季节

 

Do you like the seasons?
::你喜欢季节吗?

Do you live in a place with well-defined seasons? Do you appreciate the change of the seasons? In other words, are you happy that Earth's  axis  is tilted?
::你们是否居住在一个有明确季节的地方?你们感谢季节的变化吗?换句话说,你们对地球轴倾斜感到高兴吗?

Earth’s Seasons
::地球季节

Some people think that Earth is closer to the   in the summer and farther away from the Sun in the the winter. But that's not true! Why can't that be true? Because when it's summer in one  hemisphere , it's winter in the other. So what does cause the seasons? The seasons are caused by the 23.5° tilt of Earth’s axis. One hemisphere points more directly toward the Sun than the other hemisphere. As Earth orbits the Sun, the tilt of Earth's axis stays lined up with the North  Star .
::一些人认为地球更接近夏季,更远离冬季的太阳。 但事实并非如此! 为什么不能这样呢? 因为当夏天在一个半球,冬天在另一个半球,是什么原因导致季节?季节是由地球轴的23.5度倾斜造成的。一个半球比另一个半球更直接地指向太阳。当地球绕太阳运行时,地球轴的倾斜一直与北星站在一起。

Solstice  refers to the position of the Sun when it is closest to one of the poles. At  equinox , the Sun is directly over the  equator .
::太阳离极最近时,太阳的位置指太阳的位置。在五角星,太阳直接在赤道上空。

Northern Hemisphere Summer
::北半球夏季

During summer in the  Northern Hemisphere , the North Pole is tilted toward the Sun. The Sun's rays strike the Northern Hemisphere more directly ( Figure   ). The region gets a lot of sunlight.  Summer solstice  is June 21 or 22. At that time, the Sun's rays hit directly at the Tropic of Cancer (23.5°N). This is the farthest north that the Sun will be directly overhead. Summer solstice in the Northern Hemisphere is  winter solstice  in the  Southern Hemisphere .
::在北半球的夏季,北极向太阳倾斜。太阳的射线更直接地照射北半球(图 ) 。 该区域获得大量的阳光。 夏季太阳是6月21日或22日。 当时,太阳的射线直接照射到癌症热带(北纬23.5度 ) 。 这是太阳将直接飞越的最远的北纬地区。 北半球的夏季太阳是南半球的冬季太阳。

 

Northern Hemisphere Winter
::北半球冬季

Winter solstice  for the Northern Hemisphere happens on December 21 or 22. At that time, the Sun's rays hit directly at the Tropic of Capricorn (23.5°S). When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere. The North Pole of Earth's axis points away from the Sun ( Figure   ). Light from the Sun is spread out over a larger area. With fewer daylight hours in winter, there is also less time for the Sun to warm the area.
::北半球的冬季休眠时间是12月21日或22日,当时太阳的射线直接击中了摩角的热带(23.5°S)。当北半球的冬季时,是南半球的夏季。地球轴点的北极远离太阳(图)。太阳的光散布在更大的区域。冬天的日光时间较短,太阳温暖该地区的时间也更少。

 

Equinox
::春分

Equinox  comes halfway between the two solstices. At equinoxes, the Sun's rays shine most directly at the equator ( Figure   ). The daylight and nighttime hours in the Northern and Southern Hemispheres are nearly equal on an equinox. The autumnal, or fall, equinox happens on September 22 or 23. The vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere.
::春分介于两个休眠期的中间。 在春分期,太阳的射线最直接地照耀赤道(图 ) 。 北半球和南半球的日间和夜间时间几乎相等于春分。 秋分或秋分发生在9月22日或23日。 春分或春分发生在北半球的3月21日或22日。

 

Summary
::摘要

• Earth has seasons because of the (23.5°) tilt of its axis of rotation.
  ::由于旋转轴倾斜(23.5度),地球有季节。

• In the Northern Hemisphere, at summer solstice the Sun is closest to the North Pole (around June 22). At winter solstice, the Sun is closest to the South Pole (around December 22). In the Southern Hemisphere, the names are changed.
  ::在北半球,夏季定时太阳最接近北极(大约6月22日),冬季定时太阳最接近南极(大约12月22日)。在南半球,名称改变。

• At equinox, the Sun is directly over the equator. Autumnal equinox is around September 22. Spring equinox is around March 22.
  ::在春分时,太阳直接在赤道上空。秋分在9月22日左右。春分在3月22日左右。秋分在9月22日左右。春分在3月22日左右。

Review
::回顾

1. Imagine that it is summer solstice in the Northern Hemisphere. What is the date, and where is the Sun? What is happening in the Southern Hemisphere?
   ::想象一下,这是北半球的夏令营。是什么日期,太阳在哪里?南半球发生什么了?

1. Describe why Earth has seasons.
   ::描述为什么地球有季节。

1. What are equinoxes? When do they come?
   ::春分是什么 什么时候来