Chapter: Atmosphere

Table of Contents

Section 3: Air Movement

Section 1: Earth's Atmosphere

Section 2: Energy Transfer in the

Atmosphere

Chapter: Atmosphere

Table of Contents

Section 2: Energy Transfer in the

Atmosphere

*What is Heat?

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

**This transfer of heat occurs until THERMAL

EQUILIBRIUM is reached.

Thermal equilibrium is reached when there

is no more temperature difference between

the bodies that are exchanging heat

Heat = Thermal Energy

• It depends on the vibration of the atoms

that make up the object.

• The more vibration – the higher the

temperature

Energy from the Sun

• Earth's energy comes mostly from the Sun.

• What happens with this energy once it arrives on Earth?

2

What happens with the energy from the Sun?

35% is reflected

back into space by

atmosphere and

earth's surface

65% absorbed

by the

atmosphere,

the land and

the water.

How heat is transferred within

Earth’s atmosphere

• Once it is absorbed, this energy will be

transferred by different processes:

radiation, conduction, and convection.

• Radiation: is energy that is transferred

in the form of waves.

• Conduction: is the transfer of energy

by contact

• molecules collide and transfer heat

• Conduction Lab: What happened?

• the water in the two containers had

different temperatures

• The waters were not in contact

• the aluminum bar was in contact with

both waters and transferred the heat

from the warmer one to the colder one.

Convection: is the transfer of heat by the flow of

material (more common in liquids and gases)

The flow generates Convection Currents

• Demo – Convection: what happened?

• the warm water (red) moved up because it

is less dense.

• it cooled down, became denser

• moved to the bottom of the container,

creating convection currents.

• The convection currents mixed warm water

with cold water.

• All the water turned red and reached the

same temperature

*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

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

***Importance of the heat from

the Sun

1)The energy from the Sun allows life to

exist. – warms us up, allows

photosynthesis to happen for the

production of food and oxygen.

2)**The heat from the Sun is the driving

force of weather and climate.

By warming up the water, the land and the

atmosphere, it creates the movement of

air and water.

Local weather and climate depend on

the movement of air and water around the

Earth and the atmosphere

**Movement of air – winds

**Movement of water – water cycle

**Water Cycle – is the constant movement

of water through the atmosphere,

hydrosphere and land, due to the Sun’s

energy.

The water cycle involves the processes of

evaporation, condensation, precipitation

and the flow of water on and under the

Earth’s surface.

**Water Cycle, Weather and Climate

• The processes of evaporation,

condensation and precipitation involved

in the water cycle, allow heat and

moisture to move from one area to

another

• These processes , plus the movement of

air, are responsible for weather and

climate on Earth.

Earth’s Atmosphere is Unique

*Earth’s atmosphere is unique

*It is the atmosphere that guarantees a balance between energy absorbed and reflected, creating the ideal conditions for life to exist.

• Why doesn’t life exist on Mars or Venus?

• Read the book , page 102

2

The atmosphere in Mars is very thin.

There are not enough gases to trap the Sun’s heat.

Mars is too cold and does not have enough atmosphere to support life.

There is some water in form of ice.

Why there is no life in Mars?

Venus

Venus is very hot due to the gases in its atmosphere.

Carbon dioxide: 96 percent

Nitrogen: 3.5 percent

Venus’s dense atmosphere trap heat coming from the Sun - greenhouse effect

Venus2

• Living things would burn instantly if they were placed on Venus’s surface.

• Also the air pressure is extremely high because of the high density of the gases in the Venus atmosphere.

• We could not survive this atmospheric pressure.