Chapter: Atmosphere

Table of Contents

Section 3: Air Movement

Section 1: Earth's Atmosphere

Section 2: Energy Transfer in the

Atmosphere

Chapter 4: Atmosphere

Table of Contents

Section 1: Earth's Atmosphere

What you will learn and why it’s

important page 90

The importance of the

atmosphere

• What is atmosphere?

• It is a thin layer of gas that forms a

protective layer around the planet

• What is the importance of the

atmosphere ?

1- contains the oxygen that we need to

survive

2- it is a radiation shield that protects us

3- It keeps us warm- absorbs the heat and

prevents it from radiating out into space

Other importances

4- protects us from objects falling from

space – these pieces of rock burn out due

to the friction of the air.

5- Carbon Dioxide from the atmosphere

allows plants to do photosynthesis

6- sound travels through air, allowing us to

even listen to one another

The Makeup of the Atmosphere over time

• Earth's atmosphere is a mixture of gases, solids, and liquids that surrounds the planet.

1

Earth’s Atmosphere

atmosphere was rich in Nitrogen and Carbon Dioxide

the amount of oxygen increased mostly due to the photosynthesis from algae life was mostly under water

more oxygen was formed Ozone layer appeared allowing life out of the water

the atmosphere kept on changing and is still changing due to man intervention

1

Ozone protects Earth from sun’s harmful rays

Layers of the atmosphere

(book pages 92 and 93)

• What is air made of ?????

Atoms Matter Mass Weight

Does air have weight?

What do you feel when you have something heavy

on your lap?

Pressure

Atmospheric Pressure

• Atmospheric gases have mass.

1

Earth’s Atmosphere

• We have lots of gases on top of us, lot of atoms and molecules

• these gases pressure down on the air below and this is Atmospheric Pressure

**Definition

Atmospheric Pressure

1

Earth’s Atmosphere

Pressure caused by the weight of the atmosphere.

At sea level you have maximum atmospheric

pressure but it reduces with increasing altitude

because the molecules of the gases are further

apart.

Composition of the Atmosphere1

Earth’s Atmosphere

Also found:

Water

Droplets

Sand

Salt

Pollen

• the composition of the atmosphere is changing in small but important ways.

1

Earth’s Atmosphere

• The constant burning of fossil fuels is increasing the levels of certain gases in the atmosphere

The increased

amount of

greenhouse

gases in the

atmosphere

accentuates the

greenhouse

effect,

affecting the

climate in certain

areas

Global Warming

• Throughout history, Earth has warmed

and cooled several times.

• Nowadays, the climatic warming is

occurring much faster then in the past

Global Warming

• Global warming is the unusually rapid

increase in Earth’s average surface

temperature over the past century.

Causes of Global Warming(1)

• Natural causes:

Variations in Sun's energy

Subtle shifts in the Sun’s orbit

Fluctuation in ocean currents

Volcanic eruptions

Causes of Global Warming (2)

• Global warming is primarily happening

due to the greenhouse gases released

by people burning fossil fuels.

• Methane, water vapor, carbon dioxide,

fluorinated gases such as CFC

(chlorofluorocarbons) – are called

greenhouse gases and increase the

greenhouse effect

Effects of Global warming

• Not only the increase in Earth

temperature, but also:

• Modification of rainfall patterns

• Amplification of coastal erosion

• Melting of ice caps and glaciers

All these will affect the living organisms in

the planet

You tube video

• Global Warming Facts - NASA Global

Warming

• https://www.youtube.com/watch?v=ROZ

JmX73FF4

The Ozone Layer

• Located in the stratosphere

1

Earth’s Atmosphere

• Ozone is made of oxygen.

Your life depends on Ozone1

Earth’s Atmosphere

• The ozone layer shields you from the Sun's harmful energy.

• Ozone absorbs most of the ultraviolet radiation that enters the atmosphere.

CFCs

• Evidence exists that some air pollutants, such as CFCs, are destroying the ozone layer.

1

Earth’s Atmosphere

• chlorofluorocarbons (CFCs) - chemical compounds used in some refrigerators, air conditioners, and aerosol sprays, and in the production of some foam packaging.

Chlorofluorocarbon molecules destroy ozone and the products do not absorb UV rays from the Sun

1

The Ozone Hole

• The destruction of ozone molecules by CFCs seems to cause a seasonal reduction in ozone over Antarctica called the ozone hole.

• The levels of Ozone over Antarctica follows an yearly pattern and increases and decreses during the year

1

Earth’s Atmosphere

Oct. 2014 Ozone hole Nasa

update

The 2014 Ozone hole is comparable to

the size of the holes in 2010, 2012, 2013.

It is a little bigger than 2013.

It did not reach the biggest sizes that were

observed during the period of 1998- 2006.

Oct. 2014 Ozone hole Nasa

update

One factor could be influencing the

higher levels of ozone in Antarctica:

- Decline of CFC in the atmosphere. The

level of CFC declined 9% since 2000

Chapter: Atmosphere

Table of Contents

Section 2: Energy Transfer in the

Atmosphere

Energy from the Sun

• The Sun provides most of Earth's energy.

• This energy supports life ( sun’s energy is needed for photosynthesis)

• The energy that the Earth receives from the sun can be absorbed or reflected.

2

Energy Transfer in the Atmosphere

Energy from the Sun2

35% is reflected

back into space

65% absorbed

by

the atmosphere,

the land and

the water.

What is Heat?

• Heat is energy that flows from an object with a higher temperature to an object with a lower temperature.

2

The sun’s energy reaches the Earth can be absorbed or reflected back into space.

Once it is absorbed, heat can be transferred by radiation, conduction, and convection.

1) Radiation

• is energy that is transferred in the form of rays or waves.

2

• Radiant energy from the sun, warms the Earth.

2) Conduction

• is the transfer of energy that occurs when molecules bump into one another.

2

Energy Transfer in the Atmosphere

• It happens when objects are in contact.

• Ex: when you touch something hot or when cold air is warmed up by passing through warm land

3) Convection:

is the transfer of heat by the flow of material.

It can happen in the atmosphere, in your house, when you warm up water in a pan.

2

Convection: circulates heat throughout the atmosphere.

2

Convection in a liquid2

Convection in gases2

Convection

• This movement of air or liquid form what we call convection currents.

2

Energy Transfer in the Atmosphere

• What is Hydrosphere?

2

• Hydrosphere is a term that describes all the water on Earth’s surface.

2

• The constant movement of water through the

atmosphere and the hydrosphere will affect

climate.

This constant movement is called Water Cycle

On your notebooks, describe the water cycle2

*Climate x Weather

*Weather – is the state of the atmosphere

at a specific time and place. Ex: today is

raining

*Climate – average weather pattern in an

area over a long period of time. Ex:

Washington is humid during summer

*Both are determined by: precipitation and

temperature

Water Cycle and Climate

• The climate of a certain area depends

on its average temperature and

precipitation.

• Temperature and precipitation are

affected by the water cycle.

• So, the water cycle affects climate.

Chapter: Atmosphere

Table of Contents

Section 3: Air Movement

When substances

are mixed:

less dense will float

on the denser one

different densities

cause convections

EX: air and water

Density:

Air Density

• What happens to the molecules of a

substance when this substance is

warmed up? Does the density change?

The molecules or particles will expand

and the substance will become less dense

Density of gases depends on temperature

higher temp. air have lower density -

air rises

Blue cube – higher density - more molecules

Pink cube – lower density – less molecules

**The is a relationship in between

Density and Atmospheric Pressure

• Warmer, lower density air - will rise

and the molecules are further apart from

each other ( less dense)

• Where the air is less dense, the

atmospheric pressure is lower

Heated Air

• Areas of Earth receive different amounts of radiation from the Sun because Earth is curved.

3

• some areas are warmer than others.

• Latitudes closer to the Equator are warmer

Longitude and Latitude

How are Winds formed?3

1)The heated air at

the equator is less

dense.

2)Moves up in the

atmosphere

3) It is replaced by

denser, colder air

from

the poles.

*Forming Wind3

*The air movement creates areas with different pressures in the atmosphere which creates all the winds that circulate around the globe.

*Wind is the movement of air from:

an area of higher pressure ( colder air and more dense) to an area of lower pressure ( warmer air and less dense).

How air moves

What causes wind?

1)The movement of colder air and warm

air on the Earth surface

2) The Coriolis effect

*Coriolis Effect – is a phenomenon that

causes fluids such as air and water to

curve as they travel across and above the

Earth’s surface.

The rotation of the Earth is what causes

the deflection of these fluids.

*Coriolis Effect and Air Movement

Coriolis Effect and Air Movement

****This deflection, caused by the

Coriolis effect, impacts the way winds

and storms move around the Earth.

*Coriolis Effect and Air Movement

• winds and water are deflected to the

right in the Northern Hemisphere and to

the left in the Southern Hemisphere.

Coriolis Effect and Air Movement

Youtube video

• The Coriolis Effect ( 3:06)

• Why do storms spin in different

directions depending on their location—

and why do they spin in the first place?

pbs.org/nova/labs

• https://search.yahoo.com/search?p=you

+tube+coriolis+effect&ei=UTF-

8&fr=moz35

WINDS

Graphic organizer

• Two types: Global winds and Local

winds

• Global Winds – affect the weather

patterns for the entire planate

• Local Winds – affect local weather

What are the Doldrums ??

Trade winds from North

to South meet at the

Equator creating

doldrums. Area of low

atmospheric pressure

and low winds

(Sailors avoid it)

Doldrums and rain

• Areas of low pressure have :

warmer air that will rise

• Warmer air rise and meets with colder

temperatures

• Warm air will condense – form clouds –

if cloud is too heavy – rain

• USUALLY IN THE DOLDRUM AREA IT

RAINS EVERYDAY

Manaus

Local Winds: Sea and Land Breezes

3

• These breezes will blow in one direction during the day and to the opposite direction at night

Sea and Land Breezes3

• This will happen because of the differences in the temperatures of land and water.

• It takes more time for the water to cool and warm up compared to the land.

Sea and Land Breezes3

• This will happen because of the differences in the temperatures of land and water.

• It takes more time for the water to cool and warm up compared to the land.

***Low Pressure X Bad Weather

*In areas of low pressure, the warm air will

rise, reaching areas that are colder.

In colder areas this air will condense

forming clouds that might precipitate in the

form of rain

winds

*Global winds are winds that cover long

distances.

*trade winds- the air movements toward

the equator are called trade winds and

these winds blow almost continuously.

*The trade winds blow towards

the equator.

Trade winds coming from the south and

the north meet near the equator creating

an area of calm called the doldrums.

*In the doldrums, which is close to the

Equator, the warmer air rises, creating a

zone of low pressure, where it rains

almost every afternoon.

• *Prevailing Westerlies – are winds that

blow in the opposite direction of the

trade winds and are responsible for most

of the weather across North America

*Jet Streams - are winds that blow near

the top of the Troposphere ( layer of the

Atmosphere closer to the Earth)

These winds help move storms from one

area to another.

1) What is the definition of atmosphere and the

composition of the atmosphere

2) What are the different layers of the atmosphere

and in which layer do we leave?

3) What is Ionosphere?

4) What is the Ozone layer and is it important? In

which layer of the atmosphere is I located?

5) Explain the effect of CFCs in the Ozone Layer.

6) What are some of the causes of the hole in the

Ozone layer?

Review Chapter 4

7) What is Hydrosphere?

8) Explain the difference between the 3 ways in

which heat can be transferred in the atmosphere.

9) Explain the relationship among air temperature,

air density and low or high atmospheric pressure.

10) What are the two types of local winds ? Explain

the movement of the local winds during a period of

24 hours.

11) What happens to the atmospheric pressure

when you go up in altitude??? Why?

12) -What are doldrums and why does it rain

frequently in the doldrums area?

End of Chapter Summary File