How to find sun’s height above
horizon?
By Aurimas Valancius III e
2012
Ecliptic
• The apparent yearly path of the Sun through
the stars is called the ecliptic.
• This circular path is tilted 23.5 degrees with
respect to the celestial equator because the
Earth's rotation axis is tilted by 23.5 degrees
with respect to it’s orbital plane.
Solstice
• The farthest northern point above the
celestial equator is the summer solstice, and
the farthest southern point is the winter
solstice.
• The winter solstice usually occurs on
December 21 to 22 each year in the Northern
Hemisphere, and June 20 to 21 in the
Southern Hemisphere.
Equinox
• The ecliptic and celestial equator intersect at
two points: the vernal (spring) equinox and
autumnal (fall) equinox.
• The Sun crosses the celestial equator moving
northward at the vernal equinox around
March 21 and crosses the celestial equator
moving southward at the autumnal equinox
around September 22.
Targets
• To find sun’s height above the horizon in
equinox.
• To find sun’s height above the horizon in
Solstice.
• To find sun’s height above the horizon in
March 5.
• To compare results.
Hypothesis
• I think, that sun’s height over the horizon will
be the highest in summer.
The way
• On the equinoxes the Sun moves along the
horizon.
• The easiest way to find sun’s height over the
horizon is when she is in equinox.
– March 21
– September 23
Equinoxes
• I need this formula:
celestial
equator
N
–
- the Sun's maximum
angular distance
– - geographic latitude
– - The Sun’s height over
the sky equator is 23.5
degrees.
horizon
Earth
S
Equinox
• I found the Sun’s height over horizon in
equinox:
550
Solstice in summer
• If I want to find sun's height when she is in
solstice. I need to find .
-
06-22
-
09-22
03-21
+
+
12-23
Solstice in winter
• I found Sun’s height over horizon in winter.
-
06-22
-
09-22
03-21
+
+
12-23
Sun's height above the horizon on
March 5
• I found Sun's height above the horizon on
March 5 in Taurage.
-
06-22
09-22
-
03-21
03-05
+
+
12-23
-
• I found .
06-22
-
N – day number after March 21.
09-22
03-21
351
+
+
12-23
Sun's height above the horizon on
March 5
• I found Sun's height above the horizon on
March 5 in Taurage.
-
06-22
-
09-22
03-21
+
+
12-23
Trutnov
• I found Sun's height above the horizon on
March 5 in Trutnov.
500
Madrid
• I found Sun's height above the horizon on
March 5 in Madrid.
400
Nuremberg
• I found Sun's height above the horizon on
March 5 in Nuremberg.
490
Athens
• I found Sun's height above the horizon on
March 5 in Athens.
370
Results
Day
Results
Equinox
350
Solstice in summer
58.50
Solstice in winter
11.50
March 5
City
Results
Taurage
32.530
Trutnov
37.530
Madrid
47.530
Nuremberg
38.530
Athens
50.530
Inference
• My hypothesis had reasserted.
• On the summer solstice the mid-day shadows
are much shorter because the Sun is much
higher above the horizon.
• is same in all countries, but isn’t.
• Sun’s height is the biggest in Athens.
Thank you for your attention