Why is the Sun's altitude (at noon) the most important cause of the seasons?

Question

Why is the Sun's altitude (at noon) the most important cause of the seasons? I heard this and was wondering what the answer was.

Answer 1

I get it now.  My bad =P

Answer 2

the sun's altitude has nothing to do with seasons. It has to do with the Earth's spin and rotation. The Earth spins on a tilt and the orbit is eliptical, so winter in N. America will be when the Earth is farthest away from the sun and tilted away. And vice versa.

Answer 3

The altitude of the sun determines how much energy we get.  The lower the angle, the less energy.  So when the sun is tracking low in the sky, that will be our winter because of the low average angle and lower amount of energy.  It is also a time when the surface is exposed to sunlight for a shorter period of time each day.  Both of these factors, length of daylight and angle, are the cause of the seasons.

Nerdy twit, when she says altitude, she is referring to the angular height of the sun from the horizon.  That is a legitimate measure in the alt-az coordinate system.  What you said about this being the result of the earth's axial tilt is correct, of course.

Answer 4

By "altitude" I presume you mean how close it gets to zenith (the point directly overhead), or its angular elevation.  The more directly overhead, the more sunlight the surface is exposed to, called insolation.  if the sun is lower in the sky, there is less insolation.

The truth is, however, it is not related to the time of the seasons at all.  The summer solstice on June 21st has the sun most directly overhead at noon, _and_ the longest day, but it is not the hottest day of the year.  In fact, the warmest days of summer occur in August, a month and a half later.  Most of us think of June 21st as the "beginning" of summer, even though the days get shorter and the sun gets lower immediately afterwards.

The reason for the time delay is that it takes some time for the peak insolation near June 21st to warm up the oceans and surface, so I would say that in fact the oceans, because of their ability to absorb so much heat, that are the most important cause of the seasons as we know them.