Facts about Earth and the universe

Where Is the Tropopause?

 
German Portillo
By German Portillo. December 30, 2024
Where Is the Tropopause?

We have already explained the different levels of Earth's atmosphere at thedailyECO, but the expanse which divides our planet from the rest of our solar system is vast. This means that smaller sub-layers are often required to better understand some of the liminal areas of the atmosphere. Each layer is neither completely isolated nor do they have distinct boundaries. This leads to transition zones called ‘pauses’ in which the physical properties of the layers change from one type to another. One of the most important pauses is the tropopause, located between the troposphere and the stratosphere. We learn more about its characteristics and altitude by asking where is the tropopause?

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Contents
  1. Where is the tropopause located in the atmosphere?
  2. Characteristics of the tropopause
  3. Function of the tropopause
  4. Other pauses in the layers of the atmosphere

Where is the tropopause located in the atmosphere?

The tropopause is a boundary layer in the atmosphere that separates the troposphere from the stratosphere. The troposphere is the part of our atmosphere where most meteorological phenomena occur, whereas the stratosphere is a more stable and less turbulent region. It is found at different altitudes depending on latitude and weather conditions. For example:

  • Near the equator: it is usually between 16 and 18 kilometres high above sea level
  • Polar regions: it can be located at about 8 to 10 kilometres above sea level.

This pause zone acts as a barrier limiting the exchange of air and chemicals between the troposphere and the stratosphere. It is known to be a thermal transition region. In the troposphere, the temperature decreases with height, but in the tropopause it stabilizes or may even begin to increase slightly as you enter the stratosphere.

Discover more with our article asking what is the troposphere?

Where Is the Tropopause? - Where is the tropopause located in the atmosphere?

Characteristics of the tropopause

The tropopause has several characteristics that make it unique among the layers of the atmosphere. Some of the most important characteristics of the tropopause are the following:

  • Constant temperature: unlike the troposphere itself where temperature decreases with height, temperature variations stop in the tropopause. The temperature in this transitional zone remains practically constant, marking a thermal boundary between the troposphere and the stratosphere.
  • Variable altitude: many may ask what altitude is the tropopause, but its height is not fixed. Its altitude depends on factors such as latitude and weather conditions. At the equator, the tropopause is higher due to the greater solar energy received, while at the poles it is lower. It can also vary slightly depending on the season of the year.
  • Barrier function: the tropopause limits the vertical movement of air masses. This means that most of the water vapor, aerosols and other chemical compounds from the troposphere do not reach the stratosphere. This is important to maintain differences in the chemical composition of both layers.
  • Wind shear region: winds are usually stronger in the tropopause and can change direction or speed, giving rise to phenomena such as jet streams. These are crucial for global atmospheric circulation and the formation of weather systems. Discover more about these phenomena with our article asking what is wind shear and its effects?
  • Climate-related variations: global warming and climate change can affect the altitude and stability of the tropopause. For example, an increase in the temperature of the troposphere can raise the height of this layer, in turn influencing global weather patterns.

Function of the tropopause

The tropopause plays a fundamental role in the balance and functioning of the Earth's atmosphere, acting as a dynamic boundary between the troposphere and the stratosphere. In creating this transitional zone, the tropopause carries out the following functions:

  • Regulation of energy and matter exchange: the tropopause limits the exchange of heat, gases and particles between the troposphere and the stratosphere. For example, water vapor is abundant in the troposphere, but it occurs at very low levels in the stratosphere due to the tropopause barrier.
  • Climate and weather control: this layer marks the upper limit of meteorological processes, as most clouds and storms do not manage to exceed the transitional zone.
  • Influence on global circulation: jet streams are located at the tropopause. These currents act as a kind of conveyor belt that moves high and low pressure systems, affecting the distribution of heat and humidity on the planet.
  • Protection from radiation and stratospheric compounds: the tropopause helps prevent chemicals from the stratosphere, such as ozone, from easily entering the troposphere. We learn more about what is tropospheric ozone in our related guide.
  • Cushioning the impact of external phenomena: the tropopause also helps to moderate the impact of external phenomena such as volcanic eruptions and solar events. For example, when an eruption releases gases or particles into the atmosphere, the tropopause can limit the vertical dispersion of these substances, concentrating them in the troposphere or stratosphere depending on their height.

To better understand the nature of some of these phenomena, we ask what causes a volcano to erupt?

Where Is the Tropopause? - Function of the tropopause

Other pauses in the layers of the atmosphere

In addition to the tropopause, the Earth's atmosphere has other pauses that mark the boundaries between its different layers. These pauses perform similar functions to the tropopause, serving as transitions between regions with different physical properties. We find out what are the other pauses of the atmosphere:

  • Stratopause: located between the stratosphere and the mesosphere at approximately 50 kilometres (31 mi) altitude, it marks the end of the temperature increase that occurs in the stratosphere due to the absorption of ultraviolet radiation by ozone. It is a relatively stable layer, with temperatures peaking in this region at around 0°C. The stratopause acts as a barrier separating the stratosphere where ozone dominates, from the mesosphere, the latter being a cooler and less dense layer. It also regulates the flow of heat and energy between these two layers.
  • Mesopause: located between the mesosphere and the thermosphere at an altitude of about 80-85 kilometres, it is the coldest region of the atmosphere, with temperatures that can drop to -90°C or less. As you travel through this pause, the temperature stops decreasing with height and begins to increase upon entering the thermosphere. The mesopause limits heat loss to space and helps contain phenomena such as atmospheric waves and turbulence.
  • Thermopause: located between the thermosphere and the exosphere at an altitude of around 500 to 1,000 kilometres, depending on solar activity. The temperature in this zone stops increasing with height and reaches extremely high values due to the absorption of solar radiation by the gases present. Due to the low density of the air, the heat transferred to objects is minimal. It marks the transition to the exosphere where gas molecules are so scarce that they no longer behave as a continuous fluid.

Discover more about how the Earth's atmosphere affects our planet with our article asking what is general atmospheric circulation?

If you want to read similar articles to Where Is the Tropopause?, we recommend you visit our Facts about Earth and the universe category.

Bibliography
  • Sáenz García, Guadalupe. 2016. Study and characterization of the tropopause: thermal, dynamic and chemical.
    https://dehesa.unex.es/handle/10662/4153#
  • Vertical structure of the atmosphere. Educaplus.
    https://www.educaplus.org/climatic/01_atm_capas.html
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Where Is the Tropopause?