In December, when the Northern Hemisphere is tilted away from the sun, with fewer hours of daylight. Seasons have an enormous influence on vegetation and plant growth. Winter typically has cold weather, little daylight, and limited plant growth. In spring, plants sprout , tree leaves unfurl , and flowers blossom. Summer is the warmest time of the year and has the most daylight, so plants grow quickly. In autumn, temperatures drop, and many trees lose their leaves.
The four-season year is typical only in the mid-latitudes. The mid-latitudes are places that are neither near the poles nor near the Equator. The farther north you go, the bigger the differences in the seasons.
Helsinki, Finland, sees In mid-December, however, it is light for less than 6 hours. Athens, Greece, in southern Europe, has a smaller variation. It has Places near the Equator experience little seasonal variation. They have about the same amount of daylight and darkness throughout the year. These places remain warm year-round. Near the Equator, regions typically have alternating rainy and dry seasons. Polar regions experience seasonal variation, although they are generally colder than other places on Earth.
Near the poles, the amount of daylight changes dramatically between summer and winter. In Barrow, Alaska, the northernmost city in the U. The city is in total darkness between mid-November and January. Seasons in Alaska Sometimes, seasons are determined by both natural and man-made activity. In the U. If a media asset is downloadable, a download button appears in the corner of the media viewer.
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The northern hemisphere experiences summer during the months of June, July, and August because it is tilted toward the sun and receives the most direct sunlight. Inversely, summer for the southern hemisphere takes place during the months of December, January, and February because that is when it receives the most direct sunlight.
Did you know that the earth is approximately 3. Learn more about the relationship between the earth and the sun with these resources.
Students use oranges to investigate the effects of changing a 3-D surface to a 2-D surface. They then examine the distortions of different map projections while comparing land and ocean to its representation on a globe. Join our community of educators and receive the latest information on National Geographic's resources for you and your students.
Skip to content. Twitter Facebook Pinterest Google Classroom. Ask: Does the sun shine more directly on the person on the top half of the Earth, or the person on the bottom half?
The person in the Southern Hemisphere is receiving more direct sunlight, so it is warmer there and is the summer season. Is the sun brighter or more concentrated for the person in summer or the person in winter? Ask: When it is winter on the top north of the Earth, what season is it on the bottom south of the Earth? In the summer, the angle of the sun is more directly over us, and larger, providing more direct solar radiation and making it warmer. In the winter, the angle of the sun is smaller and we receive less direct solar radiation, so it is colder.
Informal Assessment Ask students to orally explain how the interaction between the sun and Earth affects seasons here on Earth, and what happens with the sun's rays during the different seasons. Extending the Learning Explain to students that every planet in our solar system has seasons. Learning Objectives Students will: explain the relationship between the sun and Earth describe how the tilt and position of the Earth affects the seasons explain differences in direct and indirect sunlight.
Teaching Approach Learning-for-use. Resources Provided The resources are also available at the top of the page. Grouping Large-group instruction Small-group instruction. Background Information One common misconception that students have about seasons is that seasons are due to how close or far the Earth is to the sun.
Prior Knowledge the Earth orbits the sun and rotates on its own axis. Recommended Prior Activities None. Vocabulary acute angle. Northern Hemisphere. North Pole. Southern Hemisphere. South Pole. Tip Going Green To make this activity more "green," use round fruit instead of polystyrene foam balls. Modification For advanced students, introduce the concepts of the winter solstice, summer solstice, autumnal equinox, and vernal equinox.
Modification In Step 4, address any student misconceptions about direct versus indirect sunlight. It is winter in December in the Northern Hemisphere, because that is when it is the South Pole's turn to be tilted toward the Sun.
And, believe it or not, aphelion when Earth is farthest from the Sun occurs in July, and perihelion when we are closest occurs in January. For those of us who live in the Northern Hemisphere where it's summer in July and winter in January, that seems backwards, doesn't it?
That just goes to prove that Earth's distance from the Sun is not the cause of the seasons. What Causes the Seasons? The Short Answer:. Earth's tilted axis causes the seasons. At these times, the center of the disk is already below the horizon. 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. Similarly, in the evening, the upper edge of the disk disappears several minutes after the geometric disk has passed below the horizon. For observers within a couple of degrees of the equator, the period from sunrise to sunset is always several minutes longer than the night.
At higher latitudes in the Northern Hemisphere, the date of equal day and night occurs before the March equinox. Daytime continues to be longer than nighttime until after the September equinox. In the Southern Hemisphere, the dates of equal day and night occur before the September equinox and after the March equinox. The chart shown below shows the dates and times for the equinoxes and solstices through Times listed are in Eastern Time.
Subtract one hour for Central Time. Source: U. Naval Observatory. The answer is YES. However, you can stand an egg on end, with a large amount of patience, on any day of the year. This idea seems to pop up every year around the equinox. The thought that an egg can only stand on end on the spring equinox due to gravitational forces of the sun being aligned with the earth sounds like science, but it isn't.
According to Chinese tradition, an egg can be made to stand on end at the precise moment winter ends and spring begins. But, the Chinese calendar had this transition occurring at a variable time each year, determined partly by the Chinese lunar month, usually in early February. More recently, this thought became fixed to the time of the spring equinox.
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