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?

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.

**Earth’s Atmosphere is Unique

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

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.

Convection: is the transfer of heat by the flow of

materials. The flow generates Convection

Currents

What are

convection

currents?

(more common in

liquids and gases)

• Why do convection currents happen?

Because of Density

Cold air is denser – molecules closer

Warm air is less dense – molecules are far

apart

It happens with air

It happens with air

It happens with water,

magma and fluids in general

Importance of the heat from

the Sun- handout

Two major reasons:

1)The energy from the Sun allows life to

exist

2)The heat from the Sun is the driving

force of weather and climate.

***Importance of the heat from

the Sun

1)The energy from the Sun allows life to

exist:

warms us up with radiation

Its light allows photosynthesis to happen

for the production of food (sugars) 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 (with radiation, conduction

and convection), it creates the movement

of air and water.

Movement of air = wind

Movement of water = water cycle

Remember:

• this happens also between land, water and

air

• Heat flows from where is warm to where

is cold

**The movement of air and water happens

due to the difference of temperature

from one area compared to others,

allowing heat and moisture to circulate

Local weather and climate depend on

the movement of air and water around the

land, the atmosphere and the water.

**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.

*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

• What is Hydrosphere?

• Book page 101

2

Describe the water cycle