Can someone explain? Why is it that in the Northern horizon, the sun's altitude was the greatest?

49.7 degrees

At a north latitude of 40.3 degrees, the maximum altitude of the Sun is 49.7 degrees on the Vernal and Autumnal Equinoxes. This is because the Sun is crossing the celestial equator on those days, and the maximum altitude of the celestial equator is simply 90 degrees minus your latitude

the correct answer: the index of refraction of the second medium is lower i tried this persons answer and it was wrong this person is lying