Water, Weather and Climate

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?

Why are the poles coldest in the winter?

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?

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 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?

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.

2.  Yellowknife, NWT and Thunder Bay, Ontario are both located near lakes, but Yellowknife has a much colder climate. Why?

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.

4.  Explain why summers are hotter in Winnipeg than in Vancouver, even though they are located at similar latitudes.

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?

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

City B