Download due to uneven heating pressure differences Earth`s Winds

WINDS
Responsible for
triggering the initial
movement of air.
CORIOLIS EFFECT
SHIFT IN
WIND
DIRECTION
DUE TO
EARTH’S
ROTATION
What happens if
pressure is the same?
No wind!
Earth’s Winds- due
to uneven heating 
pressure differences
Earth’s Winds- due
to uneven heating 
pressure differences
Local
Winds
Land
breeze
Sea
breeze
LOCAL WINDS
Uneven heating
of land vs water
SEA
BREEZE
LAND
BREEZE
Earth’s Winds- due to
uneven heating 
pressure differences
Local
Winds
Seasonal Windsover bigger region
(ex-SE Asia)
Land
breeze
Sea
breeze
monsoon
MONSOONS
SEASONAL WINDS
Similar to land and sea breeze bit occur over a wider area
Philippines
Northeast Monsoon
(cold and wet)
Southwest Monsoon
(dry)
Earth’s Winds- due to
uneven heating 
pressure differences
Global/Planetary
Winds
Local
Winds
Seasonal Windsover bigger region
(ex-SE Asia)
Land
breeze
Sea
breeze
monsoon
GLOBAL WINDS
UNEQUAL HEATING
equater vs. poles
results in
GLOBAL PATTERN OF AIR
CIRCULATION
http://www.phschool.com/atschool/phsciexp
ctive_art/global_winds/index.html
Jet Stream
Earth’s Winds- due
to uneven heating 
pressure differences
Up In Atmosphere
Global/Planetary
Winds
Local
Winds
Seasonal Windsover bigger region
(ex-SE Asia)
Land
breeze
Sea
breeze
monsoon
Trade
Winds
On Surface
Polar
Prevailing
Easterlies
Westerlies
TRADE WINDS
ON SURFACE:
AIR MOVING
BACK TO THE
EQUATOR
FORMING A
BELT OF
WARM,
STEADY
WINDS
PREVAILING WESTERLIES
ON SURFACE
40-60 degrees
Latitude (West to
East)
Strong
Winds
POLAR EASTERLIES
ON SURFACE
COLD BUT WEAK
WINDS
EAST TO WEST
JET STREAMS
“rivers of air"
IN ATMOSPHERE
(ABOVE 12 KMS)
180-350 Km/Hr
(speed)
Jet Stream
Earth’s Winds- due
to uneven heating 
pressure differences
Up In Atmosphere
Global/Planetary
Winds
Local
Winds
Seasonal
Winds- over
bigger region
(ex-SE Asia)
Land
breeze
Sea
breeze
Trade
Winds
On Surface
Polar
Prevailing
Easterlies
Westerlies
NO
Winds
monsoon
Doldrums
Horse
Latitudes
DOLDRUMS
ON
SURFACE
CALM/ NO
WINDS AT
EQUATOR (0
degrees
latitude)
HORSE LATITUDES
ON SURFACE
30 degrees North
and South of
Equator
Warm air cools
and sink; clear
skies; winds are
calm
http://www.phschool.com/atschool/phsciexp
ctive_art/global_winds/index.html
CORIOLIS EFFECT
SHIFT IN
WIND
DIRECTION
DUE TO
EARTH’S
ROTATION
As air moves from high to low pressure:
in north, air deflected right/counterclockwise
in the south, air is deflected left/clockwise
hurricanes/typhoons and tornadoes
spin COUNTER-CLOCKWISE
in NORTH
Flushing Toilets on the Equator
Myth or Real:
Toilets flushed in the northern hemisphere
apparently spin to the right, in the
southern hemisphere
myththe water spins left - this is supposedly caused by the Coriolis
effect. And on the equator? It's a straight
shot down.
BREAK TIME
• One big/important idea or fact
• Stand up
• Share with 3 people
So how do we get differences in
pressure?
All factors making
Low density & low pressure
1) temp: Warm air is less dense than cool air.
REMEMBER THE OPPOSITE IS ALSO TRUE
UNEQUAL HEATING OF AIR
DIFFERENCES IN DENSITY
DIFFERENCE IN AIR PRESSURE
EX) HOT temp (LESS dense)=>LOW P
COLD temp (MORE dense)=>HIGH P
TEMPERATURE AND AIR PRESSURE
LESS AIR
PRESSURE
HEAT
Air molecules
move faster
and expand
Air RISES
less dense
All factors making
Low density  low pressure
1) temp: Warm air is less dense than cool air.
2) humidity: Moist air is less dense than dry
air.
REMEMBER THE OPPOSITE IS ALSO TRUE
More water vapor means
less air molecules
Less dense = LOW AIR PRESSURE
DRY AIR  more dense = HIGH AIR
PRESSURE
All factors making
Low density  low pressure
1) temp: Warm air is less dense than cool air.
2) humidity: Moist airis less dense than dry air.
3) elevation: Air at high altitudes
(mountains) is less dense than air at lower altitudes.
REMEMBER THE OPPOSITE IS ALSO TRUE
Air at high altitudes is
more spread out = less dense
than air at lower altitudes.
Measuring Air Pressure
Air Pressure
is measured by
an instrument
called
Barometer
2 Main Types of
Barometer
Mercury Barometer
Aneroid
(spring)
Air pressure
increases,
column of
mercury rises

VIDEO: Why use mercury?
Air pressure
decreases,
column of
mercury drops

Video (minute 2): http://www.youtube.com/watch?v=gGBMCqBoSE&feature=related
Break time
• Think of one fact you learned from the
video or what you found interesting
• Stand up
• Form groups based on the same idea
CLOUDS
TYPES OF
CLOUDS
CLOUD FORMATION
1) WATER VAPOR (gas) rising
(need heat to cause evaporation)
2) CONDENSATION NUCLEI
(smoke, dust, pollution)
3)LOW TEMPERATURE for
condensation (liquid) to occur
MOISTURE
CONDENSES ON
SMALL PARTICLES
OF DUST/ SOLIDS IN
THE AIR
CONDENSATION
WATER VAPOR
CHANGES
INTO LIQUID
(need cold temp)
DEW POINT
TEMPERATURE AT WHICH
water vapor CONDENSES
Source: http://www.vivoscuola.it/US/RSIGPP3202/umidita/lezioni/form.htm
Air Pressure & Weather
TEMPERATURE AND AIR PRESSURE
LESS AIR
PRESSURE
HEAT
What happens
when air rises?
Air molecules
move faster
and expand
Air RISES
less dense
Low pressure generally
means cloudy, rainy
weather
Warm air
rises, clouds
form
High pressure generally
means fair weather
Layer of Air
Warm,
=No
clouds
moist air
cannot rise
Weather map
High Pressure System: Indicates
clear, calm conditions with reduced
chance of precipitation.
DRY and COLDER air
Low pressure system:
Increased cloudiness, winds,
higher temperatures, and
chance of precipitation.
Frost Formation
• Cold temperature causes water vapor
(gas) to instantly freeze (solid)
• Skips liquid phase (never wet)
• Salt helped to make colder
When condensed water
gathers into drops that
are heavy enough,
precipitation occurs
Source: http://www.vivoscuola.it/US/RSIGPP3202/umidita/lezioni/form.htm
Cloud
droplets
PRECIPITATION
Ice
Snow
Hurricanes/Typhoons/Cyclones
&
Tornadoes
Hurricanes/typhoons/cycloneswhat’s in a name?
LOCATION, LOCATION, LOCATION
http://spaceplace.nasa.gov/hurricanes/
HOW?
hurricanes/typhoons and tornadoes
spin COUNTER-CLOCKWISE
in NORTH
H
H
H
H
http://edition.cnn
.com/2011/US/0
4/28/severe.wea
ther/index.html?
hpt=T2
http://edition.cn
n.com/2011/US
/04/27/tornado.
outbreak/index.
html?hpt=T1
Experts: Severe
weather across
South could set
tornado record
Including yesterday's storm,
there have been a whopping
800 reports of tornadoes in
April, easily surpassing April
2003's all-time record of 543
twisters.
http://www.nytimes.com/interactive/20
11/04/28/us/map-of-the-tornadoesacross-the-south.html
http://news.yahoo.com/s/yblog_thelookout/
20110428/ts_yblog_thelookout/watchtuscaloosas-terrifying-tornado
Yahoo video clips
Tornadoes
Song:
http://www.youtube.
com/watch?v=iOw6
ONcKk4g