Alolan_Apples
“Assorted” Collector
Winter, spring, summer, fall, I have just named them all. Today's entry is going to be another fact entry, and this time, it's going to be on the four seasons. We all may enjoy the changes in the season and all the activities each season, but today, I will go behind the scenes of the four seasons.
What is actually giving us our seasons? How are they so different? Why do the plants change colors in the fall? The answers will be revealed in this blog entry.
The actual reason why seasons change is because of the Earth's axial tilt. Everyday, it gradually changes until it gets to a maximum angle on one of the poles. The maximum angle the Earth's axial tilt is 23.5° away from or towards the sun. Once it hits the maximum angle, it will tilt back until it hits the other angle. The pattern continues on.
While one pole is closer to the sun, the other is away from the sun. Unlike the Earth's rotation, the tilt is much slower. 100% of the time, half the Earth is in the sunlit zone. The other half is in the shadow. But the same locations don't stay in the same spot all the time. The sun provides heat to the Earth. The longer one area is under the sun, the hotter it is. If an area has been under a shadow or on the edge of the sunlit zone for long, then it gets cold.
The reason why summer is hot is because the pole of the hemisphere is under the sun. With a greater deal of being under the sunlit zone, the days are longer than the nights, giving it a hot summer, especially since one of the tropical latitudes faces the most heat. When a polar region is engulfed in the shadow, the nights are longer than the days, giving the hemisphere cold weather.
As it tilts, there are three positions the Earth can go to. One of them is the Winter Solstice, where the North Pole is the furthest away from the sun as the South Pole is the closest to the sun. Days are the longest in the Southern Hemisphere and are the shortest in the Northern Hemisphere. The Tropic of Capricorn is the hottest. Another position is the Summer Solstice, where it's the other way around. The Tropic of Cancer is the hottest. The third position is the equinoxes. That's when both sides of the Earth get equal sunlight. The Equator is the hottest.
When the Earth tilts from the equinoxes to the solstices, then one side will have a spring while the other side has a fall. The spring side has warming temperatures, but the fall side has cooling temperatures. When it tilts from the solstices to the equinoxes, one side has a winter, but the other has a summer. The winter side has the cold temperatures as the summer side has the hot temperatures. Another interesting observance is that the side of the Earth's tilt winter is on is also the fall side, whereas the summer side is the spring side.
Now I will go over the reason why trees changes colors in the fall. So we all know that there are no leaves in the winter as flowers bloom and blossom in the spring. Leaves grow in the spring.
What happens is that the plants store food during photosynthesis. During photosynthesis, they stay green. But they only get photosynthesis during the hot days. Once the summer ends, photosynthesis is done for the year, so the plants use up their food sources. The green pigment generated through photosynthesis begins disappearing. It starts out as yellow. Then it turns orange, then red, and then brown. It cannot go further after brown, so leaves die after it uses up its food.
In case if you are wondering, the sun is actually brighter during one time of the year than it is during the other. The Earth's orbit around the sun is elliptical, but barely not a perfect circle. The point we're at the furthest from the sun is called Aphelion. When we're at the closest, we're at Perihelion. The reason why the sun is brighter at one time of the year is because we're closer to the sun, but not by a long shot. Even if we're at the closest, we're still over 0.99 AU away from the sun, but we are less than 1.01 AU during Aphelion.
The Earth is at Perihelion very early in the year, where it's winter in the United States and summer in the southern hemisphere. It's on Aphelion in the mid-year, were the northern hemisphere has a summer, but the other side has a winter. So if you're living in the northern hemisphere, you can understand why the winter sun is brighter than the summer sun.
An interesting observance is the sun's brightness and length of day. If you're living in the southern hemisphere, the sun is like a dimming light. The longer you keep a light on, the brighter it gets. So if the peak brightness is not as high, the light must've been on shorter. That's only because the Earth is at Perihelion in the summer and Aphelion in the winter. If you're living in the northern hemisphere, the sun is like an energy saver. The more energy you use at once, the shorter it will last. It looks like more energy is used in the winter because the sun is brighter when days are only shorter. In addition, days are longer in the summer as the sun isn't as bright, so more energy is saved. But that's because the Earth is at Aphelion in the summer and Perihelion in the winter.
That's all for today's entry. So once you finish reading, you probably have learned something new.
What is actually giving us our seasons? How are they so different? Why do the plants change colors in the fall? The answers will be revealed in this blog entry.
Axial Tilt:
The actual reason why seasons change is because of the Earth's axial tilt. Everyday, it gradually changes until it gets to a maximum angle on one of the poles. The maximum angle the Earth's axial tilt is 23.5° away from or towards the sun. Once it hits the maximum angle, it will tilt back until it hits the other angle. The pattern continues on.
While one pole is closer to the sun, the other is away from the sun. Unlike the Earth's rotation, the tilt is much slower. 100% of the time, half the Earth is in the sunlit zone. The other half is in the shadow. But the same locations don't stay in the same spot all the time. The sun provides heat to the Earth. The longer one area is under the sun, the hotter it is. If an area has been under a shadow or on the edge of the sunlit zone for long, then it gets cold.
The reason why summer is hot is because the pole of the hemisphere is under the sun. With a greater deal of being under the sunlit zone, the days are longer than the nights, giving it a hot summer, especially since one of the tropical latitudes faces the most heat. When a polar region is engulfed in the shadow, the nights are longer than the days, giving the hemisphere cold weather.
As it tilts, there are three positions the Earth can go to. One of them is the Winter Solstice, where the North Pole is the furthest away from the sun as the South Pole is the closest to the sun. Days are the longest in the Southern Hemisphere and are the shortest in the Northern Hemisphere. The Tropic of Capricorn is the hottest. Another position is the Summer Solstice, where it's the other way around. The Tropic of Cancer is the hottest. The third position is the equinoxes. That's when both sides of the Earth get equal sunlight. The Equator is the hottest.
When the Earth tilts from the equinoxes to the solstices, then one side will have a spring while the other side has a fall. The spring side has warming temperatures, but the fall side has cooling temperatures. When it tilts from the solstices to the equinoxes, one side has a winter, but the other has a summer. The winter side has the cold temperatures as the summer side has the hot temperatures. Another interesting observance is that the side of the Earth's tilt winter is on is also the fall side, whereas the summer side is the spring side.
Photosynthesis:
Now I will go over the reason why trees changes colors in the fall. So we all know that there are no leaves in the winter as flowers bloom and blossom in the spring. Leaves grow in the spring.
What happens is that the plants store food during photosynthesis. During photosynthesis, they stay green. But they only get photosynthesis during the hot days. Once the summer ends, photosynthesis is done for the year, so the plants use up their food sources. The green pigment generated through photosynthesis begins disappearing. It starts out as yellow. Then it turns orange, then red, and then brown. It cannot go further after brown, so leaves die after it uses up its food.
Aphelion and Perihelion:
In case if you are wondering, the sun is actually brighter during one time of the year than it is during the other. The Earth's orbit around the sun is elliptical, but barely not a perfect circle. The point we're at the furthest from the sun is called Aphelion. When we're at the closest, we're at Perihelion. The reason why the sun is brighter at one time of the year is because we're closer to the sun, but not by a long shot. Even if we're at the closest, we're still over 0.99 AU away from the sun, but we are less than 1.01 AU during Aphelion.
The Earth is at Perihelion very early in the year, where it's winter in the United States and summer in the southern hemisphere. It's on Aphelion in the mid-year, were the northern hemisphere has a summer, but the other side has a winter. So if you're living in the northern hemisphere, you can understand why the winter sun is brighter than the summer sun.
An interesting observance is the sun's brightness and length of day. If you're living in the southern hemisphere, the sun is like a dimming light. The longer you keep a light on, the brighter it gets. So if the peak brightness is not as high, the light must've been on shorter. That's only because the Earth is at Perihelion in the summer and Aphelion in the winter. If you're living in the northern hemisphere, the sun is like an energy saver. The more energy you use at once, the shorter it will last. It looks like more energy is used in the winter because the sun is brighter when days are only shorter. In addition, days are longer in the summer as the sun isn't as bright, so more energy is saved. But that's because the Earth is at Aphelion in the summer and Perihelion in the winter.
That's all for today's entry. So once you finish reading, you probably have learned something new.
