G7 - Chapter 12 Final Revision

G7 - Chapter 12 Final Revision

12.1 Atmosphere

12.2 Weather

12.3 Severe Weather

MOE book page 490 >> log into ALEF 147/148/149

I can:

•  Discuss the components of the atmosphere

• Compare between the different layers of the atmosphere

• Interpret the movements of air

• Investigates cloud formation. and its three main types

[1]Atmosphere

The atmosphere is the gas mixture that surrounds Earth.

Components of Atmosphere

Air is mostly made up of nitrogen and oxygen.

Structure of Earth’s Atmosphere

The characteristics of Earth’s atmosphere change as altitude changes.

[2] What is wind?

Air moves in the troposphere because of differences in air pressure. This air movement is called wind.

The process of moving air called convection.

• The Sun warms Earth's surface, including the land and sea.

• The heat released by Earth warms the air in the lower part of the troposphere.

• Warm air is less dense than cool air. So, it rises high in the troposphere.

• As the warm air rises, moving away from Earth's surface, it cools.

• Cool air is denser than warm air. So, cool air sinks back to Earth's surface.

• The cooled air warms and rises again.

Types of winds

Local Winds and Global Winds

Multiple Choice

What is the Cause of Local Winds

• air flows from a low-pressure area to a high-pressure area

• air flows from a high-pressure area to a low-pressure area

• due to Earth’s rotation and the shape of Earth

Global winds

Westerlies and trade

Multiple Choice

Westerlies blow from west to east. However, Earth rotation turns them away from the Equator.

Multiple Choice

Trade blow from west to east. However, Earth rotation turns them away from the Equator.

[3] Clouds

Clouds are a collection of water droplets or ice crystals floating within the troposphere.

Cloud Formation

• Evaporation: Sunlight heats the water. Water change from a liquid to a gas.

• Water evaporates from various surfaces ex: oceans, lakes, rivers or organisms.

• Condensation As the water vapor rises, it changes into liquid

• The liquid water condenses around dust or pollen grains, forming water droplets which become a cloud.

Types of clouds

Main 3 types:

Cumulus - Stratus - Cirrus

I can

• Describe the weather and its various elements

• Explore the changes in the weather

• Distinguish between the different types of air fronts

[1] Weather 

Weather is the condition of the atmosphere at one time in one place. It occurs because of the moving air in the troposphere.

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[2] Air Masses and Weather Changes

air mass is a large volume of air that has uniform temperature, pressure and humidity.

Pressure System

The movement of air within the troposphere regularly changes air pressure. Any area can be high pressure or low pressure depending on the location of the air.

Multiple Choice

High-pressure systems are responsible for clear skies=no cloud.

Multiple Select

Low-pressure systems are responsible for ..................

• precipitation

• clear skies

• storms

• No cloud

[3] Front 

front is a boundary between two different air masses.

It is a line where two air masses meet.

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Multiple Select

which of the following is correct about warm front?

• temperature increases

• humidity increases

• thunderstorm might occur

• humidity decreases

• temperature decreases

Multiple Select

What happen where the cold and warm fronts meet.

• Sky starts to be clear

• Cumulus clouds formed

• sometimes thunderstorms formed

Multiple Choice

Which of the following tell you that there will be long periods of rain

I can

• Discuss how thunderstorms are formed

• Describe tornadoes and their scale

• Explain the formation of hurricanes and the scale of their damage

• Investigate the impacts of hurricanes

Multiple Select

Which of the following is an example of severe weather.

[1] Thunderstorm 

= severe weather event that includes thunder+lightning+strong wind+rain.

Open Ended

How is cumulus cloud related to thunderstorm formation?

Refer to ALEF 152

Formation of Thunderstorms

• Warm, moist air rises, cools and condenses into a cumulus cloud. As the warm air keeps rising, the cloud grows bigger.

• cumulonimbus cloud [grown cumulus] is formed.

• Rain starts to fall when water droplets become too heavy to stay in the cloud.

• The upward and downward flow of air within the cloud creates lightning and thunder.

• thunder+lightning+strong wind+rain

[2] Tornadoes

A tornado is a fast spinning column of air that reaches down to the ground from a cloud.

They are sometimes called twisters.

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Multiple Choice

Scale used to classify tornadoes. choose the correct answer

• Saffir–Simpson hurricane wind scale

  (SSHWS).

• Enhanced Fujita Scale

  (EF-Scale)

• Mohs' scale

Multiple Choice

If Winds from 178 km/h to 322 km/h [EF-2 On the scae] , the tornado would be................

• light damage

• Weak tornadoes that only cause damage but not destruction.

• very strong and highly destructive tornadoes.

• Strong and destructive

Wrap it

log into ALEF 154, Complete the opposite organizer and upload it to LMS Course for sharing

[3] Hurricanes

intense tropical storm with wind speeds of 119 km/h or more.

Multiple Select

Which of the following is correct about Hurricanes

• Rated on Saffir–Simpson hurricane wind scale (SSHWS)

• average diameter of 480 km

• formed from cirrus clouds

• produces lightning

Multiple Choice

In the eye wall:

rains are most intense and winds are strong

Multiple Choice

Describe Eye of hurricane

• skies are clear and winds are light

• rains are most intense

• winds are strong

hurricane formation

• Hurricane begins gently as a thunderstorm

• due to warm ocean, hurricane gains energy and become tropical storm

• humid air adds water to the formed tropical storm

Multiple Choice

Hurricanes produce powerful winds that could be so powerful and destroy anything in their way.

Which effect is shown in the opposite GIF

Hint: Increasing sea level

• Storm surges

• lightning

• heavy rain

Take a look at the Saffir–Simpson hurricane wind scale (SSHWS) in ALEF 155 TO ANSWER the following questions

ALEF 155 > 8^th slide [last one]

Multiple Choice

At which speed, there would be erosion of beach areas?

• 119-153 km/h

• 154-177 km/h

• 187-209 km/h

• 210-249 km/h

• > 249 km/h

Multiple Choice

At which speed, there are some trees are snapped or unrooted

• 119-153 km/h

• 154-177 km/h

• 187-209 km/h

• 210-249 km/h

• > 249 km/h