Expert: Steven LJ Russo - 3/8/2008

Question
QUESTION: Hello Steven
As common an experience as the passing of the sun through the sky is, I can't find out this simple thing: as the season changes the sun rises from a different point on the horizon, but does it ascend from the horizon at a different angle?  Regards John


ANSWER: It will rise and set at the same angle.

For example, if the Sun rises 90 degrees east, then it will set at 90 degrees west.  

If it rises 20 degrees south of east, then it will set 20 degrees south of west.

Steve


---------- FOLLOW-UP ----------

QUESTION: No, Steve, I mean the angle to the horizon, not the azimuth.

John


ANSWER: John:

Oh, O!.

Well, the answer is yes.

For example, the angle that ir rses in the winter, will be smaller than the angle that it rises in the Summer.

This is why the Summer "path" of the Sun is higher, and the Winter path is lower.


Steve

---------- FOLLOW-UP ----------

QUESTION: If it rose from the same point in the horizon it would need to rise at different angles to get to different noonday zeniths. But the sunrise point shifts so far north with approaching summer and vice-versa in winter (at least in such latitudes as Ireland) that maybe the angle to the horizon could remain the same and still make the various zeniths. I recall seeing a photo of superimposed timelapses in which the path of the rising sun for various days could be compared, and I noticed the paths seemed to be pretty well parallel to each other.

Answer
John:

Now I understand your question a bit better.

Yes, you are correct!

The angle IS the same.

Thinking back to a planetarium lesson that I do several times a year that has to do with the Sunrise and Sunset, the angle IS the same.  But because it rises further N or S of East, the path is longer or shorter and thus higher or lower in the S at noon.  And yes, the paths will be parallel.

So the angle IS the same for any given latitude.

IF you went to the Equator, the angle would be different from, lets say, NY.

Steve