Geoscience Reference
In-Depth Information
N
N
Tropic of
Cancer
Tropic of Cancer
Equator
Equator
Tropic of
Capricorn
Tropic of
Capricorn
Subsolar point
at Tropic of
Cancer
Subsolar point
at Equator
S
S
(a) March 21
(b) June 21
N
N
Subsolar point
at Equator
Tropic
of Cancer
Tropic
of Cancer
Equator
Subsolar point
at Tropic of
Capricorn
Equator
Tropic of
Capricorn
Tropic of
Capricorn
S
S
(c) September 21
(d) December 21
Figure 3.13 Seasonal migration of the subsolar point.
Due to the tilt of the Earth's axis, the subsolar point migrates between the
Tropic of Cancer and Tropic of Capricorn over the course of the year. For perspective, imagine that the Sun is in front of Earth in (a)
and behind Earth in (c). Further, imagine that it is to the left of Earth in (b) and the right of Earth in (d). Also notice the orientation of
the circle of illumination at different times of the year.
VISUAL CONCEPT CHECK
3.1
N
Suppose the subsolar point is at 10° S latitude.
In other words, the Sun angle at that latitude is
90° at solar noon. Which of the following months
are logical times of the year when the subsolar
point would be at this latitude? Explain.
SUN'S RAYS
a)
October
b)
December
c)
February
Subsolar point
d)
June
