Climates of the Earth
Chapter 3
Seasons
• Solstice: Marks the
longest or shortest day
of the year.
• Winter solstice:
December
• Summer Solstice: June
Seasons
•Equinox: Even days
of sunlight and
darkness.
•Fall: September
•Spring: March
Weather
• The condition of the
atmosphere at a
particular place and
time.
Climate
•Weather in a
particular location
over a long period of
time.
Precipitation: falling water droplets
in the form of rain, sleet, or snow.
• Convectional: In hot
climates morning
sunshine heats warm
moist air. Clouds form in
the afternoon and rain
falls.
Orographic
• Associated with mountain
areas. Storms drop more rain
on the windward side of a
mountain and less on the
leeward side, creating a rain
shadow.
Frontal
• Mid-latitude frontal
storms-cold dense air
masses that push lighter
warm air upwards,
causing precipitation to
form.
Rain Shadow
• A dry area that receives
very little precipitation
from the descending dry
air on the leeward side
of a mountain range.
Weather Extremes
•Blizzards: a heavy
snowstorm with high
winds and reduced
visibility.
Droughts
• A long period of time with
little or no rain that can lead
to crop failures, reduced
water levels, and possible
dust storms.
Hurricanes
 Form in late summer to early
Fall over tropical waters off the
coast of Africa.
 Also form off of the western
coast of Mexico.
 Normally track towards the
eastern United States.
Typhoons
Form in the Pacific
Ocean between the
International Date Line
and the coasts of Asia
or Australia.
Cyclones
Form in the Indian
Ocean and normally
track towards South
Asia.
Characteristics of all three storms:
• High winds, thunderstorms, heavy
rain, and storm surges.
• Large air mass storms.
• Normally born in tropical latitudes
and move towards mid-latitudes,
feeding off of the ocean’s energy.
(moisture and heat)
• 74 mph minimum
Tornado
• Spawned by severe thunderstorms
across the central U.S. when cold
and warm air masses collide.
• When a huge storm, towering in the
atmosphere is sheared at the top
by winds it can create a spinning
motion in the system. A funnel
shaped cloud drops from the main
storm cloud and destructive winds
in excess of 100 mph can be
generated.
• The Fujita scale measures the
destructive potential of these
storms.
• The most violent of all storms.
F0 Gale tornado 40-72 mph
Some damage to chimneys;
breaks branches off trees;
pushes over shallow-rooted
trees; damages sign boards.
F1 Moderate tornado 73-112 mph
• The lower limit is the beginning of
hurricane wind speed; peels
surface off roofs; mobile homes
pushed off foundations or
overturned; moving autos pushed
off the roads; attached garages
may be destroyed.
F2 Significant tornado 113-157 mph
• Considerable damage. Roofs torn
off frame houses; mobile homes
demolished; boxcars pushed over;
large trees snapped or uprooted;
light object missiles generated.
F3 Severe tornado 158-206 mph
• Roof and some walls torn off
well constructed houses;
trains overturned; most trees
in forest uprooted
F4 Devastating tornado 207-260 mph
• Well-constructed houses
leveled; structures with weak
foundations blown off some
distance; cars thrown and large
missiles generated
F5 Incredible tornado 261-318 mph
• Strong frame houses lifted off
foundations and carried
considerable distances to
disintegrate; automobile sized
missiles fly through the air in
excess of 100 meters; trees
debarked; steel reinforced concrete
structures badly damaged.
Tornado Season
• February: Southern Gulf states-peaking
in April and May.
• June July and August-Tornado Alley:
Oklahoma, Kansas, et. al.
Monsoons
• Seasonal Shifts in wind
patterns affecting parts of
South Asia and SE Asia.
• From November to April the
prevailing winds blow from
the land, therefore they are
dry.
• From May to October the prevailing
winds blow from the ocean,
therefore they are wet.
• During the wet season the rains are
persistent and often torrential,
leading to flooding and other
related problems, but this is a boon
to the rice farmers.
Factors Affecting Climate
• Wind currents help to distribute the
world’s heat energy through
convection.
• Convection: the transfer of heat in the
atmosphere by upward motion of the
air.
• Which wind currents affect our
climate? westerly's
• Ocean Currents: Hot or Cold?
Zones of Latitude:
• Low or Tropical Latitudes
are found on either side of
the equator. They extend to
the Tropic of Cancer in the
North to the Tropic of
Capricorn in the South.
Lands here are hot all year.
Zones of Latitude:
•
High or Polar Latitudes are
found encircling the North and
South Pole. They are cold all
year and the boundaries are
defined by the Arctic and
Antarctic circles.
Zones of Latitude:
• The Middle or Temperate
Latitudes are located within
the Tropic and Polar
regions. They generally
have warm summers and
cold winters
• Elevation: As elevation
increases temperature
decreases
• Topography: See
Orographic Effect.
Changes in Climate
• El Nino: See the skill builder on page
57.
• An abnormal winter warming of the
mid-latitude waters in the Pacific
Ocean can cause extreme imbalances
in weather patterns.
• For example: Places that are normally
wet suffer sever drought and places
that are normally dry suffer heavy rain
and flooding.
Global Warming
• This is the theory that the
temperature of the earth is
increasing at an alarming
rate. This may increase the
level of the oceans, causing
coastal flooding and lead to
greater tropical storms.
Greenhouse Effect
• This may be one of the
factors causing global
warming. Co2 pollution in the
atmosphere is trapping the
sun’s energy and causing the
polar ice caps to melt.
Climate Definitions
• Tropical: Yearly average
temperature of 80 degrees
and daily rainfall. Many rain
forests are located in this
area surrounded by tropical
grasslands.
Arid/Semi-Arid
• Dry or nearly dry climates
receive little rainfall.
Scrub grasses and
bushes predominate.
Deserts:
• Next to no rainfall.
• They can be extremely hot
during the day and very cold at
night.
• Cold deserts can be found in
the mid-latitudes in mountain
rain shadows.
Mediterranean:
• Named for the climate around
the Mediterranean Sea, but
can also be found in
Southern California.
• Warm, dry Summers
• Cool, rainy Winters
Marine:
• Marine means ocean and that
is what affects these climates
the most.
• Cool and rainy year round
• British Isles
• Seattle, Washington
Humid Subtropical
• Found on the east coast of
continents.
• Long, hot, and humid
Summers.
• Winters are relatively mild.
• Subject to hurricanes.
Humid Continental
• Humid indicates that there is
sufficient rainfall, but
continental indicates that this
climate is more affected by the
land and therefore cooler.
• Winters are longer and colder.
Subarctic:
• Evergreen forests called
Taiga cover most of the
region.
• Winters are very cold.
• Summers are short and cool.
Tundra:
• Flat treeless lands that form
a ring around the Arctic
Circle.
• The land has permafrost: the
subsoil is permanently
frozen.
Permafrost:
• See previous slide.
Ice Cap
• Snow, ice and permanently
freezing temperatures.
• Found at the poles and high
in Mountain ranges.
• Think Alps or Mt. Everest
Highlands
• A Highlands climate can
vary with altitude, latitude,
and continental location.
• Ex: Andes Mountains in
South America.
Soil and Vegetation
•Ecosystem: an
interdependent
community of plants
and animals.
Biome
•Classifications of
forest, tundra,
grassland, etc.
Forestlands are characterized by
the type of trees they support.
• Rain Forest: found in tropical
zones and covered with a heavy
concentration of broadleaf trees.
• The treetops are so thick that they
create a roof-like canopy over the
forest.
• This creates an environment below
for shade-loving plants.
Deciduous Trees
• Broadleaf trees such as
Maple, Oak, etc., that shed
their leaves in the Winter.
Coniferous Trees
• Cone-bearing, needle-leaf trees
that stay green year round.
• Ideally suited for colder
climates.
• Think Christmas trees.
Grasslands are grassy, treeless
plains.
• Savanna: A tropical
grassland region.
• Think lions running down
zebras in Africa.
Steppe:
• These temperate grasslands
are sometimes called
prairies.
• The Pampas in Argentina.
• The Great Plains in the U.S.
THE END