Why We Have Seasons Why We Have Seasons Seasons are produced by the inclination of the earth’s axis ofrotation, with the yearly revolution around the sun. During the earth’syearly revolution around the sun, the northern and southern hemispheresalternate their incline towards and away from the sun. This unequalheating of the earth’s surface causes the weather to change inapproximately three-month periods. When the Northern Hemisphere isinclined toward the sun from about March 21st to September 23rd the earthssurface is heated causing the seasons of spring and summer to occur.Meanwhile in the Southern Hemisphere the effects of fall and winter occur.The first three months are the season of spring and the second three monthsare the months of summer. The vernal equinox occurs when the sun is directly over the equatorand it complies with the first day of spring.
It also means that the sunis an equal distance from the north and south poles. At this time bothhemispheres have the same amount of sun as the sun makes its way north.Before the vernal equinox the sun hits the northern surface at an angleinstead of hitting it directly. By hitting the earth’s surface at an anglethere is not as much radiation warming the surface. As the earth rotatesand the sun moves further north the temperature increases and the weatherturns warmer. During the three months of spring the sun continues to movenorth and warming the earth more efficiently.
At around June 21st the sunis directly facing the tropic of cancer. At this time the movement northcomes to a halt and the earth’s surface is at its warmest point, the summersolstice. It is also known as the longest day of the year when the earthis furthest away from the sun. During the winter the sun is actuallycloser to the sun, but it gets less heat because of the unstable amount ofradiation. Throughout the spring months the sun is slowly making its wayto its maximum power on the first day of summer. The earth stays warmerduring the summer months even when the sun is moving south because it ismoving downward at a slower pace than its speed moving up to the north.The Southern Hemisphere has the exact opposite seasons.
At the time of thevernal equinox or northern spring it is the beginning of fall. As thesummer solstice makes its decent into fall in the north the SouthernHemisphere is beginning their spring season. It can be a slow andunpredictable process, the weather can be calm one year and vicious thenext. Inside the Arctic and Antarctic circles the weather is dramaticallydifferent then from the rest of the earth’s surface. During the summersolstice in the Northern Hemisphere the North Pole will receive 24 hours ofdaylight.
At its greatest altitude in the sky the sun will be visible fora full 24 hours. During these 24 hours the sun will appear in the samespot for a few days. Slowly the sun will begin to set for a few minutes ata time. So there are a few months where the days will increase in lengththen they will start to decrease in length. During the winter there are afew days in which the sun never rises, causing darkness for days at a time.In the South Pole the Antarctic Circle gets the same seasonal change at theopposite time as the north.
During the few days when there is onlysunlight in the Arctic Circle there will be a few days of only darkness inthe Antarctic Circle. The angle of the earth and its rotation preventeither of the poles from getting hit directly be the sun. The sun will hitit at an angle that changes so slightly during the summer solstice that thepoles will have only sunlight for 24 hours at a time. The season on earth are caused by the earth’s angle of rotationaround the sun. It is estimated that the sun will be at its highest pointduring the day of June 21st, however it is not exact.
It is hard topredict the weather for a certian season because each year promisessomething new. All we can do is predict what will happen. With our newtechnology we are becoming more accurate, but the weather has a mind of itsown. The spring is known to start the warming of the earth until the sunis at its greatest point of radiation. From that point it decreases slowlyinto the summer months. Bibliography I love me Science.