Weather

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Weather
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Bell Ringer Day 1

• In your science notebooks, make a heading for a
  new section of notes for our unit of study on
  WEATHER.
• 1.) Pretend that your younger cousin, Becky, asks
  you to tell her what weather is. In your
  notebook, define WEATHER in your own words

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Bell Ringer

• Hot air or water_____
• a.) sinks b.) rises c.) does not move
• 2. What do we call the movement of hot water or
  air? convection

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What IS weather?! (share answers from Bell
Ringer)

• ?Weather is the state of the air and atmosphere
  at a particular time and place the temperature,
  wind, moisture, and atmospheric pressure.
• Examples
• ?1.) The weather will be hot and dry today.
• 2.) The hikers took shelter from the weather in a
  small cave.
• 3.) Make sure to check the weather before you
  pack for your trip.
• When you see the arrow symbol,?, you should be
  writing in your notes

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Day 1 Introduction

• What is the weather that we are experiencing in
  Bowling Green, KY today?

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• Using the chrome books, find a city in the United
  States that is having very different weather than
  we are today.

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WHY???

• 1.) Now that we have heard about other cities, in
  the same country that we live in that have very
  different weather patterns than us, how can we
  explain the difference??

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• Weather patterns are complex, and very difficult
  to predict because weather is caused by so many
  different factors.

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What causes weather?

• The number one cause of weather is ?uneven
  heating of the earths surface.
• The uneven heating causes temperature
  differences, which in turn cause air currents
  (wind) to develop, which then move heat from
  where there is more heat (higher temperatures) to
  where there is less heat (lower temperatures).
•  HOT AIR (moves to) ? COLD AIR

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What do we call the movement of hot air?
?CONVECTION
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1 cause of weather uneven heating

• ?The atmosphere thus becomes a giant "heat
  engine", continuously driven by the
  sun. High and low pressure areas, wind, clouds,
  and precipitation are all caused, either directly
  or indirectly, by this uneven heating and the
  resulting heat redistribution processes.
• ?HEAT IS ENERGY, WILL MOVE UNTIL EVERYTHING HAS
  THE SAME AMOUNT OF ENERGY, OR IS THE SAME
  TEMPERATURE

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Advanced Going Into More Detail

• Two main modes of this heat redistribution
• (1) VERTICAL heat transport Solar heating of the
  Earth's surface makes the atmosphere convectively
  unstable, causing vertical air currents to
  develop. This is what causes puffy-looking
  clouds, showers, and thunderstorms to form in
  warm air masses. (2) HORIZONTAL heat transport
  Because the Earth is a sphere, it receives more
  sunlight in the tropics, and less sunlight toward
  the North and South Poles. This causes horizontal
  temperature differences to develop, which in turn
  causes air pressure differences, leading to wind
  that transports heat from the tropics to the high
  latitudes. Together, this uneven heating in
  both the horizontal and vertical directions in
  the atmosphere causes everything that we perceive
  as "weather".

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What causes weather?

• ?Another factor that causes weather is WATER.
• ?During the water cycle, heat energy is
  constantly causing water to change states.
• List the 3 states of water put a over the
  state with the most energy, and a over the
  state with the least amount of energy
• The energy changes during the water cycle cause
  weather.

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CLOUDS PRECIPITATION

• ?Wind flowing over the Earth's surface causes
  evaporation of surface water.
• Does water evaporating gain or lose energy?
• Evaporation requires heat (water gains energy)
• How would water evaporating affect the
  temperature of the earths surface?

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CLOUDS PRECIPITATION

• Water evaporating would cool the surface of the
  earth.
• Where does water go when its evaporated from
  earths surface?
• After evaporating, water releases that heat
  higher up in the atmosphere when the water
  vapor condenses to form clouds and precipitation.
  
• Advanced FYI This primary mode of vertical heat
  transport is called "moist convection".

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Diagram of how water can cause weather In your
packet, draw this diagram, and label the
following 1. evaporation water gains energy,
2. surface cools, 3. condensation releases heat
energy
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The following photo from the Space Station shows
a large thunderstorm, which represents moist
convection transporting heat from the lower to
the upper atmosphere
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What causes weather?

• Now that we have seen an example of how water
  affects weather, we need to know some important
  terms
• Humidity the amount of water vapor or moisture
  in the air
• 2. Relative Humidity is the amount of moisture
  in the air compared to what the air can "hold" at
  that temperature

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Humidity

• How does humidity cause or affect weather?

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Air Pressure Air Masses

• The two causes of weather that we have learned
  about are uneven heating of the earths
  surface, water. Now, we will learn how
  meteorologists combine these two causes to
  predict weather.

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• Have you ever wondered how a day could begin
  warm, and you could wear shorts in the morning,
  and by the evening you need a heavy coat???

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Air Masses!

• ?Changes in weather are caused by the movement
  and interaction of air masses.
• Hot, Dry Air Cold, Moist Air WEATHER!

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Two main characteristics define air masses

• ?1.) Temperature
• ?2.) Moisture content
• The temperature and moisture content of air
  masses are abbreviated as two letters. The first
  letter is a lower case letter and is used to
  symbolize the overall moisture in the air. The
  second letter (capitalized), symbolizes the
  temperature.

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Example of air mass

• One example of an air mass continental tropical
  (cT)
• The air mass symbol cT tells scientists that
  the air is
• c continental, or formed over land, so it has
  less moisture than air formed over water.
• T Tropical, or formed in a warm area (close to
  equator)

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4 Types of Air

• continental air - c
• maritime air - m
• Tropical air - T
• Polar air - P
• Based on the names (above), can you describe each
  of the types of air ?

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Types of Air

• continental air  c Any body of air that forms
  over a large land area and has low moisture.
• maritime air  m Air that forms over a large
  body of water and is usually moist. Also called
  oceanic air.
• -Maritime air masses are unique because they
  usually stay the same resist change! Why do you
  think that is?

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• Tropical air T air formed in
  regions where the temperature is warm. A tropical
  air mass tells us the air is warm and formed in
  the lower latitudes (close to the equator).
• Polar air P air formed in regions where the
  temperature is colder.
• 1.) Compared to tropical air, where do you think
  Polar air forms?
• 2.) Pause for a moment, identify the opposite
  of each type of air.
• 3.) Why are Tropical (T) Polar (P) air
  capitalized, while Maritime (m) Continental (c)
  are lower case?

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Opposite Air Masses

•  Continental (formed over land) , opposite of
  Maritime (formed over water)
• -Maritime is AKA (also known as) Maritime
  front, MAMS, or oceanic air mass
• Tropical (is hot or warm), opposite of Polar
  (cold)

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Air masses Types of Air

• continental air - c
• maritime air - m
• Tropical air - T
• Polar air - P

• maritime tropical (mT)
• continental tropical (cT)
• maritime polar (mP)
• maritime tropical (cP)

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• 1. maritime Tropical (mT)
• 2. continental Tropical (cT)
• 3. maritime Polar (mP)
• 4. continental Polar (cP)

1. Moist Warm
2. Dry Warm
3. Moist Cold
4. Dry Cold

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• Scientists sometimes need a more extreme
  description for VERY cold air they call it
  Arctic air instead of Polar.

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What type of air mass would this be?
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• Can you guess what type of air forms off the
  north west coast of the U.S.A., by the state of
  Washington Canada?

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• Which types of Air Mass it will be is determined
  by where the air mass comes from not where it
  travels to.

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What type of air mass would form here?
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What type of air mass would form here?
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Atmosphere Definition

• The layer of gases surrounding Earth composed
  mainly of nitrogen and oxygen
• 78 nitrogen
• 21 oxygen
• 1 other

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Layers
http//www.fi.edu/wright/again/wings.avkids.com/wi
ngs.avkids.com/Book/Atmosphere/Images/atmos_layers
.gif
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Troposphere

• Where all plants and animals live and breathe
• Where weather takes place
• 90 of the mass of the atmosphere
• Thinnest layer
• Temp decreases with altitude

http//atschool.eduweb.co.uk/kingworc/departments/
geography/nottingham/atmosphere/pages/gfx/troposph
ere.jpg
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Stratosphere

• Ozone in this layer stops many of the sun's
  harmful rays from reaching the earth
• People can not breathe in this layer.
• Temperature increases as altitude increases
• Keeps air warm and protects life on Earth

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Ozone Layer

• Pale blue gas with a strong odor.
• 90 of all ozone is found in the stratosphere
• 10 is found in the troposphere
• Ozone is extremely important because it is the
  only gas that absorbs ultraviolet radiation from
  the Sun and protects the surface of the Earth and
  people from the damaging effects of UV rays

http//ess.geology.ufl.edu/ess/Notes/090-Ozone_Dep
letion/depl2.jpg
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Mesosphere

• Meso middle between strato and thermo
• Windstorms reach speeds of 320 km/h
• Temp decreases with altitude
• coldest layer (-93 degrees C)
• This is where we see "falling stars" meteors
  burning up as they fall to Earth

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Ionosphere

• An extension or a part of the upper mesosphere
  and lower thermosphere. So technically, the
  ionosphere is not another atmospheric layer.
• Composed of electrically charged particles
• Auroras take place in this area
• Radio waves are reflected by this layer

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Thermosphere

• Layer of the atmosphere which is first exposed to
  the Sun's radiation
• Temperatures are very high, but doesnt feel hot
  because particles dont transfer energy
• The air is very thin

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Exosphere

• Highest layer of the atmosphere. The air is very
  thin here
• Atoms and molecules escape into space

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Lets look at an animation

• http//earthguide.ucsd.edu/earthguide/diagrams/atm
  osphere/index.html

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Air Pressure
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HIGH AND LOW PRESSURE AREAS

• Uneven heating of the earths surface causes high
  and low pressure areas to develop.
• Wind is caused by air flowing from an area of
  high pressure to an area of low pressure.
• -Winds direction is influenced by earths
  rotation, which makes things complicated!!!HIGH
  ? LOW
• Wind wants to flow from high to low pressure
  areas, but the rotation of the earth prevents this

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• So, instead, wind flows AROUND areas of high and
  low pressure.
• Clockwise around high pressure, counter clockwise
  around low pressure
• The diverting effect of earths rotation is
  called the Coriolis effect

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Advanced FYI

• The horizontal transport of heat by wind from low
  (equator) to high latitudes (like Greenland) is
  strongly influenced by the Earth's rotation,
  which prevents the wind from flowing directly
  from high pressure to low pressure, and instead
  causes the wind to flow around high and low
  pressure centers. 

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Coriolis Effect

• The following example shows how the wind flows in
  the Northern Hemisphere...in the Southern
  Hemisphere, the wind flows in the opposite
  direction around high and low pressure areas.

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• This diverting force is called the "Coriolis
  effect".
• The spiral shape of cloud systems can be clearly
  seen from space, such as in this famous photo
  taken by Apollo 17 astronaut Harrison Schmitt,
  and is evidence of the Coriolis effect.

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I want students to use DE to get this info.

• How Does the Movement of Air Masses Affect
  Weather? (fronts)  
• Meteorologists focus a great deal on the study
  ofweather patterns known as fronts. Fronts are
  the boundaries between large masses
  of air. Airmasses form over large areas
  of Earths surface and take on the
  general temperature and moisture characteristics
  of the area over which they form. As an air mass
  moves across a region, the location of
  a front will change. Air masses are generally
  defined by their overall temperature andair
  pressure. As these air masses move and collide
  with one another, different types ofweather can
  occur along a front.

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Advanced Big Picture

• All of these horizontal and vertical heat
  transport processes produce complete atmospheric
  circulation "cells". This is a consequence of the
  fact that for all of the air transporting heat
  from higher to lower temperatures, there must
  also be a return flow of air in the opposite
  direction. 

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Advanced Big Picture

• For instance, for all of the air rapidly rising
  within a thunderstorm, there must be an equal
  amount of air sinking elsewhere. This sinking
  occurs over a much broader area than the strong
  updrafts in the thunderstorm, and the rate of
  sinking is more slower. This is why you feel
  turbulence when flying through clouds, but not so
  much in the clear areas around the clouds. The
  distances involved in the circulation cells is
  typically tens of miles. 

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General Big Picture

• The movement of air from areas of high to low
  pressure forms atmospheric circulation cells.

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Conclusion (adv gen)

• So, when you experience a clear day without a
  cloud in the sky, you are in the descending
  branch of an atmospheric circulation cell. That
  descending air is being forced downward by rising
  air in precipitation systems hundreds or even
  thousands of miles away. Then, because these
  circulation cells tend to travel, in a day or two
  you find yourself in the ascending branch of a
  circulation cell, with clouds and rain (or
  snow). If all this sounds complicated, that's
  because it is. But remember, all of this
  complexity we experience as "weather" is
  ultimately the result of uneven heating of the
  Earth by the sun, and the atmosphere continuously
  'trying' to reduce the resulting differences in
  temperature.

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