Weather dynamics is the study of how water and air cause weather patterns. The atmosphere is made up of layers, with weather occurring in the troposphere closest to Earth's surface. Prevailing winds are large wind patterns affected by factors like the Coriolis effect and help distribute energy globally. Jet streams are fast moving currents of air in the upper atmosphere that influence weather. Major ocean currents also impact weather by transporting warm and cold water from the equator to poles.

1. Weather Dynamics

2. SOME GENERAL TERMS
• WEATHER DYNAMICS is the study of
how water and air cause weather
patterns.
• WEATHER
– The short-range forecast; daily conditions.
– Ex: temperature, precipitation, wind,
humidity, UV
• CLIMATE
– Long-term seasonal trends averaged from
annual data
– Ex: In the Atlantic Canada Climate
region, winters are cold and
summers are Warm

3. THE ATMOSPHERE
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4. What is the Atmosphere?
DEFINITION:
• The blanket of air and water vapour that
surrounds the Earth.
• If the earth were an ONION, the atmosphere
would be like the ONION PEEL.
• It is about 500 km thick, containing 78% N ,
21% O , and some trace elements (ex: CO2,
H2O, Ar).

5. LAYERS OF THE ATMOSPHERE
• Defined according to ALTITUDE, or
elevation above sea level.
• TROPOSPHERE
– 8-16 km altitude, layer closest to earth’s
surface
– This layer is the most dense, meaning it
contains the most particles.
– Weather occurs in this layer.
– Temperature ranges from 20 to -50degrees
Celsius.
– The tropopause is on the upper end of this
layer.

6. ATMOSPHERIC PRESSURE
• Defined as the pressure that air particles
exert as gravity pulls them toward the
centre of the earth
• Air pressure is greatest at sea level where
air is most dense (i.e., thick)
• Air pressure decreases with altitude.
– Thus, if you climb a mountain, the weight of
the air above you is less, and the pressure is
less.

7. WINDS
• Wind is the movement of air in the
atmosphere.
– Some winds are local while others are
prevailing.
• Local winds occur in a fairly small
region.
• Prevailing winds are wind patterns that
affect large regions around the world.

8. PREVAILING WINDS
• In the early 1800s, SAILORS discovered
that, in certain areas, the winds blow in the
same direction all of the time.

9. THE CORIOLIS EFFECT
• The change of DIRECTIONof a moving
object in a constantly rotating system.
• The rotation of the EARTH deflects
moving air AND water to the RIGHT of its
initial direction in the Northern Hemisphere
(opposite in the Southern Hemisphere).
– Note:
• This direction of deflection is from the viewpoint of the
starting position of WHAT IS BEING DEFLECTED (ex:
plane, wind, etc.).
– FIGURE 2 - pg. 517
– FIGURE 1 - pg. 525

10. THE CORIOLIS EFFECT

11. Prevailing Winds in the Northern Hemisphere
• Prevailing Winds help distribute energy and
moisture around the globe.
• TYPES IN NORTHERN HEMISPHERE
– Polar Easterlies
• Cold easterly winds blow from the poles to 60 degrees.
– Mid-Latitude Westerlies
• Warm, moist winds blow from the west
• NEWFOUNDLAND is affected by these.
– North East Trade Winds
• Winds that blow toward the equator

12. JET STREAMS
• Fast moving riversof air that race across the high
altitude sky, sometimes at speeds as high as 400
km/h.
• Jet streams occur about 7000 m up in the upper
regions of the troposphere.
• They consist mostly of westerly winds, and are
caused by strong differences in pressure and
temperature.
• Air at the equator is thickerand moves from high to
low pressure areas (i.e., N or S of the equator).
• Jet streams can be thousands of miles long,
hundreds of miles wide, but only a mile or so deep.

13. JET STREAMS
• Pilots can reduce flight time by hitching a ride on a jet
stream.
• Long lines of clouds often indicate the presence of a jet
stream.

14. MAJOR OCEAN CURRENTS
• Oceans have a HUGE effect on weather
patterns. Here are just a few of the ways
water is significant in this regard:
– Oceans are heat sinks since most of the
sun’s direct rays hit water.
– If water is warm, air above it is warm,
meaning lots of moisture. If water is cold, air
above it is cold.
– Warm water is constantly moving from the
equator to the poles.
– Cold water is constantly moving from the
poles to the equator.

15. MAJOR OCEAN CURRENTS
• Which ones influence NEWFOUNDLAND
weather? __________________________

16. WHAT CAUSES OCEAN CURRENTS?
• Convection currents
• Winds across oceans
• Earth’s rotation
• Shape of continents
• Heat capacity of Water
• Amount of salt in oceans