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Climate in Canada !
Why does Canada have so much
climatic variety?
Average Annual Temperature:
Alert, Nunavut (Ellesmere Island) : -18°C
Pelee Island, Ontario: 9°C
Yellowknife, NWT: -5°C
Four Basic Facts:
1. Canada extends for a great distance from north to south
2. Different elevations produce different climate conditions
3. Coastal regions have different climates from inland regions
4. Wind and pressure systems move weather conditions from
one part of the country to another
Weather vs. Climate
Weather: Day to day condition of the atmosphere,
- short term – 5 to 7 days
- small area - cities
- difficult to predict – 5 day forecast
Ex. Temperature, humidity, precipitation, wind speed, cloud
cover, air pressure.
Climate: Patterns of weather which have occurred over a
long period of time
- long term - years
- large areas – countries, continents, the globe
- easy to predict – summer, winter etc
Ex. continental climate, maritime climate, arid climate.
Climate
Graph
30
140
25
130
20
120
15
110
10
100
Temp.
5
90
0
80 Precip
70 (mm)
(oC) -5
-10
60
-15
50
-20
40
-25
30
-30
20
-35
10
-40
J
F
M A M
J
J A
S
O N D
0
Months
TORONTO
J
F
M
A
M
J
J
A
S
O
N
D
Temp (oC)
-5
-4
0
4
10
16
19
17
14
9
2
-1
Precip(mm)
56
53
53
56
56
61
76
56
58
56
58
56
• Vancouver is further north than Toronto yet it is
warmer and wetter in winter.
• Montreal is just a little bit north of Toronto yet it
is much colder in winter
Why?
Factors that affect Climate:
Latitude
Ocean Currents
Winds and Air Masses
Elevation (Altitude)
Relief
Near Water
1. Latitude
Solar energy delivered by sunlight varies with
latitude - Intensity.
• At higher latitudes (ie. north pole), the
solar energy is less concentrated, spread
over a larger surface area….cooler
• At lower latitudes (ie. equator), the solar
energy is more concentrated, spread over a
smaller surface… warmer.
Latitude cont’d
Your position on the Earth determines the
amount of Solar Radiation (solar energy)
This is Intensity
Latitude (cont’d)
SEASONS
The earth is always at a 23.5 degree tilt.
The northern hemisphere changes from being
tilted toward the sun (summer) to being tilted away
from it (winter) – Duration.
Summer Solstice - most direct sunlight at most
northern point from equator. Days are longer. June
21-22.
Winter Solstice - most direct sunlight at most
southern point from equator. Days are shorter.
December 22-23
Latitude (seasons)
Take a moment, and be Amazed, by the
following website…
This site shows what the Earth looks like at
THIS MINUTE from different perspectives (from
the moon, the sun, night side, map view)
Hint: Think about how our earth is tilted at this
time of year...
http://www.fourmilab.to/cgi-bin/uncgi/Earth
2. Ocean Currents
Warm and cold pockets or streams (currents) of water
that move throughout the ocean.
• If a cold ocean current passes by, it will cool the
surrounding air.
• If a warm ocean current passes by, it will warm the
surrounding air.
• Ocean currents affect precipitation
See Map page 147
Major Ocean Currents
Average Temperatures in Winter - the lines
are called Isotherms. Compare Toronto to
Rome.
3. Winds and Air Masses
A large volume of air with almost the same
temperature and moisture throughout. An air mass
takes climate conditions from one place to another.
Eg. An air mass originating from the Arctic is cold and dry.
It moves southward and is carried by the westerly winds,
bringing cold dry air across Canada.
Front: The boundary between two air masses with different
temperature and and moisture content.
WARM FRONT – the leading edge of a warm air mass
COLD FRONT – the leading edge of a cold air mass
See Map page 147
Air Masses,
which have
specific Pressure
and Temperature
characteristics
are what effects
our climate.
Wow,
Temperature,
pressure, wind it’s all
connected!
You should
remember the
summer and
winter
effects of
the Jet
Stream on
Toronto.
The weight of air – Air Pressure.
Low Pressure - associated with warm air that
has expanded and is rising.
High Pressure - associated with cold air that
has contracted and is falling.
Winds move from High pressure to Low
pressure - See Hadley cell.
Wind Systems
(prevailing winds)
See page 148
Winds – cont’d
The movement of air from an area of High Pressure to
Low Pressure
Winds are created by differences in air pressure. Around
the world there are belts of low and high pressure. As
they move around each other, they create a wellestablished pattern of prevailing winds that blow from
West to East in Canada.
Prevailing winds - Winds that blow in almost constant
direction at these latitudes. In Canada, the prevailing winds
blow from west to east. These are called “westerlies” and
move air masses that affect our climate.
Winds (cont’d)
Why do the winds not simply blow directly north and south
between these belts?
• Winds are affected by the rotation of the earth.
This is called the CORIOLIS EFFECT.
Instead of winds moving in one straight north/south line
they are deflected to the right in the NORTHERN
Hemisphere and to the LEFT in the SOUTHERN
HEMISPHERE.
This is due to the rotation of the earth (eastward).
Hence, we have “westerlies” instead of “northerlies”!
Winds (coriolis effect)
The earth rotates
eastward. This force
changes the expected
path of the wind.
4. Elevation (Altitude)
Elevation: refers to how high or low we are on the earth’s
surface. The earth’s surface is our source of heat. The sun heats
the earth and in turn the earth heats us.
Air heats up, becomes less dense, rises, air pressure drops,
air expands, and heat is lost…Now it will COOL…until it
condenses.
Rate of Temperature Drop BEFORE condensation:
1 degree celsius / 100 meters
Rate of Temperature Drop AFTER condensation: 0.6
degrees celsius / 100 meters
5. Relief
Relief: refers to differences in elevation caused
by features on the landscape, for example, a
mountain range is type of relief. Even a small
barrier like a building can cause a temperature
difference.
Mountain ranges act as barriers to the movement
of air masses. They also cause precipitation to
occur (called Relief or Orographic Precipitation)
6. Effect of Large Bodies of
Water
Moderating Effect:
• Water heats up and cools down more slowly than
land.
• In the summer, wind blowing from the water will be
cool.
• In the winter, wind blowing from the water will be
warmer.
Places near large water bodies are MODERATE they do not get as cool or as warm as others
Maritime: Warmer and Wetter
Continental: Cooler and Dryer
Weather Maps: (Monday, Jan. 5, 2009)
Use of Icons
Note: The Westerlies push the weather
systems .
Location of the Jet
Stream, Cold and
Warm Fronts, High
and Low Pressure
Weather Forecasts:
Soil and Vegetation
• Soil is a naturally occurring, unconsolidated or
loose material on the surface of the earth, capable
of supporting life
• Soil is made up of four components (MOMA):
–
–
–
–
Minerals
Organic Material
Moisture
Air
N
Canada
Soil Quality
Soil and Vegetation
• Vegetation is a general term for the plant life of
a region that grows naturally (which very much
depends on Soil quality and of course Climate)
• Canada is a country of grass and trees:
– Coniferous trees
– Deciduous trees
Canada
N
Vegetation Regions
Yukon
Territory
Northwest
Territories
Tundra
West Coast Forest
Boreal Forest
Broad-leaved Forest
Grassland
Mixed Forest
Parkland
Cordilleran Vegetation
Nunavut
Quebec
Manitoba
Alberta
Ontario
Ecozones
• An ecozone is an area of the earth’s surface that
has a unique combination of plants, wildlife,
climate, landforms, and human activities.
• If you were to overlay or combine the climate,
landforms, soil (and vegetation) maps of Canada
shown in this slideshow, you would see patterns
emerge resulting in Canada’s 15 terrestrial (land)
ecozones
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The End!