Transcript Standard EPS Shell Presentation

Integrated Science
Unit 9, Chapter 27
Unit Nine: Energy in the Earth System
Chapter 27 Weather and Climate
27.1
Earth's Heating and Cooling
27.2 Global Winds and Currents
27.3 Weather Patterns
27.4 Storms
27.5 Weather and Climate
Chapter 27 Learning Goals
Learn how Earth’s rotation, Earth’s axial tilt, and distance
from the equator cause variations in the heating and
cooling of Earth.
 Learn how the heating of Earth’s surface and atmosphere
by the sun causes convection cycles in the atmosphere
and oceans, producing winds and ocean currents.
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Learn about tools meteorologists use to predict weather,
and how to read a weather map.
 Make and test your own weather instrument.
 Model a Doppler radar system.
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Learn about the physical features that interact to form
the climate of each of six important land biomes.
Chapter 27 Vocabulary Terms
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air mass
El Niño-Southern Oscillation
biome
cold front
Coriolis effect
cumuliform cloud
desert
grassland
gyres
isobars
jet stream
latitude
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longitude
prevailing westerlies
polar easterlies
temperate forest
stratiform cloud
stratocumulus cloud
taiga
temperature inversion
trade winds
tropical rainforest
tundra
warm front
27.1 Variations in Earth's Heating
and Cooling
Key Question:
 What
causes
seasons?
*Read text section 27.1 AFTER Investigation 27.1
27.1 Heating and Cooling Earth
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Satellite data is used to
map patterns of heating
and cooling.
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The National Oceanic and
Atmospheric
Administration (or NOAA)
uses infrared photography
to map how much heat is
reflected or emitted from
different areas of Earth
each day.
27.1 Latitude
 Latitude
lines measure
distance from the equator.
 These
lines run parallel to the
equator and are labeled in
degrees north or degrees south.
27.1 Longitude
 Longitude
lines run vertically from the north
pole to the south pole.
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The line that runs through
Greenwich, England, is labeled 0
degrees longitude and is called the
prime meridian.
Lines east of the prime meridian are
numbered from 1 to 179 degrees
east, while lines west of the prime
meridian are numbered from 1 to 179
degrees west.
The 0- and 180-degree lines are not
labeled east or west.
27.1 Temperature and Latitude
 Earth’s
temperature varies
with latitude.
 At
higher latitudes, solar
radiation is less intense.
 The
same thing happens to
the sun’s energy when it
reaches the south pole at
an angle.
27.1 Temperature and Rotation
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As Earth rotates, the portion of the globe facing the sun
warms as it absorbs more solar radiation than it emits.
 Earth constantly emits some of the absorbed energy as
infrared radiation.
 This emission of heat cools the dark side of the planet.
27.2 Global Winds and Ocean Currents
 Thermals
are small convection currents in the
atmosphere.
 While
thermals form on a
local level, there are also
giant convection currents
in the atmosphere.
 These
form as a result of
the temperature difference
between the equator and
the poles.
27.2 Coriolis Effect
 Bending
of air currents is
called the Coriolis effect,
after the French engineer
mathematician Gaspard
Gustave de Coriolis (17921843), who first described
the phenomenon in 1835.
27.2 Global Winds
 There
are three important
global surface wind
patterns in each
hemisphere:
— trade winds
— polar easterlies
— prevailing westerlies
27.2 Ocean Currents
 Global
wind patterns and Earth’s rotation cause
surface ocean currents to move in large circular
patterns called gyres.
27.2 Global Winds and Ocean Currents
Key Question:
 How
do temperature and salinity cause
ocean layering?
*Read text section 27.2 BEFORE Investigation 27.2
27.3 Weather Patterns
 Three
important factors
that shape the weather in a
given region are:
— temperature
— pressure
— water
A
sling psychrometer can
measure water in the air.
27.3 Phase changes of water
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Water in the atmosphere exists in all
three states of matter.
 High in the troposphere, there are
ice crystals.
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Tiny water droplets, much too small
to see, are suspended throughout
the troposphere virtually all the time.
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Other water molecules in the
atmosphere are truly in the gas
state, separate from all other
molecules.
27.3 Cloud formation
 Different
conditions
cause different clouds.
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Cumuliform clouds form
when convection causes
rising pockets of air in the
atmosphere.
 Cumuliform clouds include:
— cirrocumulus
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—
altocumulus
cumulus
cumulonimbus
27.3 Cloud formation
 Different
conditions
cause different clouds.
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Stratiform clouds form when
a large mass of stable air
gradually rises, expands, and
cools.
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Stratiform clouds include:
— cirrostratus
— altostratus
— nimbostratus
27.3 Cloud formation
 Sometimes
a cloud formation combines aspects
of both cumuliform and stratiform clouds.
 We
call these clouds stratocumulus clouds.
27.3 Cloud formation
 Cirrus
clouds are thin lines of ice crystals high
in the sky, above 6,000 meters.
 They
are just a thin streak of white across a
blue sky.
27.3 Precipitation
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A raindrop begins to form when water
molecules condense on a speck of dust.
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At first it is round, but when it is large
enough that it begins to fall, air resistance
causes the underside of the drop to flatten,
so that it looks more like a hamburger bun.
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As it grows larger, it looks more like an
upside down bowl with a thick rim.
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If it hasn’t hit the ground by this point, it
will break up into smaller droplets and the
process repeats itself.
27.3 Air masses and fronts
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An air mass is a large body of air with consistent
temperature and moisture characteristics throughout.
 Changing atmospheric conditions and global wind
currents eventually cause these air masses to move.
27.3 Low and high pressure areas
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When a cold front moves
into a region and warm air is
forced upward, an area of
low pressure is created near
Earth’s surface at the
boundary between the two
air masses.
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A center of high pressure tends to be found where a
stable cold air mass has settled in a region.
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Isobars show areas with the same atmospheric pressure
on map.
27.3 Weather Patterns
Key Question:
How can we measure
water content in the
atmosphere?
*Read text section
27.3 BEFORE
Investigation 27.3
27.4 Storms
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Thunderstorms arise when
air near the ground is
strongly warmed and rises
high into the troposphere.
 As the air rises, it cools
and condenses, forming a
towering cumulonimbus
cloud.
 Eventually some of the
cloud droplets become
large enough to fall as
rain.
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a storm cell
27.4 Hurricanes
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Several conditions must be
present for a rotating system to
become a hurricane:
— wind speeds of at least 74
miles an hour.
— warm ocean water must be
at least 46 meters deep.
— the air must be warm and
moist to a point at least
5,500 meters above sea
level.
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a tropical cyclone
27.4 Tornadoes
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A tornado, like a hurricane, is a
system of rotating winds around
a low pressure center.
 An average tornado is tiny,
compared with the average
diameter of a hurricane.
 However, the wind speeds of a
tornado are much greater than
those of a hurricane.
 A tornado’s wind speed can
reach 400 kilometers per hour.
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a tornado
27.4 Storms
Key Question:
 How
does
Doppler radar
work?
*Read text section 27.4 BEFORE Investigation 27.4
27.5 Weather and Climate
 Climate
is defined as
the long-term average
of a region’s weather.
 Climate
depends on
many factors:
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latitude
precipitation
elevation
topography
distance from large bodies
of water
27.5 Weather and Climate
 Scientists
divide the planet into climate regions
called biomes.
 An
example of a biome is desert.
27.5 Biomes
Key Question:
 How
do zoos model climates?
*Read text section 27.5 BEFORE Investigation 27.5