Download Location and Climate

How is wind created?
The uneven heating of the Earth's surface by the sun
creates wind.
What causes the wind to blow?
As the sun warms the Earth's surface, the atmosphere warms too. Some
parts of the Earth receive direct rays from the sun all year and are
always warm. Other places receive indirect rays, so the climate is
colder. Warm air, which weighs less than cold air, rises. Then cool air
moves in and replaces the rising warm air. This movement of air is what
makes the wind blow.
Global Winds vs. Local Winds
· movement of air across large
distances.
· they flow high up in Earth's
atmosphere.
· they move in predictable
patterns and do not change
much.
· move across smaller distances.
· move closer to the Earth's surface.
· respond to changes in air
pressure.
· they are less predictable, because
they change with the weather.
Heating & Cooling Causes
Global Winds
· The sun heats the Earth more at the Equator and less at the
poles.
· Air moves across the Earth to distribute this heat more evenly.
· This creates global winds that flow between the Equator and
the poles.
· These winds change direction at different latitudes due to the
rotation of the Earth.
Global Wind #1: Polar Easterlies
Look at the words 'Polar' and
'Easterlies', where do you think
these winds are coming from?
· Cold winds that begin in the east
and blow toward the west.
· These winds begin and blow away
from the poles (North & South
Poles)
· Why do these winds blow away
from the poles? (hint: Think about
what cold air wants to do)
Global Wind #2: Prevailing
Westerlies
Look at the word Westerlies, where
do you think these winds are
coming from?
· Move from west to east.
· These winds affect our weather by:·
Moving systems (High Pressure and
Low Pressure) from west to east
across the United States.
· Moving fronts (Warm, Cold,
Stationary, Occluded) from west to
east.
Global Wind #3: Trade
Winds
· Wind moving towards the Equator
· Blows from East to West.
· Warm, steady breezes that blow
almost continuously.
· Called Trade Winds due to their
ability to move trading ships across
the ocean.
Jet Streams
• A jet stream is a band of fast-moving wind located 5
– 7 miles above earth’s surface that flows from west
to east.
• Where a jet stream flows over North America, it
greatly affects the weather.
• Jet streams affect the paths of storms and movement
of high and low pressure systems.
Types of Jet Streams
• Jet streams do not follow regular paths around Earth.
Instead, they dip, bend, and change position.
• When the polar jet stream dips south, it lets cold air
from Canada flow down into the USA (this is the
main one that affects our weather).
• When the subtropical jet stream bends north, it lets
warm air flow in from the South.
Images
Think, Pair, Share
• What is the name of the global wind that moves weather
systems across the USA?
• What is a jet stream?
• What jet stream affects the USA the most?
• How does the jet stream affect temperatures and movement of
weather systems?
Local Breezes
• Water takes a long time to heat and cool.
• Land heats and cools rapidly.
• Differences in the rate of cooling and heating
between land and water create differences in air
pressure.
• Remember, air always wants to go from high pressure
to low pressure.
Sea Breezes
• During the day as warm air over the land rises (low pressure),
cool air from over the ocean rushes in to takes its place (high
pressure); this is called a sea breeze.
• Remember, air always wants to go from high pressure to low
pressure.
Land Breezes
• During the night, the air temperatures switch; the warm air is
now above the ocean since it takes longer for water to cool
down, and the cool air is above the land since the land cools
quicker.
• The warm air over the ocean rises (low pressure) and the cool
air from the land rushes in to take its place (high pressure); this
is called a land breeze.
• Remember, air wants to go from high pressure to low pressure.
Monsoons
• A monsoon is a sea breeze that occurs on a larger
scale and for a longer time.
• A monsoon usually forms during the summer when
the sun heats a large area of land.
• This warm air rises and cool air from the ocean
rushes in to take its place.
• As the moist air from the ocean moves over the land,
it produces heavy rain, often times for months.
• https://www.youtube.com/watch?v=uFilBJsu224
Hurricanes
• https://www.youtube.com/watch?v=4f45jA5U
xB0
The Gulf Stream
• The Gulf Stream is a powerful Atlantic Ocean current that
circulates warm water up the East Coast of the USA.
• The Gulf Stream impacts local weather by helping to keep
temperatures along coastlines (like North Carolina’s) mild as it
brings warm moist air to those areas.
Current: the
movement of
the surface
layer of water
in response to
the force of
winds above it.
Video Link:
https://w
ww.youtub
e.com/wat
ch?v=rR5T
FWNLtOc
El Nino
*El Nino is a weather phenomenon where there is an
unusual warming of the surface water in the eastern
Pacific Ocean near the Equator.
*This occurs sometime in December, every 3-5 years,
lasting 9-12 months.
*SST = Sea
Surface
Temperatures.
Effects of El Nino
*The jet stream is pushed south during this time and this affects the
track of storms, which in turn affects weather conditions.
*For the east coast of the USA, during the winter, this means cooler
temperatures and increased precipitation.
*The west coast of the USA is also very wet.
*It also means a less active Atlantic hurricane season.
Video Link:
http://educati
on.nationalgeo
graphic.com/e
ducation/activi
ty/the-oceanand-weatherel-nino-and-lanina/?ar_a=1
La Nina
*La Nina is a weather phenomenon where there is
unusual cooling of the surface water in the eastern
Pacific Ocean near the Equator.
*This occurs sometimes in December, every 3-5 years,
lasting for 9-12 months.
Effects of La Nina
*The jet stream is pushed north during this time and this affects the
track of storms, which in turns affects weather conditions.
*For the east coast of the USA, during the winter, this means warmer
temperatures and less precipitation.
*It also means a more active Atlantic hurricane season.
Summary
*We are currently expected to experience an El Nino
pattern beginning this month.*
Review:
*What is the difference between El Nino and La Nina?
*What are east coast winters like during each pattern?
*During which pattern is the Atlantic hurricane season
more severe?