Water, Weather and Climate
Science 8
The energy that creates our weather comes from the sun. At the equator, the sun
reaches the Earth almost at a 90º angle. As you move toward the north or south poles,
the surface of the earth curves away from the sun. The light becomes more spread out
so less energy is received. If two cities are found at similar latitudes, they will receive
similar amounts of energy from the sun.
Which city will usually have a warmer climate – one at latitude 25ºN or one at latitude
65ºN?
The city closest to the equator (at 25ºN) will get more solar energy.
Why are the poles coldest in the winter?
The is NO solar energy to warm the land when there is 24 hours of darkness!
Heat capacity describes how much heat energy is needed to warm a substance.
Water has a very high heat capacity – it takes a lot of energy to warm it up. Soil and
rock have lower heat capacities than water, and air has a very low heat capacity.
Having large amounts of water nearby (like a large lake or ocean) can affect the
climate of an area. The energy from the sun changes with the seasons, but the
temperature of water changes slowly. This affects the temperatures on the land and air
nearby.
In the spring, when there is more sunlight available, which area will warm up first: the
interior of continents (with smaller water bodies nearby) or the coasts?
The continental interior warms up quickly, while the coasts continue to get cool or cold
wind from over the ocean
In the fall, when there is less sunlight available, which area will cool faster: the interior of
continents (with smaller water bodies nearby) or the coasts?
The continental interior cools quickly, while the coasts continue to get warmer wind from
over the ocean.
The change in temperature of a substance also depends on the amount (mass) of the
material. If you have a large mass of water, it takes a lot more energy to warm it than to
warm a small mass of water.
What will have more effect on climate – a lake or an ocean?
An ocean will affect climate much more than a lake (even the very large ones, like the
Great Lakes)
Currents near the shore have a large impact on climate. A warm current will create
warm, moist air that brings a lot of rainfall and mild temperatures. In Canada, you can
see this effect in coastal British Columbia where there is a lot of rainfall and mild winters.
It also causes mild winters in the United Kingdom.
A cold current will create cool air that warms up when it reaches shore and causes
water to evaporate from the land. You can see this effect on the west coast of Africa,
Australia and Southern California where deserts occur.
Answer the following questions on loose leaf.
1. Explain why the climate is warmer in southern Saskatchewan than in Northern
Saskatchewan.
Southern areas get more solar energy than northern areas due to the tilt of the
surface.
2. Yellowknife, NWT and Thunder Bay, Ontario are both located near lakes, but
Yellowknife has a much colder climate. Why?
Yellowknife is much farther north.
3. Explain why the spring months are warmer in Calgary, Alberta (51ºN) than in St.
John’s, Newfoundland (48ºN) even though Calgary is a bit further North.
In saint John’s, the nearby ocean remains very cold for a long time.
4. Explain why summers are hotter in Winnipeg than in Vancouver, even though
they are located at similar latitudes.
In Vancuover, the ocean remains cool through the summer, so there are few
really hot days.
5. Complete the climate graphs for City A and City B on the next page.
a. Which city (A or B) has hotter summers?
b. Which city (A or B) has colder winters?
c. Which city (A or B) has the most rainfall?
d. If both A and B have similar latitudes, which city is located near water?
City A has warmer summers (higher average temperatures)
City A has slightly colder winters (lower average temperatures)
City B gets much more rain (or snow)
If both cities are at the same latitude, then you would expect the continental interior to
have more extreme temperatures and less precipitation, so City A is in the interior, and
City B is probably on the coast.
Create climate graphs for the data given. Monthly precipitation is graphed as a bar
graph, using the scale on the left. Average temperature for each month is graphed as a
line, using the scale on the right.
City A
J
-7
46
Mean Temp. (ºC)
Precipitation (mm)
F
-6
46
M
-1
57
A
6
64
M
12
66
J
17
69
J
21
77
A
20
84
S
15
74
O
9
63
N
3
70
D
-3
66
150
25
120
20
90
15
60
10
30
5
0
0
-30
Mean Temp. (ºC)
Precipitation (mm)
City ___
-5
-60
-10
J
F
M
A
M
J
J
A
S
O
N
D
City B
J
F
M
A
M
-6
-6
-2
4
9
147 119 123 124 111
Mean Temp. (ºC)
Precipitation (mm)
J
15
98
J
18
97
A
18
110
S
14
95
O
N
D
9
3
-3
129 154 167
150
25
120
20
90
15
60
10
30
5
0
0
-30
-5
-60
-10
J
F
M
A
M
J
J
A
S
O
N
D
Mean Temp. (ºC)
Precipitation (mm)
City ___