Layers of the Earth's Atmosphere , WEATHER, CLOUDS

Layers of the Earth's Atmosphere

The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space.
1) The troposphere is the first layer above the surface and contains half of the Earth's atmosphere. Weather occurs in this layer.
2) Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun.
3) Meteors or rock fragments burn up in the mesosphere.
4) The thermosphere is a layer with auroras. It is also where the space shuttle orbits.
5) The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere.

The Ionosphere

Scientists call the ionosphere an extension of the thermosphere. So technically, the ionosphere is not another atmospheric layer. The ionosphere represents less than 0.1% of the total mass of the Earth's atmosphere. Even though it is such a small part, it is extremely important! The upper atmosphere is ionized by solar radiation. That means the Sun's energy is so strong at this level, that it breaks apart molecules. So there ends up being electrons floating around and molecules which have lost or gained electrons. When the Sun is active, more and more ionization happens!

Weather

Weather is the state of the atmosphere at a given time and place. Most weather takes place in the troposphere, the lowest layer of the atmosphere.
Weather is measured and described in a variety of ways by meteorologists, scientists who study and predict weather. Air temperature and pressure, the amount and type of precipitation, the strength and direction of wind, and the types of clouds are all described in a weather report.
Weather changes each day because the air in our atmosphere is always moving, distributing energy from the Sun. In most places in the world, the types of weather events also vary throughout the year as seasons change.

Clouds

Clouds can come in all sizes and shapes, and can form near the ground or high in the atmosphere. Clouds are groups of tiny water droplets or ice crystals in the sky and are formed by different processes. They can make different kinds of precipitation depending on the atmosphere's temperature.
Cloud types are classified by height and appearance. The shape depends on the way the air moves around the cloud. If air moves horizontally, clouds form spread-out layers. Clouds grow upward if air is moving vertically near the cloud.
At any given time, clouds cover about 50% of the Earth. We would not have rain, thunderstorms, rainbows, or snow without clouds. Clouds make up some of the atmospheric optics we can see in the sky. The atmosphere would be boring if the sky was always clear!
Did you know that Earth is not the only planet with clouds? Other planets, like Venus, Mars, Jupiter, Neptune, Uranus, and Saturn, have clouds too!