The Syrian airfield prepare for reception of military aircraft of China
The latest news about fast emergence in borders of Syria of navy of China encouraged Syrians and res[...]
The Atmosphere’s Layers
The atmosphere is not the same all the way up from the ground. It is divided into four layers: the troposphere, stratosphere, mesosphere, and thermosphere.
The lowest layer is the troposphere. It extends from Earth’s surface up to a height of about 4 miles (6.4 kilometers) at the poles and 11 miles (17.7 kilometers) at the equator. Most weather and clouds occur in the troposphere. Temperature falls with height, dropping to about -112°F (-80°C) at the top. Clouds are produced by water vapor rising into the colder air and changing into water droplets or ice crystals.
Jet streams are fast air currents found near the top of the troposphere. They are studied by meteorologists, because they affect the weather below them. The jet streams’ winds blow from west to east. The wind speed is normally 35 to 75 miles per hour (56 to 121 kilometers per hour), but speeds of more than 250 miles per hour (402 kilometers per hour) have been recorded. An airliner using the jet stream to fly eastward can fly faster without burning any more fuel.
The layer above the troposphere is the stratosphere. The stratosphere is drier and less dense than the layer below it. It goes up to a height of about 31 miles (50 kilometers) above Earth’s surface and contains the ozone layer. Ozone is a type of oxygen with three atoms instead of the usual two. This gas soaks up harmful ultra-violet radiation from the Sun. Because of this, the temperature rises with height in the stratosphere, up to about 32°F (0°C) at the top.
The next layer is the mesosphere. It goes from about 31 miles (50 kilometers) above Earth’s surface up to about 53 miles (85 kilometers). Less is known
О This diagram shows the layers of the atmosphere and the exosphere. Some satellites orbit Earth in the exosphere; others are out in space.
about the mesosphere than the lower layers because it is too high for most aircraft to fly in and too low for most spacecraft to orbit in. Temperature falls yet again in the mesosphere, down to about -148°F (-100°C).