NAME:
13-Weather and Climate Notes CGC 1P1 and CGC 1D1
Read Chapter 12 in “Making Connections”
Weather: Day to day condition of the atmosphere
- short term –
- small area - cities
-
to predict – 5 day forecast
Temperature, humidity, precipitation, wind speed, cloud cover, air pressure
Climate: Patterns of weather that have occurred over a
of time
- long term - large areas – countries, continents, the globe
to predict – summer, winter
Examples: continental climate, maritime climate, arid climate
Why does Canada have so much climatic variety?
1. Canada extends for a great distance from north to south (4,500 km), from 41°N in Lake Erie to 83°N on Ellesmere
Island.
2. Canada has a
from sea level to 5,959 metres (Mount Logan).
3. The long
influence of the
and vast areas are a great distance from the modifying
.
4. Southern Canada is often the battle zone between
air from the south.
from Arctic regions and
, moist
Can you answer the question: Vancouver is further north than Toronto, yet it is warmer and has more precipitation. Can
you explain why this is the case? If you can’t answer it yet, hopefully you will be able to do so soon!!
Canadian Climate Map
Atlantic Maritime
Southeastern
Prairie
Boreal
Pacific Maritime
Cordilleran
Taiga
Artic
LEGEND: CLIMATE REGIONS
Factors that affect Climate:
Latitude
varies with latitude – different intensity.
Solar energy delivered by
At
latitudes (i.e. North Pole), the solar energy is
over a larger surface area…It is therefore
.
concentrated and spread
At
latitudes (i.e. equator), the solar energy is
smaller surface… It is therefore
.
concentrated, spread over a
This diagram is shows how the angle of incidence changes with latitude.
The earth is always at a
degree tilt.
The northern hemisphere changes from being tilted toward the sun
(
) to being tilted away from the sun (
).
Remember these from earlier in the year??
Summer Solstice - most direct sunlight is at the most northern point
from equator. Days are
. June 21-22
Winter Solstice - most direct sunlight is at the most southern point
from equator. Days are
. December 21-22
Ocean Currents
Ocean currents are
the ocean. They affect
and
pockets or streams of water that move throughout
.
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.
Winds and Air Masses
An air mass is a large
with almost the same
temperature and moisture throughout. An air mass takes on the
climate characteristics of the areas where it was formed.
Air masses move from
areas toward
areas. This moving air causes wind.
E.g. 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.
FRONTS: The
two air masses with different temperature and moisture content.
WARM FRONT – leading edge of a warm air mass
COLD FRONT – leading edge of a cold air mass
Air Pressure is caused by the weight of the
-
Low Pressure is associated with
High Pressure is associated with
Like Air Masses, Winds move from
.
air that has expanded and is rising.
air that has contracted and is falling.
pressure to
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 well-established pattern of prevailing winds that blow from
to
in Canada.
Due to the fact that the Earth is Rotating, we get what is known as the Coriolis Effect on the movement of the
air masses or wind. Instead of winds moving in one straight north/south line, they are deflected to the
in the NORTHERN Hemisphere and to the
in the SOUTHERN HEMISPHERE.
This is due to the rotation of the earth (eastward). Hence, we have “westerlies” instead of “northerlies”.
Prevailing winds: Winds that blow in almost
at these latitudes.
In Canada, the prevailing winds blow from
. These are called “westerlies”.
They move air masses that affect our climate.
The JET STREAM:
The JET STREAM is a band of
moving high
above the Earth's surface from west to east.
There are
jet streams in the Northern
Hemisphere. The polar jet stream is located at the boundary
between cold air to the north and warm air to the south.
Elevation
Elevation refers to how high or low we are on or above the earth’s surface. As you hike
up a mountain, the temperature drops.
Why does it get colder even though you get closer to the sun?
This is technically referred to as the
. The lower the elevation, or
altitude, the
the air pressure. As air rises, it expands because of lower
air pressure.
Air heats up, becomes less dense,
expands, and heat is lost…Now it will
expands, it cools.
. As air pressure drops, air
…until it condenses. As air
The Rate of Temperature Drop BEFORE condensation: (DRY LAPSE
RATE)
1 degree Celsius / 100 meters
Rate of Temperature Drop AFTER condensation: (WET LAPSE RATE)
0.6 degrees Celsius / 100 meters
Relief
Relief refers to
caused by features
on the landscape. For example, a mountain range is a type of relief. Even
a small barrier like a building can cause a temperature difference.
Mountain ranges act as barriers to the movement of
also cause precipitation to occur, called Relief or Orographic
. They
Precipitation.
Air is forced to
ground
100m.
over a hill or mountain. As air
up by the sun) the air cools by 1°C per
away from the heat source (the
As the water vapour in the air condenses, it forms clouds and
then rain. Air that has cooled cannot hold as much water as
warmer air.
The air starts to
begins to
down the hill or mountain and
up again.
As air
up, it can hold more water and as it has lost water through precipitation, the air has less
water overall. Therefore clouds disappear and rain stops. This side of the relief feature is known as a
RAINSHADOW.
Near Water
Moderating Effect of large bodies of Water:
Water
more slowly than land.
In the summer, wind blowing from the water will be
In the winter, wind blowing from the water will be
.
Places near large water bodies are MODERATE - they do not get as cool or as warm as others
– Wetter overall
Maritime Climate:
– Dryer overall
Continental Climate:
Precipitation and Temperature – CLIMATE GRAPHS
Climate Graphs - See p.141-144 in MAKING CONNECTIONS
STATION Jan.
A
Ave.
-14
Feb.
Mar.
Apr.
May
June
July
Aug.
Sept.
Oct.
Nov.
Dec.
Year
-11
-5
4
10
14
16
15
10
4
-6
-12
2.1
23
15
16
22
43
76
101
70
47
18
16
19
466
STATION Jan.
B
Ave.
-9
Feb.
Mar.
Apr.
May
June
July
Aug.
Sept.
Oct.
Nov.
Dec.
Year
-8
-3
3
9
15
19
18
13
7
2
-6
5.0
96
117
101
91
93
103
81
81
106
114
126
1229
Monthy
Temp ᵒC
Ave.
Monthly
Prec. mm
Monthy
Temp ᵒC
Ave.
Monthly
Prec. mm
120
1) Fill in your chart using the climate stations A and B from the data given above – see also Fig.12-22 (pg.144)
Location
Average
Temperature
Temperature
Range
Total
Precipitation
Seasons of
Maximum
Precipitation
Continental or
Maritime?
A
B
2) Draw the climate graphs for stations “A” and “B” - Be sure to use BLUE for the Precipitation Bar Graph, and
Use RED for the Temperature Line Graph
Precipitation in ________________
Temperature in ________________
Station “A”
J
F
M
A
M
J
J
A
S
O
N
D
Precipitation in ________________
Temperature in ________________
Station “B”
J
F
M
A
M
J
J
A
S
O
N
D
3) In which climate is each station located (maritime or continental)? Explain how you reached your
decision.
4) What climate factors do you think affect the climate the most at these stations?
5) What factors help us to decide if a location is in a maritime or continental climate?