ClimateClimate

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

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

What is climate?What is climate?

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

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

Factors That Affect Temperature Factors That Affect Temperature

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

What is latitude?What is latitude?

Latitude is a measure of the distance north Latitude is a measure of the distance north and south of the equator and south of the equator

Areas close to the equator, or 0 degrees Areas close to the equator, or 0 degrees latitude, receive the direct rays of the sun. latitude, receive the direct rays of the sun.

These direct rays provide the most radiant These direct rays provide the most radiant energy. energy.

So areas near the equator have a warm So areas near the equator have a warm climate. climate.

Polar regions have a cold climate. Polar regions have a cold climate.

What is elevation?What is elevation?

Elevation, or altitude, is distance above Elevation, or altitude, is distance above sea level. sea level.

As elevation increases, the air becomes As elevation increases, the air becomes less dense. This means that there are less dense. This means that there are fewer gas molecules in the air and they fewer gas molecules in the air and they are spread farther apart. are spread farther apart.

So what’s the relationship between So what’s the relationship between elevation and temperature?elevation and temperature?

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

Mount Kilimanjaro in AfricaMount Kilimanjaro in Africa

What is an ocean current?What is an ocean current?

an ocean current is a "river" of water that an ocean current is a "river" of water that flows in a definite path in the ocean. flows in a definite path in the ocean.

Some ocean currents are warm water Some ocean currents are warm water currents. Other ocean currents are cold currents. Other ocean currents are cold water currents.water currents.

The surface temperature of water affects The surface temperature of water affects the temperature of the air above it. Warm the temperature of the air above it. Warm water warms the air and cold water cools water warms the air and cold water cools the air. the air.

So what’s the relationship between the So what’s the relationship between the ocean current passing near a land area ocean current passing near a land area and temperature over that land?and temperature over that land?

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

ESRTESRT

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

warmer climate?warmer climate?

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

The Gulf Stream is an ocean current that The Gulf Stream is an ocean current that carries warm water from the southern tip carries warm water from the southern tip of Florida along the eastern coast of the of Florida along the eastern coast of the United States.United States.

How do you think the warm waters of the How do you think the warm waters of the Gulf Stream affect the climate of the Gulf Stream affect the climate of the eastern United States? eastern United States?

Ocean currents traveling toward the Ocean currents traveling toward the equator are cold water currents. equator are cold water currents.

Areas located near these currents have Areas located near these currents have cool temperatures. cool temperatures.

Off the western coast of the United States, Off the western coast of the United States, the California Current flows toward the the California Current flows toward the equator. equator.

What kind of temperatures would you What kind of temperatures would you expect along the coast in this area?expect along the coast in this area?

ReviewReview

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

What are the factors that affect climate?What are the factors that affect climate? What are the factors that affect What are the factors that affect

temperature?temperature?

ClimateClimate

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

Factors That Affect PrecipitationFactors That Affect Precipitation

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

What are prevailing winds?What are prevailing winds?

A wind that blows more often from one A wind that blows more often from one direction than from any other direction is direction than from any other direction is called a prevailing wind. called a prevailing wind.

The amount of moisture carried by a The amount of moisture carried by a prevailing wind affects the amount of prevailing wind affects the amount of precipitation a region receives. precipitation a region receives.

Which can hold more moisture, Which can hold more moisture, warm air or cold air?warm air or cold air?

Warm air can hold more moisture than cold air. Warm air can hold more moisture than cold air. As warm air rises, it cools and cannot hold as As warm air rises, it cools and cannot hold as much moisture. much moisture.

The moisture the air can no longer hold falls to The moisture the air can no longer hold falls to the Earth as some form of precipitation. Thus the Earth as some form of precipitation. Thus winds formed by rising warm air tend to bring winds formed by rising warm air tend to bring precipitation. precipitation.

As cold air sinks, it becomes warmer and can As cold air sinks, it becomes warmer and can hold more moisture. So winds formed by sinking hold more moisture. So winds formed by sinking cold air tend to bring little precipitation.cold air tend to bring little precipitation.

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

Which kind of prevailing wind do you think Which kind of prevailing wind do you think carries more moisture? carries more moisture?

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

How do mountain ranges affect How do mountain ranges affect precipitation?precipitation?

The amount of precipitation at a particular The amount of precipitation at a particular location is also affected by mountain location is also affected by mountain ranges. ranges.

A mountain range acts as a barrier to A mountain range acts as a barrier to prevailing winds; mountains cause air to prevailing winds; mountains cause air to rise. rise.

As the air rises, it cools. As the air rises, it cools. Remember that cold air cannot hold as Remember that cold air cannot hold as

much moisture as warm air. much moisture as warm air. So the moisture in the rising air falls to the So the moisture in the rising air falls to the

Earth. as precipitation. Earth. as precipitation.

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

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

The area on the leeward side of a The area on the leeward side of a mountain is called a rain shadow. mountain is called a rain shadow.

What kind of climate does this area have? What kind of climate does this area have?

Class workClass work What’s the difference between weather What’s the difference between weather

and climate?and climate? What are the factors that affect What are the factors that affect

temperature? temperature? Explain eachExplain each.. What are the factors that affect What are the factors that affect

precipitation? precipitation? Explain eachExplain each.. To be checked in your notebooksTo be checked in your notebooks Answer Review questions no. 29- 40 Answer Review questions no. 29- 40

pages 148-149pages 148-149