Aim: What’s the difference between weather and climate?

Write down notes using Cornell Method This will be checked as part of today’s Class work.

What is climate? Climate is all the characteristics of the weather in an area over a long period of time.

The climate of any region on the Earth is determined by two basic factors: temperature and precipitation.

Factors That Affect Temperature Latitude, elevation, and the presence of ocean currents are three natural factors that affect the temperature at a particular location.

What is latitude? Latitude is a measure of the distance north and south of the equator

Areas close to the equator, or 0 degrees latitude, receive the direct rays of the sun. These direct rays provide the most radiant energy. So areas near the equator have a warm climate. Polar regions have a cold climate.

What is elevation? Elevation, or altitude, is distance above sea level.

As elevation increases, the air becomes less dense As elevation increases, the air becomes less dense. This means that there are fewer gas molecules in the air and they are spread farther apart. So what’s the relationship between elevation and temperature?

Less-dense air cannot hold as much heat as denser air Less-dense air cannot hold as much heat as denser air. So as elevation increases, the temperature decreases. The temperature at the top of a mountain is lower than the temperature at sea level.

Mount Kilimanjaro in Africa

What is an ocean current? an ocean current is a "river" of water that flows in a definite path in the ocean. Some ocean currents are warm water currents. Other ocean currents are cold water currents.

The surface temperature of water affects the temperature of the air above it. Warm water warms the air and cold water cools the air. So what’s the relationship between the ocean current passing near a land area and temperature over that land?

Land areas near warm water currents have warm temperatures Land areas near warm water currents have warm temperatures. Land areas near cold water currents have cool temperatures. ESRT

Ireland is at the same latitude as many parts of central Canada Ireland is at the same latitude as many parts of central Canada. Why do you think Ireland has a warmer climate?

Ocean currents traveling away from the equator are warm water currents Ocean currents traveling away from the equator are warm water currents. Land areas located near these currents have warm temperatures.

The Gulf Stream is an ocean current that carries warm water from the southern tip of Florida along the eastern coast of the United States. How do you think the warm waters of the Gulf Stream affect the climate of the eastern United States?

Ocean currents traveling toward the equator are cold water currents. Areas located near these currents have cool temperatures. Off the western coast of the United States, the California Current flows toward the equator. What kind of temperatures would you expect along the coast in this area?

Review What’s the difference between weather and climate? What are the factors that affect climate? What are the factors that affect temperature?

What are the factors that affect precipitation? Climate What are the factors that affect precipitation?

Factors That Affect Precipitation The two natural factors that affect the amount of precipitation at a particular location are prevailing winds and mountain ranges.

What are prevailing winds? A wind that blows more often from one direction than from any other direction is called a prevailing wind. The amount of moisture carried by a prevailing wind affects the amount of precipitation a region receives.

Which can hold more moisture, warm air or cold air? Warm air can hold more moisture than cold air. As warm air rises, it cools and cannot hold as much moisture. The moisture the air can no longer hold falls to the Earth as some form of precipitation. Thus winds formed by rising warm air tend to bring precipitation. As cold air sinks, it becomes warmer and can hold more moisture. So winds formed by sinking cold air tend to bring little precipitation.

The direction from which a prevailing wind blows also affects the amount of moisture it carries. Some prevailing winds blow from the land to the water (a land breeze). Others blow from the water to the land (a sea breeze). Which kind of prevailing wind do you think carries more moisture?

Remember that moisture gets into the air as a result of the evaporation of water from the Earth's surface.

How do mountain ranges affect precipitation? The amount of precipitation at a particular location is also affected by mountain ranges.

A mountain range acts as a barrier to prevailing winds; mountains cause air to rise. As the air rises, it cools. Remember that cold air cannot hold as much moisture as warm air. So the moisture in the rising air falls to the Earth. as precipitation.

As a result, the windward side of a mountain, or the side facing toward the wind, receives a great deal of precipitation. The region on the windward side of a mountain has a wet climate.

There is a rainy climate on the windward slopes of a mountain range because moist air rises, cool, and forms rain clouds. Dry air moving down the leeward slopes results in a desert climate

The area on the leeward side of a mountain is called a rain shadow. What kind of climate does this area have?

Class work What’s the difference between weather and climate? What are the factors that affect temperature? Explain each. What are the factors that affect precipitation? Explain each. To be checked in your notebooks Answer Review questions no. 29- 40 pages 148-149