstable weather, anything from a slight breeze to bad storms

III. Global Wind Belts A. Wind flows from high pressure areas to low

pressure areas B. Think of air leaving a tire C. Prevailing winds- blow from the same

direction all the time…NE and SE trade winds, westerlies, easterlies

D. Doldrums-along Equator, calm…little wind

Tropic of Cancer

Equator

Tropic of Capricorn

E. Front-two air masses of widely different temps or moisture levels meet

F. Usually results in precipitation

G. Prevailing winds up in atmosphere make up the jet stream… wind speed can reach 300 miles per hour

H. Jet streams move heat and major weather patterns

Do you Know?

• How is wind directly related to the differences of air pressure?

• Wind flows from high areas of high pressure to low pressure areas

IV. Ocean and Currents

A. Water heats and cools more slowly than land

B. Locations near large bodies of water have more consistent temps then inland locations

C. Earth’s wind, rotation and temperatures create currents (great rivers of sea water)

D. Move clockwise in NH and counter in SH

E. Currents help balance water temperatures in the oceans by moving it all around.

Do you know?

• What are the main forces that create ocean currents?

• Wind, earth’s rotation, varying ocean temperatures