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Bellringer-Day 01
What do you think of when you hear the word
“atmosphere?”
What events do you think take place within
the atmosphere?
Do you know any layers/parts of the
atmosphere? If so, what?
Introduction to the
Atmosphere: Structure and
Composition
Our atmosphere
Earth’s atmosphere = the layer of gases that surround the planetVery thin layer, relative to size of planet Atmosphere:
Absorbs solar radiation
Burns up meteors
Transports and recycles water, and other chemicals
Moderates climate
Composition of the Atmosphere
Main Components
◦ 78% nitrogen
◦ 21% oxygen
◦ 1% argon
◦ Traces of other gases:
water vapor
carbon dioxide
Methane
pollutants
Layers of the Atmosphere
The atmosphere is divided into four layers based on temperature:1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere
As we continue…
Fill out your Layers of the Atmosphere Chart in your notes
•Be sure to include• Temperature change according to elevation
• Special characteristic of that layer
• Drawing which helps you remember the layer name with its characteristics
The Troposphere
The bottom layer, at Earth’s surface
11 km high.
Temperature decreases with altitude.
Where weather occurs
The Stratosphere
◦ Next layer up (11–50 km).
◦ Temperature increases with altitude.
◦ Contains “ozone layer.”
◦ Why do you think planes fly in the stratosphere?
The Mesosphere
Third layer up
(50–90 km).
Temperature
decreases with
altitude.
The Thermosphere
Top layer (90–500
km).
Very thin air;
mostly lightweight
elements.
Very hot.
Atmospheric layersTemperature and other characteristics vary with altitude.
Figure 11.3
Tropopause
marks boundary
between
troposphere and
stratosphere.
Layers don’t
mix.
Ozone layer
Ozone layer
Not really a layer (it’s part of the stratosphere), but a region of higher-than-normal ozone concentrations (which are still very low)
~17–30 km altitude
Ozone = O3—molecule of 3 oxygen atoms
Absorbs ultraviolet (UV) radiation from sun, protecting organisms on surface from radiation damage
Exit Ticket
Create a diagram of the atmospheric layers, from the Earth up.
In each layer, write the defining characteristic of that layer
Create a pie chart that describes the amount of each atmospheric gas
Bellringer: Day 021. What are the 4 layers of the
atmosphere, from the layer closest to Earth up?
2. Which layer is where weather occurs?
3. In which layer is the ozone layer located?
4. What does the ozone layer do? In other words, why is it important to us on Earth?
What is Meteorology?
The study of weather, climate, and atmosphere processes
How Does Weather
differ from Climate?
Weather is constantly changing and it refers to the state of the atmosphere at any given time and place
Climate is based on observations of weather that have been collected over many years to help describe a place or region
Weather Vs. Climate
Weather Examples
Temperature
Pressure
Cloudiness
Humidity
Climate Examples
Seasons
Weather patterns over time/years
First, we’re going to talk about weather.
Later, we’ll talk about climate and
climate change!
Air Density Like most substances, cold air is more dense than warm air
Cold air will sink, hot air will rise….sound familiar??
Air Pressure Demo!
Pressure Systems
Low pressure –warm air rises
Poor Weather-Clouds and
precipitation
High pressure – cool air sinks and
spreads
Fair weather
Wind is caused by the movement of air
molecules
Cool dense air sinks, forcing warm, less
dense air upward
Wind
Global Winds
The atmosphere balances itself
by acting as a giant heat-
transferring system
It moves warm air to the poles
and cool air towards the
equator
Jet Streams –
High altitude, westerly winds
Responsible for most of our
weather in our country!
Air Masses
Air masses are large bodies of air that take on characteristics of area they
cover (land and water)
Four Basic Types of Air Masses
cP – Continental Polar
•dry and cool
•cold and dry in winter
and summer
cT – Continental Tropical
•dry and hot
•hot, drought-like
conditions
mT – Maritime Tropical
•wet and warm
•source of precipitation in
the United States
mP – Maritime Polar
•wet and cold
•mild, humid, unstable
cold air from Canada
Fronts
Fronts are the
narrow regions
separating two air
masses
Warm Front
Warm air displaces cold
air
Weather Conditions:
Light to moderate rain
Cold Front
Cold air displaces
warm air
Weather Conditions:
Thunderstorms
Stationary Fronts
The surface position
of the front does not
move
Do not displace
Occluded Front
• Warm squeezed
between cold
Can you name the fronts?
Exit Ticket-Did the information “stick?”1. What would be the primary reason that planes fly in the stratosphere, the
second-lowest layer of the atmosphere? a) To avoid storms and other weather events b) To receive better radio communication c) To fly at supersonic speeds without air resistance d) To avoid changes in air pressure
2. The earth’s atmosphere is mainly composed of which three gases?a) Argon, nitrogen and oxygenb) Carbon dioxide, helium and nitrogenc) Argon, methane and oxygend) Helium, oxygen and radon
3. In which atmospheric layer do thunderstorms occur?a) Thermosphereb) Mesospherec) Stratosphered) troposphere
Bellringer: Day 03
▪ Identify the states in which the fronts are
occurring. What types of fronts are they?
Water in the Atmosphere
Precipitation is any form of water that falls from a cloud.When it comes to understanding atmospheric processes, water vapor is the most important gas in the atmosphere
Humidityamount of water vapor in air.
Relative Humidity
Water vapor in the
air compared to how
much water vapor
the air is capable of
holding
Saturation
▪ The state when air contains the maximum quantity of water vapor that it can hold at any given temperature and pressure.
▪ Saturated warm air contains more water vapor than saturated cold air
Dew PointDew point is the temperature to which air would need to be cooled to reach saturation.
http://www.youtube.com/watch?v=S8W-
xl4mcJ8
Dew on a Spider Web
Measuring Humidity
▪ Instrument: Hygrometer▪ Psychrometer : a type of
hygrometer consisting of two identical thermometers mounted side by side
▪ Dry bulb: give the present air temperature
▪ Wet bulb: has thin wet wick tied around the end
Cloud Formation
▪ Condensation Nuclei – small particles in atmosphere
which water condenses around
– Millions = cloud
▪ Coalescence – droplets collide, become bigger
▪ Precipitation – droplets become too big and fall
CloudsClouds are classified on the basis of their form and height.
http://www.youtube.com/watch?v=32uFVssBs6E
Exit Ticket-Did the information “stick?”
1. What about the cloud in the jar is similar to real cloud
formation?
2. How is relative humidity different from humidity? Why is it
that warmer seasons tend to be more humid than colder
seasons?
Bellringer: Day 041. Explain how clouds form in 3 steps.
2. What is the difference between humidity and relative humidity? Relate relative humidity to cold vs. warm air.
3. Explain what’s happening in the morning when dew drops are forming on the grass.
Practice: Reading Fronts
Weather Models In reading weather data, we can find all of the following through reading a
weather model
Temperature
Dew Point
Cloud Cover
Present Weather
Wind Speed
Wind Direction
Location
Atmospheric Pressure (mb)
Using Weather Models
Temperature
on the model
is measured
in degrees
Fahrenheit
Using Weather ModelsCurrent weather
is represented
by any number
of symbols:
Using Weather ModelsDew point is in
Fahrenheit
Cloud cover is
represented by the
amount of the circle
that is blacked out
Using Weather ModelsPressure measured in
millibars- also measured
by isobars on the map
For the pressure,
remember to add the
decimal point
between the 2nd & 3rd
digit, then put a 9 or
10 in front of it. The
acceptable range of
pressures is 960mb
to 1040mb.
Using Weather Models
Wind speed is measured
by lines
-Long lines are 10 knots
-Short lines are 5 knots
Using Weather ModelsWind direction is
designated as the
area the wind is
blowing from!
The arrow is pointing NE,
so the wind direction is
“from the NE”
What’s Taking Place?
Pressure Differences Isobars
lines on a map that connect places of equal air pressure
A pressure gradient
The spacing of isobars
indicates the amount
of pressure change
over a given time
Isobars Closely spaced isobars:
indicate a steep pressure
gradient and high winds.
Widely spaced isobars:
indicate a weak pressure
gradient and light winds.
High and Low Pressure SystemLow Pressure Centers High Pressure Centers
Centers of Low Pressure High Pressure
AKA Cyclones Anti-cyclones
Pressure
Behavior
Pressure drops Pressure increase
Wind Behavior Winds blow
counterclockwise
Winds blow outward and
clockwise
Weather
Associated
Severe and stormy Fair and Sunny
Symbol “L” that is RED “H” that is BLUE
What’s Taking Place?
Seasonal Weather Why do we have different weather in different seasons?
Why do we even have the seasons? What is the cause?
Weather?
Climate?
Bellringer-Day 05• Using the station below, answer the following:
– In what direction is the wind blowing?
– Is the wind strong or weak? How do you know?
– Is it clear, partly cloudy, or cloudy?
– What is the current temperature? And dew point?
SEVERE STORMS
THUNDERSTORMS, TORNADOS, AND HURRICANES
Thunderstorms• Generates lightning and thunder
• Frequently produce gusty winds, heavy rains, and hail
– 45,000 a day across the world
• Lightning: results from the build up and discharge of electric energy between positively charged ground and negatively clouds.
• Thunder: the sound of rapidly expanding gases usually associated with lightning
Development of Thunderstorms
• Warm, humid air rises in unstable environment
• Uplift carries warm, moist air into cooler part of atmosphere
• 3 Stages
–Cumulus Stage
–Mature Stage
–Dissipating Stage
Thunderstorm Development• 1. Cumulus Stage-Precipitation will stay
uplifted until heavier than uplift force
Thunderstorm Development
• 2. Mature Stage-Downdrafts throughout the cloud (cold air)
• 3.Dissapating Stage-Storm dies
Thunderstorm Development
https://www.youtube.com/watch?v=NxWbR60tFlg
Tornados• Take form of rotating column of air called
vortex
• Uplift turns vortex vertical
https://www.youtube.com/watch?v=2ajShQpzBus
https://www.youtube.com/watch?v=006guBgSf14
Tornado Intensity
• Pressure inside lower than outside
– Air rushes in to equalize pressure
– Winds may reach 480 km/h (300 mph)
Watch vs. Warning
• Tornado Watch-The conditions are favorable for a tornado to form. People in the area should remain cautious and listen for updates.
• Tornado Warning-A tornado is imminent and has either been sighted or picked up on radar. People in the area should take cover immediately.
When finished…
• http://cimss.ssec.wisc.edu/wxfest/Tornado/tornado.html
– Create a tornado
• http://www.nssl.noaa.gov/education/svrwx101/tornadoes/
– Read about tornados
