UNIT 1: Weather
13.1: A Closer Look at the Earth
Water (70% of the earth’s surface), land (30% of the earth’s surface) and the
atmosphere all contribute to and regulate the weather and climate of a region. To make
sense of our planet, the earth is broken up into lines of latitude and longitude. Regions
with similar latitude often have similar seasonal patterns of weather.
Latitudes are the horizontal lines on the globe.
They are measured in degrees north or south of the equator.
Label the following latitudes on the diagram below:
The North Pole
90o N Latitude
The Arctic Circle
66.5o N Latitude
The Tropic of Cancer
23.5o N Latitude
The Equator
0o
The Tropic of Capricorn
23.5oS Latitude
The Antarctic Circle
66.5oS Latitude
The South Pole
90oS Latitude
13.2 The Energy Balance of the Earth
Our sun provides almost all the energy that sustains life on earth. This energy provides
the driving force for our weather. The Sun not only emits visible light (the red to purple
visible spectrum), but also emits other forms of electromagnetic radiation. Fortunately,
much of the sun’s energy does not reach earth or our planet would be too hot for life.
Energy Transfer
Energy that can be transferred by 4 methods. Briefly describe each method and give an
example:
Radiation:
Conduction:
Convection:
Advection:
The Electromagnetic Spectrum:
Electromagnetic radiation is made up of waves that travel at the speed of light through
space, such as visible light. Some forms are more powerful than light (ultraviolet waves, X
rays) and others are less powerful (infrared, microwaves).
Where does the Sun’s energy go?
When the radiation of the sun hits Earth, some is bounced off the atmosphere or ground
and reflects back into space. Some radiation is absorbed by the atmosphere, earth or
water.
What % of the Sun’s radiation is:
Reflected by clouds?
Reflected by the ground?
Absorbed by clouds?
Absorbed by land & oceans?
_____
_____
_____
_____
Questions:
1. Define the following terms using the textbook glossary (p.708):
a) albedo
b) heat sink
c) heat capacity
2. Give an example for each of the following:
a) a substance with a high albedo _______________________
b) a substance with a low albedo _______________________
c) a substance with a high heat capacity ________________________
d) a substance with a low heat capacity ________________________
3. Answer the following textbook questions:
p. 503 # 7 and 8
p. 507 #1 - 10
p. 509 #1 - 3
13.4 The Atmosphere
Our atmosphere is a gaseous blanket that covers the Earth. It is most dense at sea level
and exerts atmospheric pressure. A barometer is an instrument that measures
atmospheric pressure. The atmosphere has several distinct layers.
On the diagram, locate the tropopause and estimate the air temperature in each layer (see
Figure 3, p.511).
Read pages 510
describe the properties of each of these:
Troposphere
Tropopause
Stratosphere
Mesosphere
Thermosphere
Atmospheric Pressure
Pressure Gradient
Answer questions 3 – 6 on p. 510-513.
If this is complete, read ahead on pages 516-519.
– 511 and