章节大纲

  • 常规

    全部折叠 展开全部

  • 平流层

    Lesson
    ::经验教训

     

    A jet airplane flying above fluffy clouds in the stratosphere.
     

    Can we take a field trip to the stratosphere?
    ::我们能去平流层实地考察吗?

    Sure we can! If you've ever flown on a jet airplane, you've been in the stratosphere. Airplanes fly in the stratosphere, because there is less friction. They get better gas mileage and so costs are lower. There is also less turbulence, so passengers are happier. Can you identify the bottom of the stratosphere in the photo? It's where the   begin. Remember that all   is in the  .
    ::当然可以!如果你曾经坐过喷气飞机,你已经坐过平流层。 飞机在平流层中飞行, 因为摩擦较少。 它们得到的气体里程更好, 成本也较低。 气流也更少, 乘客也更快乐。 您可以在照片中识别平流层底部吗? 起点是这里。 记住, 所有的都在这里 。

    Stratosphere
    ::平流层

    The  stratosphere  is the layer above the troposphere. The layer rises from the tropopause, at 12 kilometers (7 miles) above the Earth’s surface to about 50 kilometers (31 miles).
    ::平流层是对流层上方的层。 层从地表上方12公里(7英里)上升至约50公里(31英里 ) , 从地表上方12公里(7英里 ) 上升至约50公里(31英里 ) 。

    Temperature in the Stratosphere
    ::平流层中的温度

    Air   in the stratosphere increases with  altitude . Why? The stratosphere absorbs a great deal of the  energy  that comes from the   and much of this absorption occurs in the upper layers of the stratosphere. Therefore, the stratosphere is warmest at its highest point. The air at the bottom of the stratosphere is cold. The cold air is dense, so it doesn’t rise. As a result, there is little mixing of air in this layer.
    ::平流层中的空气随着高度的增加而增加。 为什么?平流层吸收了大量来自这种吸收的能量,而这种吸收大多发生在平流层的上层。 因此,平流层在最高点是最温暖的。平流层底部的空气是寒冷的。 寒冷的空气是稠密的,因此不会上升。 结果,这一层的空气很少混合。

    The Ozone Layer
    ::臭氧层臭氧层

    The stratosphere contains a layer of  ozone  gas.  Ozone  consists of three oxygen atoms (O 3 ). The  ozone layer  is in the stratosphere. Ozone in the layer absorbs high-energy ultraviolet (UV) radiation. UV radiation splits the ozone  molecule  ( Figure  ). The split creates an oxygen molecule (O 2 ) and an oxygen  atom  (O). This split releases  heat  that warms the upper layers of the stratosphere. The ozone layer also protects living things on Earth’s surface from harmful UV radiation.
    ::平流层含有一层臭氧层,臭氧由三个氧原子组成(O3),臭氧层在平流层中,臭氧层吸收高能紫外线辐射(UV),紫外线辐射分裂臭氧分子(图)。分裂产生氧分子(O2)和氧原子(O)。这种分裂释放热能,使平流层上层温暖。臭氧层还保护地球表面的生物免受有害的紫外线辐射。

    Graphic depicting the ozone layer's role in absorbing UV radiation and its effects on Earth.
     
    How does the ozone layer protect Earth’s surface from UV light?

    Stratopause
    ::Statatopause 台式

    At the top of the stratosphere is a thin layer called the stratopause. It acts as a boundary between the stratosphere and the  .
    ::平流层的顶端是一层薄层,叫做斜面层,是平流层与平流层之间的界线。

    Summary
    ::摘要

    • There is little mixing between the troposphere and the stratosphere.
      ::对流层与平流层之间几乎没有混合。
    • Ozone gas protects life on Earth from harmful UV light.
      ::臭氧气体保护地球上的生命免受有害的紫外线照射。
    • The ozone layer is in the stratosphere. It has a higher concentration of ozone than the rest of the atmosphere.
      ::臭氧层在平流层中,其臭氧浓度高于大气其他部分。

    Review
    ::回顾

    1. Why doesn't air mix much in the stratosphere?
      ::为什么平流层的空气不常混合?
    1. What is the ozone layer? Why is it important?
      ::臭氧层是什么?它为什么重要?
    1. Why does air temperature increase with height in the stratosphere?
      ::为什么空气温度随着平流层的高度而上升?

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. Where is the stratosphere located?
      ::平流层在哪里?
    1. How is ozone, the O3 molecule, created?
      ::臭氧,O3分子是如何生成的?
    1. By what process does this ozone molecule become stable?
      ::这种臭氧分子在什么过程中变得稳定?
    1. Why is ozone important?
      ::为什么臭氧很重要?