Weather and Climate
The Atmosphere
Ch. 17
November 29, 2010
Warm-Up 11/29 (10 min)
1.
2.
What is the study of the atmosphere
and the processes that produce weather
and climate called?
Why is it important to study the
atmosphere? (Give at least 5 reasons)
Objectives 11/29/10

I will be able to:
◦ Describe the composition of the atmosphere
◦ Describe the layers of the atmosphere
◦ Analyze the relationship between the Earth’s
tilt and the seasons
Weather and Climate… what’s the
difference?
Weather is always changing and refers to
the state of the atmosphere at a given
time and place
 Climate is based on the observations of
weather conditions over many years and
helps us describe a region


To understand weather and climate, we
first need to understand what our
atmosphere is made of
The Composition of the
Atmosphere
How old is the earth? _______
 Over this period of time the composition
of the atmosphere has changed
dramatically
 “Air” is not a single gas, it is a mixture of
gases

The Composition of the
Atmosphere
The most abundant gas in the atmosphere
is nitrogen
 The second most abundant is oxygen

◦ Together make up 99% of clean, dry air
Carbon dioxide is important for
absorbing energy in the atmosphere
 Water vapor is the source of all clouds
and precipitation and absorbs heat given
off by Earth

Composition of the Atmosphere
Ozone: a form of oxygen with three
oxygen atoms bonded together instead of
just two (that’s the O2 we breathe)
 Results from oxygen absorbing radiation
(energy) from the sun
 The ozone layer is crucial for life on Earth
because it absorbs potentially harmful
radiation
 The ozone layer allows life on Earth to
exist

The Composition of the
Atmosphere
We just finished talking about the oceans,
which contain water.
 Liquids are one type of fluid
 Gases are also fluids
 Most of the properties of our
atmosphere that influence weather,
climate, and life as we know it, come from
the fluid nature of the atmosphere
 Check it out!

The Structure of the Atmosphere
The atmosphere thins
very quickly as you
travel away from
Earth’s surface
 The atmosphere is
divided vertically into
4 layers based on
temperature

The Structure of the Atmosphere

Layers of the atmosphere
◦ The lowest = troposphere
 Temperature decreases as altitude increases
 Most important weather phenomena occur here
◦ 2nd = stratosphere
◦ 3rd = mesosphere
◦ Top = thermosphere
Diagram of the atmosphere
structure
Using page 480 as your
guide, diagram the
layers of the
atmosphere, including
the boundaries
between each layer
 For each layer, you
must write at least 2
facts about that layer

The Earth and Sun interactions


Nearly all of the energy for changing
weather and climate comes from the sun
Earth has 2 principle motions:
◦ Rotation: spinning around its axis
◦ Revolution: spinning around the sun


Earth’s axis is tilted about 23.5o
The Earth’s orbit is not completely circular
◦ These two facts, taken together explain why we
have seasons
Check it out
The Earth and Sun Interactions
The divisions between the seasons are called
equinoxes and solstices
 Solstices: mark the beginning of summer and
winter

◦ Summer solstice: the Northern Hemisphere is
“leaning” toward the sun at 23.5o
◦ Winter solstice: the Northern Hemisphere is
“leaning” away from the sun at 23.5o

Equinoxes: half-way between solstices, spring and
fall
◦ The Earth is tilted neither toward or away from the
sun
◦ The length of the day and night are equal
Check-ins
1.
2.
3.
4.
5.
6.
What is the most abundant gas in the
atmosphere? What is the second most abundant
gas in the atmosphere? Together, these two
comprise what percentage of atmospheric
gases?
What is the lowest layer of the atmosphere?
The layers of the atmosphere are divided based
upon what property?
In which layer of the atmosphere are most
important weather phenomena?
By how many degrees is the Earth tilted on its
axis?
Describe the autumnal and spring equinoxes.
Exit Ticket
1.
2.
3.
What is the most abundant gas in the
atmosphere?
What is the lowest layer of the
atmosphere?
Which of the following is true about
equinoxes?
a. They occur in June and December
b. The sun’s vertical rays strike at 23.50N or
23.50S
c. Days and nights are equal length everywhere
d. The length of daylight in the Arctic and
Antarctic circles is 24 hr
Warm-up 11/30/10
List the layers of the atmosphere from
lowest to the ground to highest?
 In which of these layers do most
important weather phenomena occur?
 REVIEW: On a map, we look at lines of
________ to measure north and south
of the equator
 Seasons are caused by ______________

Objectives
Describe the movement of heat due to
differences in temperature
 Analyze the absorbance and reflectance of
the sun’s energy on Earth
 Analyze temperature variations over land
and water

Heating of the Atmosphere
Heat vs. temperature
 Heat is the energy transferred from one
object to another due to differences in
temperatures.


Bottom line: heat is transferred between
objects because of differences in
temperature
Heating of the Atmosphere
The heating of the atmosphere comes from
solar energy
 The solar energy is transferred to Earth
through radiation
 When radiation hits an object, three things
happen

◦ 1. some radiant energy is absorbed
◦ 2. some radiant energy is transmitted through
substances like water and air
◦ 3. some radiant energy bounces off the object
without being absorbed or transmitted
Heating of the Atmosphere

Take a look at Figure 12 on
page 486 to answer the
following questions
1. How much of the Sun’s
energy that reaches Earth’s
atmosphere is reflected back
into space? (add together the
amount that is backscattered to space,
the amount reflected from clouds, and the
amount reflected by the land-sea surface)
2. How much of the Sun’s
energy is absorbed by Earth’s
atmosphere and clouds?
3. How much of the Sun’s
energy is absorbed by the
land and sea?
Heating of the Atmosphere
If we did not have gases to absorb solar
radiation, Earth would not be a place
where we could live
 This heating of the lower layer of the
atmosphere from radiation absorbed by
heat absorbing gases is called the
greenhouse effect
 … so just like plants grow better in a
greenhouse, all life on Earth is able to
flourish because of the greenhouse effect

Heating of the Atmosphere





The temperatures we experience are due to the
amount of heating of the atmosphere above us
and the ground and water around us.
Land heats and cools more rapidly than water
Land also reaches higher and lower temperatures
than water
The temperature of the land and water influences
the temperature of the air above it
This explains why inland areas experience greater
temperature variations than cities near large
bodies of water
Think about it!

City A is located on the Outer Banks of
NC and City B is located inland. Which
city would experience greater variations
in temperature and why?
Check-in Questions
What causes the transfer of energy in the from of heat
from one object to another?
2. What is the greenhouse effect? How does it affect life
on Earth?
3. Complete this chart
1.
Amount of the Sun’s energy that
reaches Earth’s atmosphere that
is reflected back into space
Amount of the Sun’s energy
absorbed by Earth’s atmosphere
and clouds
Amount of the Sun’s energy
absorbed by the land and sea
Complete the following sentence: Land heats
______________ than water.
5. As a result of what you said in #4, where are
temperature variations greater? (over land or over water)
4.
Final Project

For your final grade you will have both an
exam (don’t worry, we’ll be reviewing for
it) and a project

The project is set up so that you can pick
and choose the topics you would like to
review/work on
Science Museum
Each of you has been hired by a new
science museum that wants to open right
here in Eastern North Carolina
 To help the museum get set up for their
first exhibit THE EARTH AROUND US,
they’ve asked if you would please create
brochures to inform the public about
different Earth processes/ advertise the
museum

Project
Each of you will need to complete a
TOTAL of at least 300 “museum points”
 These can be done by doing any
combination of the brochures on the list
you have received
 AFTER you have successfully completed
300 points, there will be an extra credit
opportunity to choose a science video
that you believe should be shown at the
museum and why.

Project
Due dates
 Completed projects will be due when you
return from Christmas, however it is
STRONGLY encouraged that you
complete at least 150 points before
break…

◦ THE SOONER YOU GET IT IN, THE BETTER
Work Time

Vocabulary is due FRIDAY

This is also a good time to get started on
outlining your brochures
Exit ticket 11/30/10
1.
Which of the following is true?
a)
b)
c)
d)
2.
3.
Land heats less rapidly than water
Land heats more rapidly than water
Land reaches higher temperatures than water
Both b. and c.
What causes heat to be transferred from
one object to another?
On average, how much of the sun’s energy
that reaches the outer atmosphere is
reflected back into space?
Moisture, Clouds and
Precipitation
Chapter 18
Warm Up 12/1/10
1.
2.
◦
3.
Which heats faster: land or water?
What causes the transfer of energy (heat) from
one object to another?
Heat moves from objects with warm temperature
to cooler temperatures.
So – in which direction would heat move in each of
these situations: (draw arrows)
1.
2.
3.
Penguin
Pavement
Ice
icy water
the sun
water
What is the greenhouse effect?
On average, how much of the sun’s energy that
reaches Earth’s outer atmosphere is reflected back
into space?
6. Which has greater temperature variation: land or
water?
4.
5.
Objectives

Today I will be able to:
◦ Evaluate the most important gas in the
atmosphere.
◦ Compare and contrast saturation and relative
humidity.
Key Points - Moisture
Water vapor is the most important gas for
understanding atmospheric processes.
 Water vapor makes up 0-4 % of atmospheric
gases.
 Air that has reached its water vapor capacity is
said to be saturated.
 Warm, saturated air contains more water vapor
than cold air.
 Relative humidity is the ratio of air’s water-vapor
content to its capacity to hold water vapor at that
same temperature.

Water in the Atmosphere
Water exists in three different forms.
 What are they?

1. SOLID Examples: Snow, ice
2. LIQUID Examples: Rain, water
3. GAS Examples: Clouds, water vapor

How do each of these forms of water
influence weather?
Water in the Atmosphere

When it comes to understanding
atmospheric processes, water vapor is
the most important gas in the
atmosphere.

Why do you think water vapor is so
important?
Water in the Atmosphere

Even though water vapor is important, it only
makes up from 0 – 4% of the atmospheric
gases.
When have you felt water vapor at close to
4%?
 What about 0%?
 How do you know?

◦ Water vapor is the HUMIDITY that you feel in the
air!
Water in the Atmosphere

What do you think the word
“SATURATED” means?

What do you think it would mean if air is
Saturated?

Air that has reached its water vapor
capacity is said to be saturated.
Water in the Atmosphere

Warm, saturated air contains more water
vapor than cold air.
When have you noticed the humidity
more, in the summer or in the winter?
 That’s because warm air can hold more
water vapor!

Water in the Atmosphere
Relative humidity is the ratio of air’s watervapor content to its capacity to hold water
vapor at that same temperature.
 Relative humidity indicates how near the air is
to saturation, not the actual quantity of water
vapor in the air.
 Relative Humidity varies with temperature.
 Cooling air increases its relative humidity.
 Warming air decreases its relative humidity.

1% :2%
 1%:4%

2%: 3% (cooler) 2/3
 2%: 4% (warm) 2/4

Water in the Atmosphere

Relative Humidity –

Why does lowering the air temperature cause
Relative humidity to increase?
◦ Because colder air cannot hold as much water
vapor!

Why does increasing air temperature cause
relative humidity to decrease?
◦ Because warm air can hold more water vapor and it
will take more water vapor for it to become
saturated.
Check In Questions
Answer the following questions:
1. What gas is most important for understanding
atmospheric processes?
2. Water vapor makes up what fraction of
atmospheric gases?
3. Which holds more water vapor: warm air or
cool air?
4. Henderson has a humid climate. What are
evidences of humidity that you have seen?
5. How is the humidity different from the
summertime to the wintertime?
6. Why is the air in buildings so dry in the winter?
Matching- answer A, B or C for each
of the situations.
Situation
1. Water vapor is
added
2. Air temperature
decreases
3. Water vapor is
removed
4. Air temperature
increases
Change in Relative Humidity:
Increases
B. No change
C. Decreases
A.
Measuring Moisture

Invent a machine that measures Relative
Humidity and Water Saturation in the air.
Draw a picture of the machine
2. Write a detailed description of how the
machine works.
3. Create instructions for how to use the
machine.
1.

You will be judged based on creativity and
neatness. Be specific about how it works!
Brownie Ticket
Air that has reached its water-vapor
capacity is said to be:
a. Dry b. unstable c. stable d. saturated
2. The ratio of air’s water content to its
capacity to hold water at the same
temperature is:
a. Vapor pressure b. relative humidity c.
specific humidity d. wet adiabatic rate
3. Water vapor makes up what fraction
(%) of atmospheric gases?
1.
Warm up 12/2
1.
2.
3.
4.
5.
Water vapor makes up what percentage
of atmospheric gases?
What is the most important gas for
understanding atmospheric processes?
What is air called that has reached its
water-vapor capacity?
Which type of air can hold the most
water-vapor? Cold or warm?
Explain relative humidity.
Lifting Air - Objectives

Today, I will be able to:
- Describe how air is lifted to form clouds.
Key Points - Clouds
When air is compressed the air
temperature rises and the air molecules
move faster.
 Processes that lift air include orographic
lifting, frontal wedging and convergence.
 Examples of condensation nuclei include
dust, smoke and salt particles.

Lifting Air
When air is compressed the air
molecules move faster and the
temperature rises.
 Air compression causes changes in
temperature even though heat isn’t added
or subtracted.
 When air is allowed to expand, it cools.
 When air is compressed, it heats up.

Lifting Air
Cool, expanded air
Clouds form
because as you
go up in
elevation, it gets
colder.
Warm, compressed air
Cold air cannot
hold as much
water vapor so
it transforms
into clouds.
Lifting Air – Creating Clouds

When air expands to form clouds, the water
vapor is transformed to clouds by
condensation.

Generally, there must be a surface for water
vapor to condense on.

Condensation nuclei are tiny bits of
matter that serve as surfaces on which
water vapor condenses when condensation
occurs in the air.

Examples of condensation nuclei include
dust, smoke and salt particles.
Lifting Air
Four mechanisms that cause air to rise
are:
1. Orographic Lifting
2. Frontal Wedging
3. Convergence
4. Localized Convective Lifting

Lifting Air
Orographic Lifting
 Orographic lifting occurs when
mountains act as barriers to the flow of
air, forcing the air to ascend.
1.
Lifting Air
How does the relatively flat areas form clouds?
2.

Frontal Wedging
A front is the boundary between two
adjoining of air masses having contrasting
characteristics.
Lifting Air
Convergence
 Convergence occurs when two air
masses converge. The air flows together
and rises.
3.
Lifting Air
Localized Convective Lifting
 Localized convective lifting occurs where
unequal heating on earth’s surface causes
pockets of air to rise.
4.
Check In Questions
What happens when air is
compressed?
2. Name the 4 processes that lift air.
3. Why are condensation nuclei
important?
4. Name 3 examples of condensation
nuclei.
1.
Brochure
Create a handout that shows the different
ways air is lifted to form clouds.
 Front flap:

◦ Name of the handout
◦ Your name and class period

Inside flaps/back flap:
◦ Title each flap with the four ways air is lifted
◦ Draw a picture under the title on each flap
◦ Explain how air is lifted in your own words for
each of the flaps.
Brownie Ticket
1.
Which of the following occurs when air
is compressed?
a)
b)
c)
d)
2.
3.
Air temperature rises
Air temperature cools
Air molecules move faster
Both a and c
Name 2 examples of condensation
nuclei.
Which of the following is NOT a
process that lifts air?
a)
b)
c)
d)
Convergence
Orographic lifting
Divergence
Frontal wedging
Warm up – 12/3
What happens to air when it is
compressed? (2 things)
2. Name 3 examples of condensation nuclei
3. Explain orographic lifting.
4. Explain frontal wedging
5. When are days and nights equal in length –
during a solstice or an equinox?
6. The heating of the lower layer of the
atmosphere from radiation absorbed by
gases is called: ______________.
1.
QUIZ
Clouds Objectives

Today I will be able to:

Classify clouds based on shape and height.
Clouds

Yesterday we learned about how is lifted
to form clouds, today we are going to
learn about the different types of clouds
and how they are classified.

Clouds are classified based on their
form (shape) and height.
Clouds
Cloud types by FORM
 There are three basic forms of clouds. All
other clouds one of these three or are
combinations or modifications of them:
1. Cirrus
2. Cumulous
3. Stratus

Clouds by Form
1.
Cirrus (cirrus = “curl of hair”) are
clouds that are high, white, and thin.
Clouds by Form
2.
Cumulus (cumulus = “a pile”) are clouds
that consist of rounded individual cloud
masses.
Clouds by Form
3.
Stratus (stratus = “a layer”) are clouds
best described as sheets or layers that
cover much or all of the sky.
Clouds

Cloud Types by HEIGHT
1.
High Clouds – “Cirro”
Middle Clouds – “Alto”
Low Clouds – “Strato”
2.
3.

Most cloud names are a combination of
cloud type by form and by height.
Cloud Types and Precipitation
1. High Clouds
• Cirrus clouds are high, white, and thin.
• Cirrostratus clouds are flat layers of clouds.
• Cirrocumulus clouds consist of fluffy masses.
2. Middle Clouds – “Alto”
• Altocumulus clouds are round. They are larger and
denser than cirrocumulous.
• Altostratus clouds are uniform white to gray sheet
covering the sky with the sun or moon visible as a
bright spot.
Cloud Types and Precipitation
3. Low Clouds
• Stratus clouds are best described as sheets
or layers that cover most of the sky.
• Stratocumulus clouds have a rounded
bottom.
• Nimbostratus clouds are the main
precipitation makers.
- “Nimbo” means “rainy cloud”
 Cumulonimbus clouds cover low, middle
and high heights.
 These clouds are often associated with thunder
and lightning.
Cloud Classification
Check In Questions
1.
2.
3.
4.
5.
How are clouds classified?
Which cloud type is best described as
sheets or layers that cover much or all
of the sky?
Which term is used to describe clouds
of middle height?
Which type of cloud means “rainy
cloud”?
Which clouds are associated with
thunder and lightning?
Clouds Lab
Create a “sky” full of clouds!
Using the diagram on p. 519 as a guide, use the
cotton balls and chalk to create your sky.
You must have the following labeled in your sky:
High Clouds:
 Cirrocumulus
 Cirrostratus
 Cirrus
Low Clouds
 Nimbostratus
 Stratus
 Stratocumulus
 Cumulus
 Cumulonimbus
•
•
• Middle Clouds
 Altocumulus
 Altostratus
• Earth’s Surface
Brownie Ticket
Which term means “rainy cloud”?
1.
a.
b.
c.
d.
Stratus
Nimbus
Cirrus
cumulus
Which term is used to describe clouds of
middle height?
Which cloud type is best described as sheets
or layers that cover much or all of the sky?
2.
3.
a.
b.
c.
d.
Cumulus
Cirrus
Stratus
alto