Can someone explain to me how the projection of the sun’s orbit affects the solar day?

Answer

If the Earth’s axis were perfectly perpendicular to the orbital plane…
– there would be no seasons
– the sun would be exactly 12 hours above and 12 hours below the horizon every day of the year
– the sun would always rise exactly in the east and set exactly in the west
– the sun would climb the same high in the south every day, namely 90° – the north latitude
So we would no longer have any reason to travel all at once in July and August, or to go skiing together in January. Every day would look like the 21st of March or the 21st of September in terms of sun. However, it would probably never snow again in our regions, because of no winter, and no heat wave because of no summer.

You can see that the tilted earth’s axis has quite a few consequences.

The 2nd figure on

http://journeytothestars.wordpress.com/2012/03/20/march-equinox-2012/

shows all this for our latitude of about 50° north. (The figure is copyrighted by a major publisher and so I can’t just copy it on this website)

• On March 21 and September, the sun rises in the east and sets in the west, and is 12 hours above the horizon. It then rises at 40 degrees in the south.
• It rises in the northeast on June 21, rises to 63° in the south and sets in the northwest. She stays above the horizon for almost 16 hours
• On December 21, it rises in the southeast, rises to 17° in the south and sets in the southwest. She only stays above the horizon for 8 hours