Geoscience Reference
In-Depth Information
6.
Efforts are currently under way to more systematically
develop solar energy to supplement energy supplies.
This supply of energy is renewable and environmen-
tally friendly because its production does not result
in CO
2
emissions. Unfortunately, current technology
is inefficient, and the production of solar energy is
hampered in many places because the Sun shines
inconsistently.
C h e C k Y o u r u n d e r s t a n d i n g
1. Discuss the various components of the electromagnetic
spectrum.
9. How does the angle of incidence vary by latitude?
10. If the axis of the Earth were perpendicular to the plane of
the ecliptic, how would net radiation change at high lati-
tudes? Would these regions have a greater net surplus
or net deficit of radiation?
2. Are wavelengths in the visible part of the electromag-
netic spectrum short or long?
3. Why does the Sun emit shortwave radiation, whereas
Earth emits longwave radiation?
11. Why does the zone of net radiation surplus migrate (on
Earth) over the course of the year?
4. What are the constant gases in the atmosphere, and
why are they important?
12. Describe the global radiation budget. What are some of
the things that happen to solar radiation when it reaches
Earth? Why is there a global balance in the radiation
budget?
5. List the variable gases and describe why they change
with respect to their proportion of the atmosphere.
6. Why is the sky blue during the day, but red and orange at
dawn and dusk?
13. Describe the pros and cons of solar energy production.
Why is it considered to be renewable and environmen-
tally friendly? What are the major limitations to the pro-
duction of solar energy?
7. Compare and contrast the methods of heat transfer.
8. Describe some of the variables that influence the amount
of radiation that is absorbed on Earth.
ANSWERS TO VISUAL CONCEPT CHECKS
V i s u a l C o n C e p t C h e C k 4 . 1
Solar energy is produced by the process of nuclear fusion within the Sun. In this fashion, hydrogen
is converted to helium at very high temperatures and pressures. Solar radiation travels in the form of
electromagnetic energy at 300,000 km (186,000 mi) per second. It reaches Earth in about 8 min.
V i s u a l C o n C e p t C h e C k 4 . 2
This factory is producing a variety of particulates and variable gases that are streaming into the atmo-
sphere. Some of these industrial by-products will cause solar radiation to be reflected, whereas others
will cause absorption or scattering of electromagnetic radiation.
V i s u a l C o n C e p t C h e C k 4 . 3
This map of net radiation reflects patterns observed at either equinox. Note that the highest values of
net radiation are received in the tropical regions, which reflect the location of the subsolar point and a
maximum (90°) Sun angle. Such relationships can only occur along the Equator during the Spring and
Fall Equinoxes.
