Everyday Science Mcqs Archives | Page 143 of 191

The mesosphere is a layer within the Earth’s atmosphere that extends from about 50 kilometres height (above the stratosphere) and about 90 kilometres (below the thermosphere).
There are 5 main layers within the atmosphere.
1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere
5. Exosphere
1. Troposphere:
The troposphere is the lowest layer of the atmosphere. most of the weather takes place in this layer. Most thunderstorms don’t go much above the top of the troposphere (about 10 km).The troposphere is bounded above by the tropopause, a boundary marked as the point where the temperature stops decreasing with height and becomes constant with height.
2. Stratosphere:
The stratosphere is the layer above the troposphere. The main impact the stratosphere has on weather is that its stable air prevents large storms from extending much beyond the tropopause.The stratosphere is bounded above by the stratopause, where the atmosphere again becomes isothermal. The average height of the stratopause is about 50 km, or 31 miles.The layer above the stratosphere is the mesosphere.
3. Mesosphere:
The mesosphere is the middle layer in the atmosphere. temperature in the mesosphere decreases with height. At the top of the mesosphere, air temperature reaches its coldest value, around -90 degrees Celsius (or -130 degrees Fahrenheit).the air is extremely thin at this level. Over 99.9 percent of the atmosphere’s mass lies below the mesosphere.The mesosphere is bounded above by the mesopause. The average height of the mesopause is about 85 km (53 miles), where the atmosphere again becomes isothermal.
4. Thermosphere:
The thermosphere is a warm layer above the mesosphere. In this layer, there is a significant temperature inversion. The few molecules that are present in the thermosphere receive extraordinary amounts of energy from the sun, causing the layer to warm.here is no well defined boundary between the thermosphere and the exosphere.The exosphere is the region where molecules from the atmosphere can overcome the pull of gravity and escape into outer space. The atmosphere slowly diffuses into the viod of space. The exosphere usually begins about 500 km up.
Thanks Kashif Ashraf for update