Have you ever thought about how the sun affects the temperature? We know that the sun supplies light and heat for the Earth, but how? What happens when the sun’s rays are blocked? Let’s learn more about how the sun keeps us warm.
Have you ever been outside on a warm sunny day, and suddenly the sun goes behind a cloud and the temperature feels like it drops several degrees? Then, you’ve experienced the energy of the sun and what happens when that energy is blocked.
The Earth gets it’s heat from the energy contained in rays of sunlight. Take that energy away and the amount of heat given to the Earth decreases. That’s what happens when clouds block even a small amount of the sunlight. The clouds not only block the sunlight, they block the energy needed to increase the temperature.
To learn more about how the sun creates energy, check out this lesson –>How Does The Sun Create Energy?
Sunlight Changes With The Seasons
When rays of sunlight hit the earth, the earth itself warms up. This, in turn, warms the atmosphere. This is the actual temperature we feel and measure with a thermometer.
The temperature of the earth’s atmosphere is also determined by the angle at which the sunlight hits the earth. No matter what the season – summer, winter, spring, or fall – the same sun with the same amount of brightness shines on the earth. So, if the sunlight is just as bright at all times of the year, why are the temperatures so different?
In the summer, the sun is directly overhead and its rays hit the earth directly. In the winter months, the sun sits lower on the horizon. This causes the rays to hit the earth at an angle. It’s the angle of the rays of sunlight that makes the difference in how they heat the earth.
The winter rays hit the earth at such an angle that they travel a longer distance through the atmosphere than the direct path the rays travel during the summer months. The longer distance traveled causes some of the energy from the sun’s rays to disperse through the atmosphere so that when the sunlight hits the earth, it does not have as much energy as the sunlight that hits the earth in the summer. That means the sunlight won’t warm the Earth as much in winter as it does in the summer.
Related post: Solar Printing STEM Activity
Demonstrating Sunlight Hitting The Earth
Try this activity with your students to demonstrate the way sunlight hits the Earth at different times of the year. They can actually see what a difference the angle of the sunlight makes.
Grab a flashlight and a piece of white paper. Hold the flashlight directly over the paper. This demonstrates the sun shining directly onto the earth in the summer months. Notice the circle of light on the paper. You might even want to trace the circle with a pencil.
Next, tilt the flashlight so that the light hits the paper at an angle. Notice that the light is not as bright as before and the light is more spread across the paper. This demonstrates the angle of the sun during the winter months. Trace this area of light if you want. Then, compare the two areas you outlined.