Layers of the atmosphere

• The Troposphere. This is the lowest part of the atmosphere – the part we live in.
• The Stratosphere. This extends upwards from the tropopause to about 50 km.
• The Mesosphere. The region above the stratosphere is called the mesosphere.
• The Thermosphere and Ionosphere.
• The Exosphere.
• The Magnetosphere.

In the upper thermosphere, atomic oxygen (O), atomic nitrogen (N), and helium (He) are the main components of air. Much of the X-ray and UV radiation from the Sun is absorbed in the thermosphere.

Earth’s atmosphere has five major and several secondary layers. From lowest to highest, the major layers are the troposphere, stratosphere, mesosphere, thermosphere and exosphere. Troposphere.

The mesosphere-lower thermosphere (MLT) is defined as the region of the atmosphere between about 60 and 110 km in altitude. The MLT is dominated by the effects of atmospheric waves, including planetary waves, tides and gravity waves. The source regions for these waves are lower in the atmosphere.

troposphere
The troposphere is the lowest layer and exosphere is the highest or topmost layer.

The troposphere is the lowest layer of our atmosphere. Starting at ground level, it extends upward to about 10 km (6.2 miles or about 33,000 feet) above sea level. We humans live in the troposphere, and nearly all weather occurs in this lowest layer. Most clouds appear here, mainly because 99% of the water vapor in the atmosphere is found in

Warm air advection and moisture advection near the surface will cause the low levels of the atmosphere to become increasingly unstable. Air expands and becomes less dense by either warming or adding moisture to the air. If both of these take place at the same time, such as the advection of mT air, the atmosphere will rapidly become unstable.

The majority of the mass of the entire atmosphere is contained in the troposphere—between approximately 75 and 80 percent. Most of the water vapor in the atmosphere, along with dust and ash particles, are found in the troposphere—explaining why most of Earth’s clouds are located in this layer.

The stratosphere is nearly cloud- and weather-free, but polar stratospheric clouds are sometimes present in its lowest, coldest altitudes. It’s also the highest part of the atmosphere that jet planes can reach.