Download ATMOSPHERE

ATMOSPHERE
Layers of the Atmosphere
Air pressure
Heat Transfer in the Atmosphere
Winds and Air Movement
Moisture in the Atmosphere
Composition of the Atmosphere
 What gases are found in
a normal volume of
breathable air?
 What is air?
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Nitrogen
Oxygen
Carbon Dioxide .03%
Argon .9%
Water Vapor 1-4%
Other trace gases
Layers of the Atmosphere
Troposphere
Stratosphere
Mesosphere
Thermosphere


Ionosphere
Exosphere
The Layers in Relation to the Earth
Uneven Heating of the Earth
Convection & Winds
How the Sun Strikes the Earth
 Cause of uneven Heating of
earth
– Earth’s Tilt
– A Sphere cannot receive
direct sunlight evenly
everywhere
 http://esminfo.prenhall.com/
science/geoanimations/anim
ations/01_EarthSun_E2.htm
l
Global Winds
•Winds that affect the entire globe
•Caused by the Rotation of the Earth
•Influenced by local
geology/landforms/elevations
Three Major Wind Belts in Each
Hemisphere
Easterlies
Westerlies
Tradewinds
Pressure Belts Associated With
Winds
Pressure Belts
 Air moves from high to low
pressure
 Cold air at the poles sinks
 Warm air at the equator
rises
 The Pressure belts are
divided up by these basic
movements of air
Local Winds
How local surroundings affect
breezes and winds
Local Winds
Caused by the unique conditions in each
location
Depends on landscape, elevation, latitude, and
nearness to bodies of water
Major Types:
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Land Breeze
Sea Breeze
Mountain Breeze
Valley Breeze
Thermals
Wind Shear
 Sea Breeze
Most closely
associated
with the daily
heating of the
earth and the
nightly cooling
of earth
 Land Breeze
Mountain Breeze Vs. Valley Breeze
Primarily a result of density – cold air sinks
and warm air rises
Day and Night affect this flow
Thermals
Thermals
Thermals are updrafts
of warm air that rise
from the ground
into the sky.
http://www.aerospaceweb.org/question/nature/
q0253.shtml
Wind Shear
 Wind shear is defined as
a change in wind speed
and/or direction within a
short distance. It can be
in either a horizontal or
vertical direction, or
both. This change
causes a shearing or
tearing effect, which
causes great concern for
pilots and airline
industries.
Air Masses
Characteristics
How we name them
The Weather they cause
Air Masses
 An air mass is a large
body of air with
generally uniform
temperature and
humidity. The area from
which an air mass
originates is called a
"source region."
Characteristics of Air Masses
Cold and Dry
Cold and Moist
Warm and Dry
Warm and Moist
Jet Stream
Naming Air Masses
 Continental arctic
 Continental polar
 Continental tropical
 Maritime arctic
 Maritime polar
 Maritime tropical
How Air Masses are formed and
named.
 Air Masses are named
for the area over
which they form.
Example: the air
over a tropical ocean
would be _______ &
____________.
Air Masses that affect North
America
 mP
* mT
 cP
* cT
 c = continental
 T = tropical
 P = Polar
 m= Maritime(ocean)
Typical Air Mass Movement
Air Mass Location Practice
Fronts
Fronts are the boundaries between air
masses of different temperature. If warm air
is moving toward cold air, it is a “warm
front”. If cold air is moving toward warm
air, then it is a “cold front
Types of Fronts
 Cold Front
 Warm Front
 Occluded Front
 Stationary Front
 Fronts are associated
with changes in
weather
Cold Front
Cold fronts occur when
heavy cold air displaces
lighter warm air,
pushing it upward.
Cumulus clouds form
and usually grow into
thunderstorms.
Temperatures drop
anywhere from 5
degrees to 15. Winds
become gusty and
erratic. Rain, snow,
sleet, and hail can
occur with a cold front.
Warm Front
 A warm front is defined as the
transition zone where a warm
air mass is replacing a cold air
mass. Warm fronts generally
move from southwest to
northeast and the air behind a
warm front is warmer and
more moist than the air ahead
of it. When a warm front
passes through, the air
becomes noticeably warmer
and more humid than it was
before
Occluded Front
 Occluded fronts occur when cold air is replacing cool air
or vice versa at the surface, with warm air above. A cold
occlusion occurs when cold air shoves its way under
cool air at the surface. Warm air aloft is usually to the
west of the surface front. A warm occlusion occurs when
cool air rises over cold air. The warm-cold air boundary
is often east of the surface front. Both types of fronts are
usually associated with rain or snow and cumulus
clouds. Temperature fluctuations are small and winds
are gentle
Stationary Front
 Stationary fronts occur
when neither warm nor
cold air advances. The
two air masses reach a
stalemate. These type
of conditions can last
for days, producing
nothing but Altocumulus
clouds. Temperatures
remain stagnant and
winds are gentle to nil.
Cyclone/Anti Cyclone
Coriolis Effect
 http://www.classzone.
com/books/earth_scien
ce/terc/content/visuali
zations/es1904/es1904
page01.cfm?chapter_n
o=visualization