Chapter 3.1

Pg. 41

Factors Affecting Climate

The Sun and Latitude

Weather is the conditions of the atmosphere at a given time and place. Weather conditions over a given time are the climate of that region.

The tilt of the Earth and the Sun make differences in weather and climate.

Continued

When the Sun’s energy hits Earth about half is reflected back. Earth’s surface absorbs the other half. The measurement of heat is called temperature.

Earth’s atmosphere traps heat energy in a process called the Greenhouse effect.

Continued Evidence shows that Earth has gotten warmer in

recent decades. Called Global Warming and most scientists believe it is caused by humans.

Burning coal, natural gas and oil adds carbon dioxide to the lower atmosphere. Carbon dioxide absorbs heat. Reducing production of carbon dioxide could help with stopping global warming.

Some people do not believe in Global Warming.

Atmospheric Pressure

Air Pressure The higher you go the less air you have pressing

down on you. Low pressure areas also occur when the air is

heated. Low pressure usually accompanies unstable

weather conditions.

Continued

Cold air is dense and sinks toward Earth’s surface. Creates a high pressure area. Air sinks it heats and dries and causes high pressure.

4 major air pressure zones. Equatorial low, subtropical highs, subpolar lows, ad the polar highs.

Global Wind Belts

Wind is the horizontal flow of air. Flows from high to low pressure.

Move heat and cold across earth. Winds that flow in the same direction most of the

time are prevailing winds. Doldrums are around the equator and there is not

much wind.

Oceans and Currents

Water heats and cools more slowly than land, land near the ocean do not have such great temperature ranges as areas in the interior of continents.

Great Rivers of seawater, called currents, are also important to climate.

Gulf Stream flows north along the U.S. east coast is a warm current.