HUNTSVILLE, Ala. — With the exception of allergies, those really smelly blooming trees, and the height of severe weather season Spring can be a great time of year in the Tennessee Valley. Temperatures warm and the amount of daylight gets longer. People are outside more and many warm-weather activities return to the Tennessee Valley.
Please take a moment to focus on the positives that Spring brings to the area and take a break from the negative that is Coronavirus.
Why do we have Spring? Why do we have seasons at all? Let me explain.
It all starts with the fact that earth is tilted on its axis. The earth is tilted 23.5°. This never changes. This is a big constant and is one of the big reasons we have the seasons.
Next, we can look at the different positions of the earth as it revolves around the sun in any given year. The earth does not revolve in a circle, instead, it returns in more of an oval.
This means the earth is closer to the sun at certain points of the year than others, but that is somewhat irrelevant. The earth is closest to the sun during the Winter Solstice and furthest from the sun during the Summer Solstice. what matters is the sun angle.
Through the year the sun angle changes, and it all goes back to the fact that the earth is tilted on its axis. During the summer solstice, the earth is tilted toward the sun and during the Winter solstice, the earth is tilted away from the sun.
When the earth is tilted toward the sun the sun angle is higher. When the earth is tilted away from the sun the sun angle is lower. A lower sun angle means the sun's energy is spread out over a greater distance.
Think of it this way. Take a cup of water and dump it straight out on the ground. There's one big wet spot. The angle you dumped it was higher. Now take a cup of water and throw it out in front of you. This time there is a wider wet area. The angle you dumped it was much lower. Higher angle = more intense energy. Lower angle = less intense energy.
The exception to this whole sun angle thing comes with the Vernal Equinox and the Autumnal Equinox. At these two points in the year, the earth is tilted neither toward nor away from the sun. Essentially the angle is the same for everyone.
There you have it! The seasons!