The Reasons for the Seasons
- Seasonal Changes Our year is divided up into four seasons: summer, fall, winter, spring. ...
- It's Hotter at High Noon Too Earth's tilt also means that the Sun will appear to rise and set in different parts of the sky during different times of the year. ...
- Back to Proximity So, does it matter how close Earth is to the Sun? ...
- Key Takeaways ...
- Sources ...
What is the main factor responsible for seasons?
“ A season is a division of the year marked by changes in weather, ecology and hours of daylight. Seasons result from the yearly orbit of the Earth around the Sun and the tilt of the Earth’s rotational axis relative to the plane of the orbit.
What are the two main reasons Earth has seasons?
What are the 4 causes of seasonal change?
- Change of seasons is caused by:
- (a) variation in the angle of the Sun’s radiation due to the tilt of the Earth’s axis of rotation.
- (b) variation of distance of the Earth from the Sun due to the elliptical orbit of the Earth.
- (c) periodic variations in Solar activity.
Why is the four seasons so special?
- Attracting great staff. The people make the experience and Four Seasons has always done a great job of attracting talent.
- Focusing on the basics: A warm and genuine greeting, a comfortable bed, and hot eggs. ...
- Consistency: While there is differentiation in physical products there is a large degree of continuity and conformity in the guest experience.
How does the Sun cause the seasons?
Seasons are caused by the Earth’s revolution around the Sun, as well as the tilt of the Earth on its axis. The hemisphere receiving the most direct sunlight experiences spring and summer, while the other experiences autumn and winter. During the warmer months, the Sun is higher in the sky, stays above the horizon for longer, and its rays are ...
Why are seasons different?
One common misconception that students have about seasons is that seasons are due to how close or far the Earth is to the sun. The changing position of the Earth’s tilt is the reason for the differences in temperature and length of daylight that distinguish the seasons. When the Northern Hemisphere of the Earth is leaning toward the sun, it receives direct sunlight. The warmth of direct rays causes spring and then summer in that part of the globe. When the Northern Hemisphere of the Earth is leaning away from the sun, it receives more indirect sunlight. The cooling effects of more indirect sunlight cause autumn and winter. Because of the Earth’s approximately 23.5º tilt, the seasons in the Northern and Southern Hemispheres are reversed, about six months apart from each other.
How to explain the axis of the Earth?
Then explain the following to students: The Earth rotates on an axis that is tilted. In other words, our planet never stands upright—it is always leaning to the side. The direction of this lean does not change significantly over the course of a year, but it does shift gradually over millennia. As the Earth travels along its orbit, it sometimes leans toward the sun and sometimes away from the sun. Display the diagram “Seasons” for students, and point to the parts of the diagram as you explain the following: If you live in the Northern Hemisphere, you live on the part of the Earth that is north of the Equator. When the Northern Hemisphere is tilted toward the sun, you experience summer. When the Northern Hemisphere is tilted away from the sun, you experience winter. Ask: How would this change if you lived in the Southern Hemisphere? (The opposite would happen. When the Earth's axis is tilted toward the sun for the Northern Hemisphere, the people in the Northern Hemisphere experience summer, while at the same time, the Southern Hemisphere is tilted away from the sun and the people there experience winter. When the Northern Hemisphere experiences winter, the Southern Hemisphere experiences summer.)
What hemisphere is the floor in?
Ask students to imagine that the floor is the Northern Hemisphere of the Earth. In the winter, the North Pole of the Earth is pointing away from the sun, so the sun appears farther south in the sky to us. Have the student hold the sun closer to the floor.
What happens when the Northern Hemisphere is tilted toward the Sun?
When the Northern Hemisphere is tilted toward the sun, you experience summer. When the Northern Hemisphere is tilted away from ...
How to explain the Earth's orbit around the Sun?
Explain that as Earth orbits the sun, it rotates on its axis, and the axis is always pointed in the same direction. Have the students representing the Earth and sun in each group stand approximately 5-7 feet apart.
Why do we have seasons on other planets?
Remind students that the two reasons seasons occur are the tilt of a planet’s axis and its orbit around the sun.
What is the most hours of sunlight in the Northern Hemisphere?
day of the year with the most hours of sunlight, June 20 or 21 in the Northern Hemisphere and December 21 or 22 in the Southern Hemisphere.
How does the Earth's tilt affect daylight?
Over the equator, the answer is not much. If you live on or very close to the equator, your daylight would be basically within a few minutes of 12 hours the year around. Using the northern hemisphere as a reference, the daylight would lengthen/shorten during the summer/winter moving northward from the equator. The daylight difference is subtle in the tropics, but becomes extremely large in the northern latitudes. Where we live in the mid latitudes, daylight ranges from about 15 hours around the summer solstice to near nine hours close to the winter solstice. Moving to the arctic circle at 66.5 degrees north latitude, the Sun never sets from early June to early July. But around the winter solstice, the daylight only lasts slightly more than two hours. There becomes a profound difference in the length of daylight heading north of the arctic circle. Barrow, Alaska at slightly more than 71 degrees north latitude, lies just less than 300 nautical miles north of the arctic circle. Barrow sees two months of total darkness, as the Sun never rises for about a month on each side of the winter solstice. On the other hand, Barrow also has total light from mid May to early August. And what about the north pole, or 90 degrees north latitude? The Sun rises in the early evening near the spring equinox and never sets again until just after the autumnal equinox, or six months of light. Conversely, after the Sun sets in the mid morning just after the autumnal equinox, it will not be seen again until the following spring equinox, equating to six months of darkness.
What is the position of the Sun on June 21?
Near June 21st, the summer solstice, the Earth is tilted such that the Sun is positioned directly over the Tropic of Cancer at 23.5 degrees north latitude. This situates the northern hemisphere in a more direct path of the Sun's energy.
Why is the northern hemisphere hotter in January?
Instead, the seasons are caused by the Earth being tilted on its axis by an average of 23.5 degrees (Earth's tilt on its axis actually varies from near 22 degrees ...
Why is the Sun scattered before reaching the ground?
Furthermore, a large amount of the Sun's energy is scattered before reaching the ground because the energy has to travel through more of the atmosphere.
How does the Earth's orbit around the Sun work?
Here's how it works: The Earth has an elliptical orbit around our Sun. This being said, the Earth is at its closest point distance wise to the Sun in January (called the Perihelion) and the furthest in July (the Aphelion). But this distance change is not great enough to cause any substantial difference in our climate.
Which hemisphere receives the most direct sunlight?
The southern hemisphere is therefore receiving the direct sunlight, with little scattering of the sun's rays and a high sun angle producing long days. The northern hemisphere is tipped away from the Sun, producing short days and a low sun angle. What kind of effect does the earth's tilt and subsequent seasons have on our length of daylight ...
When is the equinox on Earth?
Advancing 90 days, the Earth is at the autumnal equinox on or about September 21st. As the Earth revolves around the Sun, it gets positioned such that the Sun is directly over the equator. Basically, the Sun's energy is in balance between the northern and southern hemispheres. The same holds true on the spring equinox near March 21st, as the Sun is once again directly over the equator.
Why do seasons happen?
Seasons happen because Earth's axis is tilted at an angle of about 23.4 degrees and different parts of Earth receive more solar energy than others. Earth's orbit around the Sun is elliptical. Because of Earth's axial tilt (obliquity), our planet orbits the Sun on a slant which means different areas of Earth point toward or away from ...
What is the summer month in the Northern Hemisphere?
Around the June solstice, the North Pole is tilted toward the Sun and the Northern Hemisphere gets more of the Sun's direct rays. This is why June, July and August are summer months in the Northern Hemisphere.
When is the Southern Hemisphere in the opposite direction of the Sun?
Opposite Seasons. At the same time, the Southern Hemisphere points away from the Sun, creating winter during the months of June, July and August. Summer in the Southern Hemisphere is in December, January, and February, when the South Pole is tilted toward the Sun and the Northern Hemisphere is tilted away.
Why is the temperature difference between northern and southern summers so small?
However, because there are relatively few landmasses south of the equator and oceans take more time to heat up, the temperature difference between the northern and southern summers is very small. Topics: Astronomy, Sun, Earth, Seasons, Equinox, Solstice.
Is the Earth farthest away from the Sun?
However, our planet's distance from the Sun has little effect on the onset of seasons. In fact, Earth is closest to the Sun, or at its Perihelion, around the Northern Hemisphere's winter solstice, while it is farthest away from the Sun, or at its Aphelion, around the north's summer solstice.
Does the direction of the Earth's tilt change?
The direction of Earth's tilt nearly doesn't change – the two hemispheres point toward the same position in space through the entire year. What does change, as Earth revolves around the Sun, is the position of the hemispheres in relation to the Sun – the Northern Hemisphere points toward the Sun during the northern summer and away from the Sun during the northern winter.
Does distance cause seasons?
Distance Does Not Cause Seasons. Spring, summer, fall, and winter. It is a common misconception that seasons occur because of Earth's elliptical orbit around the Sun, with winter occurring when Earth is farthest away from the Sun, and summer when it is closest to it.
When are the times and dates of the next equinoxes and solstices?
The chart shown below shows the dates and times for the equinoxes and solstices through 2020. Times listed are in Eastern Time. Subtract one hour for Central Time. (Source: U.S. Naval Observatory)
How does a flashlight work?
All the light from the flashlight is in that circle. Now slowly tilt the paper, so the circle elongates into an ellipse. All the light is still in that ellipse, but the ellipse is spread out over more paper. The density of light drops.
How far away is the North Pole from the Sun?
Since the tilt of the axis is 23 1/2 degrees, the North Pole never points directly at the Sun, but on the summer solstice it points as close as it can, and on the winter solstice as far as it can. Midway between these two times, in spring and autumn, the spin axis of the earth points 90 degrees away from the sun.
What forces are there when you try to stand an egg on end?
The underlying assumption relating to standing eggs on end is that there must exist some special gravitational balance. There are many forces acting on an egg when you try to stand it on end on a flat surface. Some people think that the gravitational pull of the Sun becomes balanced with that of the Earth to allow for this phenomenon to occur. However, the Moon exerts a much stronger gravitational effect on the Earth than the Sun, dominating the ebb and flow of the ocean tides. The Moon's effects are different at each of the equinoxes however. The most dominant force of gravity on a standing egg is the one between the Earth and the egg itself. This is determined by the weight of the egg and the force pulling the egg to the counter top.
What is the difference between sunrise and sunset?
Sunrise is defined as the instant when the leading edge of the Sun's disk becomes visible on the horizon, whereas sunset is the instant when the trailing edge of the disk disappears below the horizon. At these times, the center of the disk is already below the horizon.
Why is the Sun's disk visible in the morning?
Furthermore, atmospheric refraction (or bending) of the Sun's rays cause the Sun's disk to appear higher in the sky than it would if the Earth had no atmosphere. Thus, in the morning, the upper edge of the disk is visible for several minutes before the geometric edge of the disk reachs the horizon.
What happens when the sun is overhead?
When the sun is overhead, the light is falling straight on you, and so more light (and more heat) hit each square centimeter of the ground. When the sun is lower in the sky, the light gets more spread out over the surface of the earth, and less heat (per square centimeter) can be absorbed.
Why does the summer solstice lag?
This lag is due to the time required for ground and water to heat up.
What is the position of the sun on the day of the summer solstice?
Therefore, on the day of the summer solstice, the sun appears at its highest elevation with a noontime position that changes very little for several days before and after the summer solstice.
How many times does the equinox occur?
The Equinox (Vernal & Autumnal) There are only two times of the year when the Earth's axis is tilted neither toward nor away from the sun, resulting in a "nearly" equal amount of daylight and darkness at all latitudes.
What is the name of the event that occurs at noon?
These events are referred to as Equinoxes.The word equinox is derived from two Latin words - aequus (equal) and nox (night). At the equator, the sun is directly overhead at noon on these two equinoxes.
Why do seasons occur?
Seasons are caused by the fact that the Earth is tilted on its axis by 23.5°. The tilt's orientation with respect to space does not change during the year; thus, the Northern Hemisphere is tilted toward the sun in June and away from the sun in December, as illustrated in the graphic below.
Why do we have nearly equal hours of daylight?
The "nearly" equal hours of day and night is due to refraction of sunlight or a bending of the light's rays that causes the sun to appear above the horizon when the actual position of the sun is below the horizon .
How long is the day before the equinox?
Therefore, on the equinox and for several days before and after the equinox, the length of day will range from about 12 hours and six and one-half minutes at the equator, to 12 hours and 8 minutes at 30 degrees latitude, to 12 hours and 16 minutes at 60 degrees latitude.
How to measure the diameter of a graph paper?
Turn on the flashlight. Move the graph paper closer or farther away from the flashlight until the light on the paper forms a medium-sized, sharp circle 5 – 6 centimeters (cm) in diameter , as shown in Figure 6, below. Have a helper help you measure the distance from the edge of the graph paper to the cardboard box and write down this starting distance in your lab notebook. You will keep the graph paper at this starting distance for all testing.
How does the tilt of the axis create seasons?
How does the tilt of the axis create seasons? The tilt changes how the sunlight hits Earth at a given location. As shown in Figure 1, Earth's axis (the red line) remains fixed in space. It always points in the same direction, as Earth goes through its orbit around the Sun.
Why are slanted rays weaker than direct rays?
Slanted rays are weaker rays because they cover a larger area and heat the air and surface less than direct rays do, as shown in Figure 2, below. You can see this if you shine a flashlight on a large ball. If you point the flashlight directly at the ball, it makes a bright, circular spot on the ball; however, if your point the flashlight at the edge of the ball, the light makes a duller, more oval-looking spot on the ball. The same thing happens with Earth and the Sun—imagine the ball is Earth and the flashlight is the Sun. In this astronomy science fair project, you will investigate how tilting a surface affects how light rays hit that surface.
What is the difference between summer and winter?
When it is summer in North America, the top part of the axis (the north pole) points in the direction of the Sun, and the Sun's rays shine directly on North America; while in South America, the axis is tipped away from the Sun and the Sun's rays hit Earth on a slant. So, when it is summer in North America, it is winter in South America. When it is winter in North America, the north pole is tipped away from the Sun, and the Sun's rays hit the Earth on a slant there; meaning it is summer in South America, because the Sun's rays hit Earth more directly in that hemisphere. As for the intermediate seasons, spring and fall, these are seasons when neither the top, nor the bottom, of Earth's axis are pointed in the direction of the Sun, days and nights are of equal length, and both the top half and the bottom half of Earth get equal amounts of light.
How to draw a light on graph paper?
Use a colored pen or pencil to draw around the outline of the light on the graph paper. Draw a line from the circle and note that the graph paper is at 0 degrees for this outline (no tilt).
Why is winter in South America?
When it is winter in North America, the north pole is tipped away from the Sun, and the Sun's rays hit the Earth on a slant there; meaning it is summer in South America, because the Sun's rays hit Earth more directly in that hemisphere.
What to do if you use a camera instead of drawing around the light outlines?
If you used a camera instead of drawing around the light outlines, print out your photographs so you can analyze them.
What are the longest days of the year?
The Long and Short of It 1 The summer solstice is one of the longest days of the year in the Northern Hemisphere—and the day when there is no sunlight at the South Pole. 2 The winter solstice is one of the shortest days of the year in the Northern Hemisphere—and the day when there is no sunlight at the North Pole. 3 Daytime and nighttime on the equinoxes are not equal; this is a myth. However, within a few days of each equinox, there is a day with nearly equal daytime and nighttime. (This depends on the latitude.)
How are seasons determined?
Seasons are determined by the direction of Earth’s tilt in relation to the Sun and the angle of the Sun’s light as it strikes Earth! The equator is an imaginary line dividing Earth into the Northern and Southern Hemispheres. On two days each year, on or around March 21 and September 23, the Sun is directly above the equator.
What is the angle of the axis?
At one end of the axis is the North Pole; at the other, the South Pole. The axis is tilted at a 23.5-degree angle away from the Sun during winter in the Northern Hemisphere; it’s the opposite during summer.
Why do people decorate their houses with evergreens?
People decorated their houses with evergreen branches and lit lamps all night to ward off the darkness. Around the time of the solstice, in ancient Scandinavia, people hung mistletoe and evergreens in doorways for good luck and then gathered around bonfires to listen to singing poets.
What is the Chinese festival of the moon?
The Chinese mark the end of summer with the Mid-Autumn Moon Festival, which occurs when the Moon is at its brightest. After dark, people stroll with brightly lit lanterns, admire the full Moon, and eat moon cakes, which are pastries with a whole egg yolk in the center symbolizing the Moon. WINTER.
Why do women bathe in rivers?
In ancient times, women and girls in Sweden would bathe in a river in the belief that this would bring plenty of rain for the crops, while village people would dance around a decorated tree. Now, in late June, Swedes dance around a pole covered with greenery and flowers. AUTUMN.
Why do people watch the sky?
For centuries, people have watched the sky for the changes of season and then celebrated with colorful rituals.