Transcript Unit 5- Air, Weather, and Climate

Unit 5- Air, Weather, and Climate
Lesson 2- Layers of the Atmosphere
Atmosphere- a blanket of gases that surrounds
Earth and certain other planets
-What is the atmosphere made of? GAS!
-It has several different layers- classified by the
following◦ Temperature
◦ Density-the concentration of matter in an object
or part of an object
◦ Air pressure-the result of the weight of air in the
atmosphere pressing down on earth
◦ They are all at different altitudes-the height of
an object above the surface of the earth
The Layers of the Earth’s
Atmosphere
EXOSPHERE
THERMOSPHERE
MESOSPHERE
STRATOSPHERE
TROPOSPHERE
The Atmosphere
• The atmosphere consists of layers of air that surround the
Earth. Some of the “air” is oxygen, which we breathe, but
there are also many other gasses, dust particles, and
even some water vapor mixed into the air.
TROPOSPHERE
The troposphere is the layer closest to the surface of
Earth. Nearly all life and all weather occur in this layer.
The air thins in this layer and is denser than in other
layers. In this layer, the higher up from Earth’s surface
you go, the colder it gets. The peak of Mt. Everest is
near the top of this layer.
STRATOSPHERE
The temperature in this layer becomes
warmer. The air is thinner and drier
than in the previous layer.
MESOSPHERE
The mesosphere is the coldest layer of the atmosphere.
When meteoroids from space enter our atmosphere, this is
the layer in which they usually burn up. That might be
surprising because it’s a pretty thin layer.
THERMOSPHERE
Temperatures in the thermosphere are very
high, more that 2000 degrees Fahrenheit. This
is where space begins. The International Space
Station orbits Earth in this layer.
EXOSPHERE
The exosphere is the outermost layer of Earth’s
atmosphere but there is no exact dividing line
between this layer and space.
-More about OZONE-
-It absorbs rays of damaging ultraviolet
(UV) light coming from the sun.
- In large doses, ultraviolet rays can harm
skin, causing sunburn, aging, and skin
cancer. UV light can also damage eyes.
-Recently, data showed some destruction
of the ozone layer caused by man-made
chemicals called chlorofluorocarbons or
CFCs.
-With less ozone in the stratosphere,
more harmful UV rays can reach Earth’s
surface.
Lesson 3- Conduction, Convection, &
Radiation
How ‘Heat’ Moves
Define “Energy”:
The ability to do work or cause change.
What is the basic unit of measure for
energy?
Joules.
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How ‘Heat’ Moves
Define “Heat”:
Heat is the movement of thermal
energy from a substance at a higher
temperature to another substance at
a lower temperature.
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The Nature of Heat
Heat moves in only one direction:
Under normal conditions and in nature, heat energy will
ALWAYS flow the warmer object to the cooler object.
Heat energy will flow from one substance to another
until the two substances have the same temperature.
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How ‘Heat’ Moves
Thermal energy in the form of heat can
move in three ways.
Conduction
Convection
Radiation
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Conduction
CONDUCTION:
The transfer of heat from one particle of
matter to another by direct particle to
particle contact.
◦
◦
Conduction occurs primarily in solids because the
particles are tightly packed together.
The particles themselves DO NOT change positions.
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Conduction
Example: A metal spoon in a pot of water being heated on an
electric stove.
a. First, the electrical energy is converted to
thermal energy by the stove.
b. The rapidly vibrating particles of the hot
electric coil collide with the particles of the
cool pot.
c. Heat energy is transferred, causing the particles
in the pot to vibrate faster.
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Conduction
d. The rapidly vibrating particles of the pot now collide
with the particles of the water at the bottom of the
pot.
e. The water particles absorb energy and vibrate and
flow more rapidly and its temperature increases.
f. Now, the energetic (hot) particles of water collide with
the particles of the submerged end of the spoon.
g. As the particles of the spoon absorb energy and
vibrate more rapidly. The temperature of the spoon
increases.
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Conduction
h. As the particles at this end of the spoon absorb
energy and vibrate faster they collide with
other particles in the spoon. As they collide,
energy is transferred to the other particles
(similar to momentum) and they begin to
vibrate more rapidly.
i. This process of conduction is repeated all along
the metal spoon until the entire metal spoon
becomes hot.
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Conduction
Brainstorming:
What are other examples
of conduction?
Application:
Describe the process of
conduction when you place a hot spoon
into a bowl of ice cream.
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Convection
Convection: the transfer of thermal
energy (heat) through the bulk
movement of matter.
◦ Convection occurs in FLUIDS (liquids and
gases).
◦ Convection produces CURRENTS in both gases
and liquids.
◦
Thermal Energy heat is carried by the particles as
they move from one location to another.
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Convection
Example: Heating water:
a. When the water at the bottom of the pot
(nearest the burner) is heated, the particles
absorb energy by conduction as they touch the
hot pot.
b. The water particles vibrate more rapidly.
c. The particles also move farther apart and the
hot water becomes less dense than the
surrounding cool water.
d. This causes the heated (hot) water to rise.
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Convection
e. The surrounding denser cooler water is forced
downward near the burner by the rising hot
water.
f. This process continues to repeat.
g. This FLOW creates a circular motion known as
a convection current .
Application: How do convection currents
form in a room when the heater is turned
on?
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Convection
The warm air from the heater vent will rise. Why?,
◦ The warm air is less dense than the surrounding
cooler air.
The cool air is pushed down by the rising warm air.
What is the best location for a heat vent in a room and why?
Near the ceiling or the floor?
Floor:
Because the warm air will rise to the ceiling.
How about the return vent?
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Convection
Convection currents occur in the environment
as well. They produce:
◦ Global winds that contribute to Earth’s
weather.
◦ Ocean and lake currents
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Convection
Brainstorming:
On a hot summer day the
breeze near the beach blows toward the
water. However, later in the day the
breeze reverses direction and blows
toward land and will get increasingly
stronger. Why?
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Convection
Answer:
In the morning the water may
be warmer than the sand causing the air
over the water to rise.
In the afternoon, the sand has
become much hotter than the water and
the air above it rises. The air over the
water rushes in to fill its void causing a
wind.
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Radiation
Radiation: the transfer of (thermal) energy
by electromagnetic waves.
◦ Radiation does not require matter to transfer
thermal energy.
◦ All the sun’s energy that reaches Earth travels
through millions of kilometers of empty space (a
vacuum).
◦ All matter can radiate energy.
◦ You feel the radiation of thermal energy from a
bonfire, a heat lamp and a light bulb.
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Radiation
Other examples of the transfer of heat by
Radiation:
a.
Charcoal grill.
b.
Hot tin roof.
c.
Burner on a stove top.
d.
?
e.
?
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Radiation
Key Point:
For radiation to be felt as heat it
must first be absorbed by a material.
Example: Why do blue jeans feel hotter in the
sun than a yellow shirt, even though they
are both exposed to the same amount of
sunlight?
◦ The blue jean fabric absorbs more radiant
energy from the sun than the yellow shirt
because of its dark color.
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Conduction, Convection & Radiation
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Energy from the Sun
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Convection, Conduction & Radiation
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The Nature of Heat
What happens when you put ice in a warm
soft drink?
◦ The heat energy moves from the soft drink
into the ice by conduction (particle to particle
contact) causing the ice to melt.
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Review
Describe the three kinds of heat transfer.
a. Conduction – transfer of heat energy from
one particle to another by direct contact.
(Primarily in solids)
b. Convection – transfer of heat energy in fluidsgases and liquids) through the bulk movement
of matter from one place to another.
(Produces currents)
c. Radiation – transfer of energy through
electromagnetic waves. (Matter is not
required!) (Radiant & infrared radiation from
the sun)
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Conduction
Direct contact of
particles
Solids/liquids/gase
s
The handle of a
cooking utensil
Radiation
• Transfer of
energy by
waves
• Only radiant
energy that
is absorbed
becomes
thermal
energy
• Lightbulb
• Fireplace
Convection
• Transfer of
energy by
bulk
movement of
matter
(fluids)
• Currents
(wind,water)
• Hot air
balloon
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Contrast:
Conduction
Convection
Radiation
•Direct contact of particles
•Solids/liquids/gases
•Solids -good conductors
•Gases -poor conductors
Conduction
•Transfer of energy
by waves
•Only radiant energy
that is absorbed
becomes thermal
energy
•Shiny/light colorsreflect
•Dull/dark colorsabsorb
Radiation
•Transfer of energy by
bulk movement of
matter (fluids)
•Currents (wind,water)
•Hot air balloon
Convection
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Lesson 4- Daily Weather
Weather- the day-to-day conditions of
an area, including the temperature,
wind direction and speed, air pressure,
relative humidity, and precipitation
-When we mention temperature, we
are referring to a measure of energy
on earth.
-Since earth’s shape is a sphere,
certain areas “bulge.” These areas
receive the sun’s energy more directly
than locations north and south of the
bulge. This makes the heating of earth
very uneven.
The Water Cycle
-water exists in three states: solid, liquid, and
gas.
-heat makes molecules move faster and
spread out.
-Adding heat energy melts ice or causes liquid
water to evaporate into water vapor.
-Making something cool slows down
molecules.
-Removing heat energy makes water vapor
condense to a liquid, or makes liquid water
freeze into ice.
-heat from the sun makes surface water
evaporate.
-Condensation cools water vapor to form
clouds or fog.
-Precipitation occurs when water falls back to
earth as liquid rain, sleet, hail, or snow
Humidity
Humidity-is the amount of water
vapor in the air at any one time and
depends on temperature. Warmer air
can hold more water than cooler air. If
there is a lot of moisture in the air
(high humidity) and air temperature is
low, water vapor will condense to form
clouds.
Relative Humidity- is the amount of
moisture in the air compared to the
amount of moisture air can hold at its
current temperature. When the
relative humidity is 100 percent, water
vapor can condense into clouds.
Dew Point- the temperature at which the
water vapor in the air would begin to
condense to liquid, if the air were cooled to
that temperature
Air Pressure-Water molecules in air are lighter than other
gases in air.
-Warm, humid air, full of water vapor is less
dense than dry air and therefore has a lower
air pressure.
-The air in the middle of a low-pressure system
is less dense than the air around it, so it
“floats” upward.
-As the air rises, it cools. Water vapor begins to
condense and form clouds. This may lead to
precipitation, such as rain or snow.
-That’s why a low-pressure system usually
means that cloudy or rainy weather is on the
way.
Lesson 5- Air Circulation
Do you know what the windiest
city in the U.S. is?
What is the least windy city in
the U.S.?
A) Chicago, Illinois
A) Talkeetna, Alaska
B) Mount Washington, New
Hampshire
B) Scottsdale, Arizona
C) Oklahoma City, Oklahoma
C) Kansas City, Missouri
Lesson 5- Air Circulation
Do you know what the windiest
city in the U.S. is?
What is the least windy city in
the U.S.?
A) Chicago, Illinois
A) Talkeetna, Alaska
B) Mount Washington, New
Hampshire
(average wind speed only 5 mph!)
(average wind speed over 35 mph!)
C) Kansas City, Missouri
C) Oklahoma City, Oklahoma
B) Scottsdale, Arizona
-Wind is simply air that is moving more or less
horizontally because of differences in air
pressures.
-Pressure that’s higher in one place will push
from an area of high pressure to an area of low
pressure.
-Air Gradient- the change in air pressure over
a given distance
-When two masses are far apart, the change in
air pressure occurs over a wide area.
- Air moves slowly from high to low pressure.
-Once the wind starts to blow, it is affected by
the rotation of the earth.
-Every point on earth’s surface makes one
rotation per day.
-Certain parts of the earth are actually rotating
faster than others.
The Coriolis Effect
- Coriolis Effect- the curved movement of air
or water caused by the rotation of the Earth
-Winds move in convection cells north and
south of the equator.
-If earth did not rotate, wind would always
blow down from the polar regions along the
surface, headed for the equator.
Different types of Air
Circulation-The speed is dependent on how
close to the poles they are
-The speed is slower at the poles
Lesson 6- Air Masses
Air Masses-a body of air covering a relatively
wide area, with about the same properties
through any horizontal section
-Different types of air masses exist all over the
world.
-They are classified by temperature and
moisture both of which have a lot to do with
where they form
-air masses develop near the poles and warm,
or tropical air masses develop near the
equator.
-Drier air masses form over land while humid
ones form over water.
4 types of Air Masses that affect the US
Continental tropical (cT): warm
and dry
Maritime tropical (relating to the
sea) (mT): warm and humid
Continental polar (cP): cold and
dry
Maritime polar (mP): cold and
humid
Warm Air Masses-2 types
-Continental and Maritime air masses are
warm
-maritime tropical air masses form over water,
they are more humid.
- When they reach land, they will bring rainy or
muggy weather and eventually dry out and
become a continental air mass.
-Since dry air is denser than humid air, a
continental tropical air mass has greater
density and higher air pressure.
Cold Air Masses- 3 types
-North
America is affected by
three types of cold air masses◦ continental polar- cold and dry
◦ maritime polar- cold and
humid
◦ Arctic- extremely cold and dry
Air Masses on the Map
-A dense continental air mass is called a
“high.” A high is a high-pressure area of dry air.
-Less dense maritime air masses are called
“lows.” A low is a low-pressure area of humid
air.
-When a weather forecaster announces a low
heading your way, you should get ready for
some wet weather.
-That “low” on the weather map refers to a
low-pressure air mass that has a lot of
humidity.
Lesson 7- Weather Fronts
-If two air masses with different temperatures or humidity levels meet, they do not
immediately mix or blend.
-Instead a line or boundary forms between them. This boundary is called a front.
Cold front- the zone separating two air masses, Warm front- a transition zone between a mass of
of which the cooler, denser mass is advancing
warm air and the colder air it is replacing
and replacing the warmer
-Weather at a warm front is often drizzly. Warm
-Cold air is denser and so it pushes in quickly
air will rise above the cooler air because it is less
under warm air. The warm air cools to its dew
dense, and then it will cool.
point and clouds form. Cold fronts can bring
dramatic weather such as large thunderclouds -The moisture in the warm air will form clouds
and then fall as precipitation.
and storms.
Stationary Front- a front
between warm and cold air masses
that is moving very slowly or not at all
-The air masses may be moving along
the boundary between the two fronts,
but the boundary itself moves only
slowly, if at all.
-Gray skies, rain, or snowy weather
may last a long time near a stationary
front. Winds may also blow along this
boundary.
Occluded Front-a front that
forms when warm air is wedged
upward between two cold fronts
-in an occluded front, there are clear
divisions between cold air, cool air, and
warm air.
-
Lesson 8- Meteorology
Hurricane Katrina
- A category 5 hurricane that hit the US in 2005
-1,836 people lost their lives
-Damages were estimated at $82.billion
-Meteorologists (scientists who study weather
and reports on weather conditions) at the
National Hurricane Center (NHC) used tools
such as radar and satellite to track the storm’s
path.
-As the storm grew to massive size and
changed its path, the NHC adjusted hurricane
warnings to cover wider areas, saving lives all
across Mississippi, Louisiana, and Alabama.
Meteorology Tools
A barometer is a tool that measures air
pressure. Air pressure measurements can
provide information about developing winds.
A hygrometer measures humidity. As you
know, when air masses meet, water vapor in
the air can condense and form precipitation.
Predicting Weather
-Once weather data is collected,
meteorologists develop weather maps where
they can see how air masses are approaching
one another.
-By comparing a current map with maps from
earlier in the day or week, meteorologists can
track the movements of air masses and fronts.
-Then they can create a forecast of weather for
the next few days.
-On the map to the right, “H” and “L” are used
to show areas of high and low pressure.
-The isobars, or lines around them connect
areas of equal pressure. Isobars look a lot like
contour lines on topographic maps but
connect areas of equal air pressure instead of
elevation.
-Notice that around the center of an “L,”
pressure increases as the bars move away
from the center. It’s the opposite around an
“H;” pressure decreases farther away from the
center.
Fronts
-A warm front brings drizzly weather.
-A cold front can cause heavy rain, thunder,
and lightning.
-A stationary front may produce rainy or
snowy weather for several days.
-An occluded front can cause light to heavy
precipitation that may last several days.
Questions!
1) What conditions are causing rain in Kansas
City?
2) Will the rain over Portland last a long or
short time? How do you know?
3) In a few days, will New York be sunny or
rainy?
Questions!
1) What conditions are causing rain in Kansas
City? Low-pressure air combined with a warm
front. The low-pressure air may already be
humid, so water in the warm front air is
cooling, condensing, and forming rain.
2) Will the rain over Portland last a long or
short time? How do you know? A long time
because there is a stationary front there.
3) In a few days, will New York be sunny or
rainy? New York will most likely be rainy as the
cold front and low-pressure air move in.
Lesson 11- Weather and Climate
Weather and Climatewhat’s the difference?
Weather- the day-to-day conditions of an area,
including the temperature, wind direction and
speed, air pressure, relative humidity, and
precipitation
Climatologist- a scientist that studies long-term
weather patterns, summarize the data and
calculate averages to describe the climate of a
location.
Climate- the long-term pattern of weather over
time for a particular area, including temperature
and precipitation
-An average is found by adding up all
measurements in a certain category such as
temperature, and then dividing by the number of
measurements you have.
-The local weather is what determines the
climate of an area.
- The weather can change on a daily basis, but
the average weather conditions over the long
term are known as an area’s climate.
-Average precipitation is also a way to
characterize, or describe climate. Average yearly
precipitation is the average of 12 months’ worth
of measurements of rain and snow. Locations
having a similar pattern of temperature and
precipitation have a similar climate though they
may be far apart.
3 major climate zones
Polar Climate Zone
-Polar climates have short summers and long,
dark winters.
-In the winter, the sun does not rise above the
horizon.
-During that period, the sun rays can not heat
up the ice enough to melt it.
-Because all the moisture is trapped in the
snow and ice, air in polar climates can be as
dry as that in a hot desert.
-In polar climates, no month has an average
temperature higher than 10°C (50°F).
Tropical Climate Zone
-Tropical climates are close to the equator,
mostly at latitudes less than 15 degrees,
where it is generally hot and humid all yearround.
-This zone experiences heavy rainfall during
the wet season.
-The combination of warmth and moisture
promotes the growth of lush forests.
- In tropical climates, the average monthly
temperature is higher than 18°C (64°F).
Temperate Climate Zone
-Located between the tropical and polar
regions, temperate climates typically have
distinct seasons and variable weather.
-One day may be sunny, the next day cold and
rainy.
-While polar and tropical zones contain
extreme climates, a temperate climate falls
between the climates of the other two zones.
-Warm, temperate climates cover almost half
the eastern United States and sections of the
West Coast.
-The average temperatures of the coldest
month are between 18°C (64°F) and –3°C (27°F
More Climate Zones?
-Since ancient times, climate zones
have been described as polar,
temperate, and tropical.
-However, in the early 1900s,
Dr.Wladimir Köppen, a German
meteorologist and climatologist,
developed more specific ways to
classify climate.
-He used temperature and
precipitation data to identify climate
zones and labeled them with a letter.
Lesson 12- Factors Affecting Climate
Location, Location, Location!
-Climate
and latitude are closely
related. Remember that because
of earth’s shape, radiation from
the sun heats its surface
unevenly.
- Locations closest to earth’s
“bulge” at the equator generally
have a warmer climate than
places at higher latitudes
By the Sea………..
-Coastal areas are generally windy.
- Land warms up faster than water
and radiates and conducts some of its
energy faster than the water does.
-During the day, the air above the land
heats more quickly and becomes
warmer than the air above the sea.
-Differences in air temperature over
sea and land will get a wind going.
-Ocean winds can carry a great deal of
moisture with them and can bring rain
and fog over inland areas.
-The climate of the Pacific Northwest
in the United States is greatly affected
by ocean winds that bring moisture to
the region's huge forests.
Ocean Currents
-Ocean currents affect the temperatures
of some regions. Some ocean currents
carry warm water into the north.
-The British Isles in western Europe, for
example, have a warmer climate than
other areas at the same latitude, such as
Labrador, Canada. A current called the
Gulf Stream brings warm water to the
British Isles.
-The Gulf Stream helps keep the climate
warmer than it would be otherwise.
-Other currents carry cold water away
from polar regions and make the
climate of the areas they travel to
colder than it would be.
-Currents can warm or cool the air
over them. The wind can carry that air
into neighboring land areas
Altitude
-At higher altitudes, the air is less
dense. When air loses density, it also
loses heat.
-So, the higher the altitude, the cooler
the air temperature.
-Regions that are very mountainous
are much colder than other lands at
the same latitude
Barriers to Wind
-The shape of the land can influence climate.
Mountain ranges may block even the strongest
winds.
-This can increase or decrease the amount of
precipitation that falls on the areas next to the
mountains.
-When moisture-filled winds (orange arrows) hit
the windward side, or wind-facing side, of
mountains, rain or snow falls.
-This is because as the air is forced to rise, it cools
and releases moisture.
-By the time the winds reach the opposite side of
the mountains, most or all of their moisture has
been lost.
As a result, the downwind, or leeward, side of
mountains is usually dry and cool.
More Resources!!
Weather VS. Climate
https://www.youtube.com/watch?v=VHgyOa7 Bill Nye video- Radiation, Conduction,
0Q7Y
Convection
Climate 101 with Bill Nye
https://www.youtube.com/watch?v=TDOjELim8w
https://www.youtube.com/watch?v=80w1mg4
Uh04
Song
Layers of the Atmosphere
https://www.youtube.com/watch?v=WaikvaA
w2nk
https://www.youtube.com/watch?v=yUEPGMnRq
Gs
www.happyscientist.com
www.sciencespot.net