41 Atmosphere and Climate-Low

Atmosphere and Climate Written by Karen de Seve

《大气与气候》Karen de Seve著

Introduction Look up at the sky. There's a very thin shield around Earth that you can't see. It's called the atmosphere. It contains the air we breathe and our weather. The shield protects us from the harmful rays of the Sun. It helps keep our planet warm. It makes life on Earth possible. In this book, you will learn about Earth's atmosphere. You will learn about weather over short and long periods of time. You'll also learn what makes up the atmosphere and how it is changing.

抬头看看天空。 地球周围有一个非常薄的防护罩，你看不到。 它叫做大气。 它包含我们呼吸的空气和我们的天气。 这个盾牌保护我们不受太阳有害射线的伤害。 它帮助我们的星球保持温暖。 它使地球上的生命成为可能。 在这本书中，你将了解地球的大气层。 你将学习短时间和长时间的天气。 你还将了解大气的组成以及它是如何变化的。

Earth's Invisible Shield The atmosphere is like a blanket. It protects and warms Earth's surface. It rises more than 700 kilometers (430 mi.) above Earth's surface. All the gases needed for life are in the atmosphere. The two main ones are nitrogen and oxygen. There are also smaller amounts of argon, carbon dioxide (CO2), and water vapor We need oxygen the most. Without oxygen, life as we know it could not exist.

地球的隐形盾牌大气层就像一张毯子。 它保护和温暖地球表面。 它高出地球表面700多公里(430英里)。 生命所需的所有气体都在大气中。 两种主要的是氮和氧。 还有少量的氩气、二氧化碳和水蒸气。我们最需要氧气。 没有氧气，我们所知道的生命就不可能存在。

Gases are made up of small particles called molecules. Gravity pulls the molecules toward Earth and packs them together. This blanket of gas molecules creates air pressure. The air pressure at the bottom of the atmosphere is fairly high. The air pressure farther up in the atmosphere is much, much lower.

气体是由叫做分子的小颗粒组成的。 重力将分子拉向地球并将它们聚集在一起。 这层气体分子形成了空气压力。 大气底部的气压相当高。 大气中较高处的气压要低得多。

You do not usually feel air pressure. The pressure is the same inside and outside your body. But when you take off in an airplane or drive up a mountain, you go higher in the atmosphere. The air pressure is less there. As the air pressure outside drops, the air pressure inside your ears stays the same. The air pushes out from your ears and makes a popping sound. Do You Know? Air pressure drops as you climb higher. If you climb high enough, the air is very spread out. You will need extra oxygen in order to breathe.

你通常感觉不到气压。 身体内外的压力是一样的。 但是当你乘飞机起飞或开车上山时，你在大气中飞得更高。 那里的气压较小。 当外面的气压下降时，你耳朵里的气压保持不变。 空气从你的耳朵里挤出来，发出砰的一声。 你知道吗?你爬得越高，气压就越低。 如果你爬得足够高，空气是非常分散的。 你需要额外的氧气才能呼吸。

Layers of Atmosphere The atmosphere around Earth is divided into five layers. We live in the lowest layer— the troposphere. Earth's weather forms and changes in this layer. The stratosphere is the next layer. In this layer is the ozone layer. It protects us from the Sun's harmful rays. When people release certain gases at Earth's surface, the gases can float up and break down ozone. Then the ozone cannot absorb harmful rays as well. The mesosphere is the middle layer in which most meteors burn up. Spacecraft orbit in the thermosphere. The exosphere is the outermost layer.

地球周围的大气层分为五层。 我们生活在最低的一层——对流层。 地球的天气在这一层形成和变化。 平流层是下一层。 这一层是臭氧层。 它保护我们免受太阳有害射线的伤害。 当人们在地球表面释放某些气体时，这些气体会漂浮起来，破坏臭氧。 然后臭氧也不能吸收有害射线。 中间层是大多数流星燃烧的中间层。 航天器在热层轨道上运行。 外层是最外层。