Download Path of the Sun

LO: How can we display the
different patterns that the sun
takes throughout the year?
• Do Now: What is the intensity of insolation
throughout the following dates: (High, Low,
or Medium)
–
–
–
–
January____________
December__________
March_____________
June______________
Relationship of Surface Temperatures to
Insolation
- Surface temperatures vary throughout each year
and throughout each day.
- These variations depend on a balance between
energy gained from insolation and lost by Earth’s
surface radiation.
- More energy gained than radiated = temperatures
rise.
- More energy radiated than gained = temperatures
decrease.
Times of Yearly Maximum and Minimum Temperatures
- The maximum intensity of insolation occurs on
June 21st but the maximum temperatures occur in
late July early August.
- Between June 21st and the end of July the Earth is
still gaining more energy than it is losing.
- The minimum intensity of insolation occurs on
December 21st but the minimum temperatures occur
in late January early February.
- Between December 21st and the end of January
the Earth is still losing more energy than it is
gaining.
Times of Daily Maximum and Minimum Temperatures
- The maximum intensity of insolation is at solar
noon but the maximum temperatures occur between
2p.m. and 4p.m.
- The Earth is still gaining more energy than it is
losing from 12p.m. to 4p.m.
LO: What is Insolation?
100
90
70 80
60 70
50 60
50 50
40 40
30 30
20 20
10 10
10
0
LO: What is Insolation?
Insolation or surface radiation
Temperature
Maximum Temperature
Insolation
Minimum Temperature
Heat Balance
Heat Balance
Earth surface radiation
12
Mid
2
am
4
am
6
am
8
am
10
am
12
pm
2
pm
4
pm
6
pm
8
pm
10
pm
12
Mid
Seasons
Direct causes of Seasons
- Seasonal changes in weather conditions result
from the cyclic variation in angle, intensity and
duration of insolation throughout the year.
- The seasons follow the shift in the 90°
insolation between 23½°N and 23½°S.
- This causes seasons to be opposite of each
other in the northern and southern hemispheres.
Astronomical causes of seasons
Tilt of Earth’s axis
-The Earth’s axis is tilted 23½° which causes the
90° insolation to shift between 23½°N and
23½°S.
- If the tilt of Earth’s axis was more, the 90°
insolation would reach farther north and south
resulting in warmer summer and cooler winters.
- If the tilt of Earth’s axis was less, the 90°
insolation would not reach as far north or south
resulting in cooler summers and warmer winters.
Parallelism of Earth’s Axis
- Regardless of Earth’s position in its orbit
Earth’s axis always point in the same direction.
- The north pole always point to the North Star
(Polaris).
Revolution of Earth Around the Sun
- As the Earth revolves around the sun the tilt of
the axis changes with respect to the sun.
- June 21st  Northern hemisphere tilted toward
the sun.
- December 21st  Southern Hemisphere tilted
toward the sun
- March 21st + September 23rd  Neither
hemisphere tilted toward the sun.
LO: What is Insolation?
50°N
0°
10°N
0°
50°S
23½°
N
10°S
23½°N
0°
90°
90°
90°
23½° N
0°
23½°S
0°
23½°
S
23½°
23½° S
23½°N
90°
0°
23½°S
How can we draw the different
paths of the sun?
Summary
• Complete the 4 Regents Questions on
your sheet!
LO: Heat Budget Lab
Do Now: Copy the following definitions:
1)Analogy: comparison between two things.
2)Arbitrary: an unspecified value.
3)Deficit: having less than necessary.
4)Surplus: having more than necessary.
5)Radiative Balance: The relationship between
the amount of energy reaching an object (or a
portion of it) and the amount leaving it. A good
example of this is our Earth receiving energy from
the sun, and giving off energy into the near future.