We have just passed the autumn equinox and what we call “the first day of fall.” It will be late December before fall officially ends at the winter solstice. On the first day of fall here in Michigan, it was unseasonably hot, and people were griping about “where is the cool fall weather we are supposed to have?” Long before the first day of winter on December 20-21, we will have snow. Is there something wrong with the seasons, or is the trouble with our understanding?
“Equinox” suggests that the length of the day is equal to the length of the night. The Sun is overhead at the equator, and from now until December 20 it will be directly overhead at progressively greater southern latitudes until it reaches just past 23 degrees south latitude. Here in the north, the Sun’s elevation above the horizon will get progressively lower, meaning that less and less of the Sun’s energy will strike the Earth’s surface so the weather will get cooler.
The problem with this simple picture is that there is a lag in the seasons. During the summer months in the Northern Hemisphere the lakes and oceans warm from the sunshine. Water has a high specific heat, so that heat is stored and is released slowly. That means we stay warm longer than expected in the fall. In the Southern Hemisphere the picture is complicated by the fact that the Earth is closer to the Sun during their summertime, so the radiation is more intense. That might be a problem except that the Southern Hemisphere has more water than the Northern Hemisphere because oceans cover more of the southern Earth’s surface. With that greater storage and absorption capacity moderates the temperatures in the Southern Hemisphere.
The autumn equinox reminds us of the incredibly well-designed system of the Earth. It is easy to over-simplify the seasons and the equinoxes and solstices, but the system functions remarkably well. Without that careful design, the weather picture would be far more unstable than it is. Proverbs 8:22-31 speaks of wisdom’s involvement in all of the creation. We are just now beginning to understand how the system works and how our use of Earth’s resources affect the system.
–John N. Clayton © 2017