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Solar Heating Exchange
Weather Patterns
Storm Disturbances
Uneven Solar Heating and
Atmospheric Circulation
What factors govern the global circulation of air?
 Uneven solar heating
 The Coriolis effect
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Uneven Solar Heating and Latitude
Earth as a whole is in thermal equilibrium, but different
latitudes are not. Moving masses of air and ocean currents
transport energy from locations with a surplus to those with
a deficit.
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Atmospheric Circulation
Atmospheric circulation is powered by sunlight. Since Earth is in thermal
equilibrium, what assumption can be made about the input and output of
heat on Earth?
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The Coriolis Effect
The Coriolis effect is the curving effect observed by a
person of a object moving into space, caused by the
revolving Earth.
As air warms, expands, and rises at the equator, it
moves toward the pole, but instead of traveling in a
straight path, the air is curved eastward.
In the Northern Hemisphere air turns to the right.
In the Southern Hemisphere air turns to the left.
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The Coriolis Effect
Air moves in cells, influenced by the Coriolis effect.
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Wind Bands
The Trade Winds are easterly winds located from
0 degrees to 30 degrees N/S.
The Prevailing Westerly winds are located from
30 to 60 degrees N/S.
The Polar Easterlies winds are located from
60 to 90 degrees N/S.
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The easterly trade winds of both hemispheres converge at an
area near the equator called the "Intertropical Convergence
Zone (ITCZ)", producing a narrow band of clouds &
thunderstorms that encircle portions of the globe.
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Pressure Zones
The Doldrums at 0 degree is a calm equatorial
area of Low pressure.
The Horse Latitudes are High pressure areas with
little surface wind which are located at
30 degrees N/S.
The Subpolar Zones are Low pressure areas
located below the north and south poles at
60 degrees N/S
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Wind and Pressure Patterns
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Sea Breezes
and
Land Breezes
Top: Sea breeze
Onshore movement of air
as inland air heats and
rises. ( in afternoon)
Bottom: Land breeze
Offshore movement of air
as marine air heats and
rises. ( in evening)
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STORM FORMATION
1.
2.
3.
4.
Low pressure zones ( high pressure moves to low)
Coriollis effect=cyclonic winds ( counterclockwise)
Begins at 5-30 degrees latitude
U.S. weather moves from Nw, Sw, Se then out Ne
TORNADOES
1.
2.
3.
4.
5.
From thunderstorms winds of 40-65 mph
Highest speeds 300 mph
Cause is steep pressure change
Form over, warm , dry areas
Eastern Great Plans most common area
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Nor’easter
When a storm low stops moving, its winds combine
with those of the neighboring high pressure system to
blow in one direction over a long period of time,
which creates huge waves. The duration of a
Nor'easter, & the number of high tides through which
it persists, can be the most significant measure of its
destructiveness.
Storms
Large tropical cyclones are called hurricanes. The
vertical dimension is exaggerated in this model of a
hurricane.
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Storms
The orange shaded areas and arrows designate
the location and movement of most hurricanes.
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A hurricane originating in the eastern tropical Atlantic, for
example, is driven westward by easterly trade winds.
Eventually, these storms turn northwestward around the
subtropical high and migrate into higher latitudes.
TROPICAL CYCLONE FORMATION
Stages of Development
Tropical Easterly Wave ( Tropical Disturbance)
Thunderstorms and light winds
Tropical Depression
Wind < 39 mph, pressure falls
or
Tropical Storm
Winds 39-73 mph
Hazardous seas
Hurricane
Winds 74 mph or more
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TURBULENCE
FEAR
IS IN
THE
AIR
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The End
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