Mesosphere vs. Thermosphere

Attribute	Mesosphere	Thermosphere
Altitude	50-85 km	85-600+ km
Temperature	Decreases with altitude	Increases with altitude
Composition	Mainly composed of oxygen and nitrogen	Mainly composed of atomic oxygen
Ionization	Low ionization	High ionization

Overview

The Mesosphere and Thermosphere are two layers of Earth's atmosphere that are located above the stratosphere. They both play important roles in the Earth's atmosphere and have distinct characteristics that set them apart from each other. In this article, we will compare the attributes of the Mesosphere and Thermosphere to better understand their differences and similarities.

Temperature

The Mesosphere is the layer of the atmosphere that lies above the stratosphere and below the thermosphere. It is characterized by decreasing temperatures with increasing altitude, reaching temperatures as low as -90 degrees Celsius. In contrast, the Thermosphere is the layer of the atmosphere that lies above the mesosphere and is known for its high temperatures, reaching up to 2,500 degrees Celsius due to the absorption of solar radiation.

Composition

The Mesosphere is composed mainly of oxygen and nitrogen molecules, with small amounts of other gases such as carbon dioxide and water vapor. It is also the layer where most meteors burn up upon entering the Earth's atmosphere. On the other hand, the Thermosphere is composed of a mixture of gases, including oxygen, nitrogen, and helium. It is also the layer where the auroras occur due to interactions with solar radiation.

Altitude

The Mesosphere extends from about 50 kilometers to 85 kilometers above the Earth's surface, making it the third layer of the Earth's atmosphere. It is located above the stratosphere and below the thermosphere. In contrast, the Thermosphere extends from about 85 kilometers to 600 kilometers above the Earth's surface, making it the fourth layer of the Earth's atmosphere. It is located above the mesosphere and below the exosphere.

Pressure

The Mesosphere has a pressure of about 0.1 millibars at its upper boundary, which is significantly lower than the pressure at sea level. This low pressure makes it difficult for aircraft to fly in the mesosphere. On the other hand, the Thermosphere has a pressure of about 0.001 millibars at its lower boundary, which is even lower than the pressure in the mesosphere. This extremely low pressure allows for the free movement of gas molecules and particles in the thermosphere.

Ionization

The Mesosphere is not ionized, meaning that the molecules in this layer are not charged. However, the Thermosphere is highly ionized due to the absorption of solar radiation, which causes the gas molecules to lose electrons and become charged particles. This ionization plays a crucial role in the propagation of radio waves and the formation of the ionosphere, which is important for long-distance communication.

Conclusion

In conclusion, the Mesosphere and Thermosphere are two distinct layers of Earth's atmosphere with unique characteristics that set them apart from each other. While the Mesosphere is known for its low temperatures and composition of oxygen and nitrogen, the Thermosphere is characterized by its high temperatures and ionization due to solar radiation. Understanding the differences between these two layers is essential for studying the Earth's atmosphere and its interactions with the Sun.