Climate

Weather vs. Climate Weather- State of the atmosphere at a given time and place; constantly changing Climate – The average weather condition of an area over a long period of time. Climate depends on how average weather conditions change throughout the year

Weather or Climate??? The average high temperature for the month of July in Chicago is 84oF. Cumulus clouds presently cover the entire sky. Snow is falling at a rate of 1 inch per hour. The summers here are warm and humid. At 3:00 p.m, winds were blowing from the NW at 10 mph. Total precipitation at O’Hare Airport for 2003 was inches, which is 4.25 inches below normal.

WHAT AFFECTS CLIMATE?

Latitude How far the region is from the equator, its latitude, helps control climate

How does latitude affect climate? As latitude ________, the average annual temperature _________. 0° Latitude 90° Temperature decreases increases

Unequal Earth Heating Regions near the equator receive more direct solar energy and thus have warmer temperatures Regions further away from the equator receive less direct solar energy and thus have colder temperatures

Elevation The height above Earth’s surface, or altitude, affects climate

How does elevation affect climate? As elevation _________, the average annual temperature __________. Elevation Temperature increases decreases

Mountains Mountains influence climate because they block prevailing winds

A rain shadow is an area of low rainfall on the downwind slope (leeward slope) of a mountain. The climate is dry and vegetation can be sparse. The windward side of the mountain is where rising air cools forming precipitation. There is an abundant amount of vegetation

Nearness to Large Bodies of Water Water absorbs and releases heat slower than land. Therefore, water helps to moderate the temperature of the land around it.  Maritime climates (by the ocean) are moderated (cooler summers, warmer winters) by the ocean Increases moisture content of the air. Precipitation is higher in maritime climates than in continental (inland) climates.

Ocean Currents The surface temperature of the water affects the temperature of the air above it. –When warm, they raise temperatures along the coast (especially in winter) and when cold, they lower temperatures (especially in summer)

Ocean Currents

Prevailing Winds Prevailing Winds- winds that blow mainly in one direction They affect the amount of precipitation a region receives When they move off large bodies of water onto land they moderate temperatures When they move from ocean areas onto land they bring moisture. Land to Land = Drier climates

CLASSIFYING CLIMATES

There are 5 climate types, based on regional temperature, precipitation, and vegetation

1.Polar Climates a)Tundra b)Ice Cap c)Highland Cold all year-round and have little precipitation.Cold all year-round and have little precipitation.

2. Dry Climates a)Semiarid b)Arid Has little precipitation, hot summers, and cooler winters.Has little precipitation, hot summers, and cooler winters.

3. Continental Climates a)Warm summer b)Cool summer c)Subarctic Has warm summers, cold winters, and moderate precipitation

4. Tropical Climates a)Tropical wet b)Tropical wet and dry Warm all year-round with high precipitation

5. Mild Climates a)Mediterranean b)Humid Subtropical c)Marine west coast Has high precipitation, warm summers, mild winters, and is humid

Microclimate: a localized climate that is different from the climate in the surrounding area Urban heat island- concrete absorbs heat raising the temperature of the area Forested microclimates- are often cooler and less windy than the surrounding countryside.

Global Warming - The rise in the Earth’s average surface temperature during the past 100 years.Global Warming Click on the hyperlink “Global Warming” above

Most scientists agree that most of this temperature change is the result of human activity that is increasing the greenhouse effect because of increasing levels of carbon dioxide in the atmosphere. These activities include:  The burning of fossil fuels  Deforestation- the large- scale cutting and burning of forests.  Increases C0 2 because there are fewer tress to use the gas.

Warmer temperatures cause: More evaporation in the oceans and change rain patterns worldwide glaciers & ice sheets to melt resulting in rising se levels Soil in the Arctic to melt