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.