PORTLAND, Ore. (KOIN) – Now is the time to revisit our relationship between the sun and Earth.
It’s starting to get darker in the Pacific Northwest (PNW) and winter is right around the corner. You may be looking at the title of this lesson with an answer already. If you’re thinking the sun, you’re thinking correctly. Honestly, I can’t stress it enough: “Without the sun, there is no weather fun.”
There’s no doubt the tilt of the earth gives us our seasons. Throughout the year the two hemispheres (northern and southern) take turns having more exposure to the sun and closeness to the sun. Do you know your latitude?
Sometimes just going through the day-to-day routine we forget about all the science that is going on. The relationship between the sun and Earth is very important to our success at humans. We will just focus on the impact on our local weather. You know, as winter moves in the temperatures start to drop. You have to find your favorite winter jacket and winter hat to wear before you leave the house. You have to battle wind chill and that winter precipitation. You may just think it’s the daylength that is the reason for this. It’s dark so early! We will discuss that down in the lesson, but first, sun angle.
Why does the angle matter?
Think about the way the sunlight casts on the Earth’s surface for a minute. It can beam straight or it may come at an angle. You can think of these two concepts as oblique and direct sun.
Oblique: Sunlight that strikes the Earth at an angle and is spread over a relatively large area. Less intense, low sun.
Direct: Sunlight that strikes the Earth directly. More intense, high sun.
Have you ever put your hand directly under a light and felt the heat? What if you take that light and tilt it towards your hand, still receiving light, but you won’t feel that heat the same way because it won’t be hitting your hand as direct.
Can you think of another reason why direct or angled sunlight would make a difference?
Sunlight that spreads out and must heat a larger region will also deal with more of the atmosphere. This will lead to more light scattered and absorbed.
We are familiar with this concept because we know that December (our winter) and June (our summer) are much different from each other in the mid-latitudes. The sun angle is lower and the day length is shorter in the winter; meanwhile, the summer is higher in the sky and the day length is longer. More time with the sun means more energy to work with. The summer sun angle is more direct and we are off to the races.
It is evident, that the temperatures at our winter solstice, averages out to the mid-40s during the day and the mid-30s right before sunrise. By the time we reach the summer, our average high temperature is in the mid-70s and the morning temperatures are in the mid-50s.
The good news, once the winter solstice arrives, we start to gain day length! We also have a chance for winter precipitation: SNOW!
PAIR THIS LESSON WITH OUR “SEASONS” SEGMENT HERE!!