Transcript Weather and Climate

Weather and Climate
Chapter C3
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
Earth’s 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 sun’s
harmful rays
 From the stratosphere to the edge of space, there is no
________ and too little air for any __________ to occur
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
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
Water in the Air (#1)
 In addition to temperature and air pressure, ___________, or the
amount of water in the air, can affect weather conditions
 Earth’s ________ 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
Earth’s 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
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)
Uneven Heating
 Roughly _____% of sun’s energy is absorbed by
Earth’s surface; _____% is absorbed and reflected by
clouds; and ____% is absorbed by air
 Soil heats up ________ than water and therefore
land absorbs the sun’s 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
Local Winds
 Because Earth’s 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
Prevailing Winds
 Prevailing winds are _________ winds that blow constantly from
the same ___________
 Prevailing winds are caused by _______ heating of large parts
of Earth’s atmosphere and by Earth’s __________
 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
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
Climate and Latitude
 In the United States, there is the cold, _________ climate of
northern Alaska and the hot, _________ climate of Hawai’i
 Most of the country has more moderate, or ________, climates
 Along the east coast of the United States temperatures vary
according to the area’s __________, 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 Earth’s surface at ___________from
the equator results in cold, polar climates
 In addition to latitude, ______________ causes differences
among temperate climates
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
____________
Climate Changes
 Scientists have determined through research that Earth’s
climate is slowly _________
 During the most recent Ice Age, __________ covered
30% of Earth’s surface
 Changes in Earth’s temperature might be caused by a
change in the size of shape of Earth’s ________ or a
change in the _______ of Earth’s axis (read caption for
graph on page C81)
 Earth’s temperature has _________ and _________ over
time
 The ___ ________ is an example of a short-term change
in climate and affect areas around the ________ ocean
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 Earth’s 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