Weather and Climate

1
Weather and Climate

• Chapter C3

2
Where Weather Occurs

• Almost all weather occurs in the ________ layer
  of air, or atmosphere that surrounds Earth. This
  layer is called the ______________
• The atmosphere stretches about _______ miles from
  the Earths surface to outer space
• Very little weather occurs above the
  _____________
• There is little water in the _____________, the
  next higher layer, so few ________ form there
• The stratosphere contains the ________ layer
  which protects life on Earth by _________ some of
  the suns harmful rays
• From the stratosphere to the edge of space, there
  is no ________ and too little air for any
  __________ to occur

3
Measuring Atmospheric Conditions

• Weather changes because the _________ is
  constantly changing
• As air _________, its weight, or air pressure,
  lessens
• Warm air can also hold more ______, or can have
  more _________, than cold air
• Humidity in the air is measured using a
  ______________
• A ____________ measures air temperature
• Air pressure is the __________ of the atmosphere
  and is measured using a ___________
• A ________ __________ measures the amount of
  precipitation
• A ________ ________ measures the direction from
  which the wind is blowing and an _________
  measures wind speed
• Measuring atmospheric conditions helps to
  ___________ what upcoming weather will be

4
Air Pressure

• The atmosphere pushes on you all the time, and
  this weight is ______ __________
• Warm air weighs _______ than cold air and a mass
  of cold air is called a _______-_________ area,
  weighing more that 76 cm of ___________
• A mass of warm air, called a ______-___________
  area weighs _______ than 76 cm of mercury
• Weather changes because areas of high- and
  low-pressure areas ________
• In the winter, areas of high pressure often move
  from ________ in the north bringing ______,
  ________ weather conditions
• In the summer, areas of _______ pressure often
  move from the south bringing _______, _______
  weather conditions
• ___________ readings indicate changes that may be
  coming--when barometer rises, weather will become
  _________ and when barometer is falling,
  _________ weather may be coming

5
Water in the Air (1)

• In addition to temperature and air pressure,
  ___________, or the amount of water in the air,
  can affect weather conditions
• Earths ________ are the biggest source of water
  and as the sun heats them the water changes into
  an invisible _______ called water ________
• The process of liquid water changing into water
  vapor is called ____________
• High in the atmosphere, where air is _________,
  water vapor turns back into liquid drops of
  water, forming __________
• When cloud drops come together, __________
  returns the water to the Earths surface as
  ____________ in the form of rain, hail, sleet or
  snow
• Water vapor __________ into cloud drops
• When water ___________ from soil, plants, lakes,
  and rivers, solids and any pollutants are left
  behind and when water evaporates from the
  __________, salt is left behind

6
Water in the Air (2)

• When the surface of the Earth cools quickly,
  water vapor may condense to form a ________ near
  the ground, called ______
• Clouds form when water vapor ___________ onto
  dust and other tiny particles as it cools and
  rises or when water vapor condenses as a result
  of moving from a _______ place to a ___________
• The three basic names of clouds are _________
  (the highest type which look thin and wispy),
  ___________ (form when large bubbles of warm air
  rise rapidly and look puffy), and __________
  (form as a mass of warm air is slowly pushed over
  a mass of colder air and often produce rain or
  snow)

7
Uneven Heating

• Roughly _____ of suns energy is absorbed by
  Earths surface _____ is absorbed and reflected
  by clouds and ____ is absorbed by air
• Soil heats up ________ than water and therefore
  land absorbs the suns energy more quickly and
  heats up faster than bodies of water
• ________ also releases heat and cools off faster
  when the sun goes down than bodies of water do

8
Local Winds

• Because Earths surface is heated unevenly, the
  air above it is in constant ________
• _________ air is heavier than _______ air, so it
  sinks, forcing lighter, warm air to rise
• At the surface, two places can have differences
  in temperatures and, therefore, differences in
  _____ __________ and this causes air to move
  from the _________ pressure to the area of
  _______ pressure
• This horizontal movement of air is called
  _________
• Local winds depend on local changes in
  ____________
• Describe what is happening in diagrams on page
  C73

9
Prevailing Winds

• Prevailing winds are _________ winds that blow
  constantly from the same ___________
• Prevailing winds are caused by _______ heating of
  large parts of Earths atmosphere and by Earths
  __________
• Cold, _______ polar air flows toward the
  _________, forcing an upward movement of the
  warmed air at the equator in the direction of the
  _________
• The global winds that blow over most of the
  Unites States are prevailing __________ and curve
  ________
• Weather conditions on the _______ Coast today
  often move to the middle of the country tomorrow
  and from there to the _______ Coast the next day

10
Climate

• The repeated weather conditions that occur year
  after year are known as ____________, and is the
  average of all weather conditions through all
  seasons over a period of time
• _________ and _________ are the major factors
  that determine climate
• A ____________ is the climate of a very small
  area and may reflect differences in precipitation
  or temperature

11
Climate and Latitude

• In the United States, there is the cold,
  _________ climate of northern Alaska and the hot,
  _________ climate of Hawaii
• Most of the country has more moderate, or
  ________, climates
• Along the east coast of the United States
  temperatures vary according to the areas
  __________, or the distance a place is from the
  equator
• Most areas near the ________ have tropical
  climates because the sun is directly overhead
  nearly all year long
• In __________ climates the sun is directly
  overhead for only part of the year and they often
  have warm summers and cod winters
• Near the _________ the sun is never directly
  overhead and the decreased heating of the Earths
  surface at ___________from the equator results in
  cold, polar climates
• In addition to latitude, ______________ causes
  differences among temperate climates

12
World Climates

• Anything that affects ________ or __________
  affects climate
• In the United States, prevailing ____________
  help to moderate the hot summer climate by
  pushing _______ air masses across the country
• Ocean _________ can affect climate, too,
  especially along the coast
• Another factor that can affect climate is the
  _________ of the land to include landforms
• The five major climate zones of Earth are
  ________, ___________, _____________,
  _____________, and ____________

13
Climate Changes

• Scientists have determined through research that
  Earths climate is slowly _________
• During the most recent Ice Age, __________
  covered 30 of Earths surface
• Changes in Earths temperature might be caused by
  a change in the size of shape of Earths ________
  or a change in the _______ of Earths axis (read
  caption for graph on page C81)
• Earths temperature has _________ and _________
  over time
• The ___ ________ is an example of a short-term
  change in climate and affect areas around the
  ________ ocean

14
Humans Affect Climate

• _________ are warmer than country areas or
  surrounding areas due to the heat held by
  buildings, roads, and sidewalks and the blocking
  by large buildings of _______ to move warm air
  out
• Warm air also results from an effect of the
  burning of ________ _______ such as gasoline
• Carbon dioxide in the atmosphere absorbs some of
  the heat given off by Earth and this is known as
  the ___________ __________
• Earth needs ________ ________ to keep Earth from
  becoming too cold to sustain life, but too much
  can lead to climate changes
• Scientists hypothesize that excess carbon dioxide
  will lead to _______ _________
• If Earths average temperature rises just a few
  more degrees, the polar icecaps will begin to
  melt and the increased sea levels could lead to
  ______________ in many coastal cities