2.1 Layers of the atmosphere and their characteristics
3 min read•july 22, 2024
Earth's atmosphere is a complex system of layers, each with unique properties. From the where we live to the at the edge of space, these layers play crucial roles in protecting life and regulating our climate.
Understanding the atmosphere's structure helps us grasp , ozone depletion, and climate change. The in the shields us from harmful UV rays, while the troposphere is where most weather happens.
Atmospheric Layers and Characteristics
Layers of Earth's atmosphere
Top images from around the web for Layers of Earth's atmosphere
Layers of the Atmosphere | Physical Geography View original
Is this image relevant?
sciencepage622 - The Five layers Of The Atmosphere-Andy View original
Is this image relevant?
File:Atmospheric Layers.svg - Wikimedia Commons View original
Is this image relevant?
Layers of the Atmosphere | Physical Geography View original
Is this image relevant?
sciencepage622 - The Five layers Of The Atmosphere-Andy View original
Is this image relevant?
1 of 3
Top images from around the web for Layers of Earth's atmosphere
Layers of the Atmosphere | Physical Geography View original
Is this image relevant?
sciencepage622 - The Five layers Of The Atmosphere-Andy View original
Is this image relevant?
File:Atmospheric Layers.svg - Wikimedia Commons View original
Is this image relevant?
Layers of the Atmosphere | Physical Geography View original
Is this image relevant?
sciencepage622 - The Five layers Of The Atmosphere-Andy View original
Is this image relevant?
1 of 3
- Troposphere
- Lowest layer extends from Earth's surface to an average altitude of 12 km (7.5 miles)
- Contains 75-80% of the atmosphere's mass and nearly all water vapor and aerosols
- Stratosphere
- Layer above the troposphere extends from the to an altitude of about 50 km (31 miles)
- Contains the ozone layer which absorbs harmful UV from the sun
-
- Layer above the stratosphere extends from the to an altitude of about 85 km (53 miles)
- Coldest layer where temperatures can drop to -90°C (-130°F) at the mesopause
-
- Layer above the mesosphere extends from the mesopause to an altitude between 500-1,000 km (311-621 miles)
- (northern and southern lights) occur in this layer due to charged particles from the sun
- Exosphere
- Outermost layer extends from the thermopause to an altitude of about 10,000 km (6,200 miles)
- Transitional zone between Earth's atmosphere and outer space
Characteristics of atmospheric layers
- Troposphere
- Temperature decreases with altitude at an average of 6.5°C/km (3.6°F/1,000 ft)
- Pressure and density decrease rapidly with altitude
- Contains almost all atmospheric water vapor and is where most weather phenomena occur (clouds, precipitation)
- Stratosphere
- Temperature increases with altitude due to ozone absorbing UV radiation
- Pressure continues decreasing with altitude but more slowly than in the troposphere
- Very dry and stable layer with little vertical mixing
- Mesosphere
- Temperature decreases with altitude reaching the coldest point at the mesopause
- Pressure continues decreasing and is about 1/1000th of sea level pressure at the top
- Noctilucent clouds can form at the top of this layer during summer at high latitudes
- Thermosphere
- Temperature increases significantly with altitude and can reach up to 2,000°C (3,632°F)
- is very low but individual gas molecules can reach high speeds
- Highly variable temperatures due to solar activity and the diurnal cycle
- Exosphere
- Extremely thin layer with negligible
- Hydrogen and helium are the main components and can escape into space
- Satellites (ISS) and the aurora (northern lights) occur in this layer
Function of atmospheric boundaries
- Tropopause
- Boundary between the troposphere and stratosphere around 12 km (7.5 miles) altitude
- Marked by abrupt change in lapse rate from positive (troposphere) to negative (stratosphere)
- Acts as a "lid" that limits the vertical rise of air from the troposphere, controlling weather
- Stratopause
- Boundary between the stratosphere and mesosphere around 50 km (31 miles) altitude
- Marked by a reversal in lapse rate from negative (stratosphere) to positive (mesosphere)
- Separates the stable stratosphere from the turbulent mesosphere
Ozone layer in stratosphere
- Ozone layer
- Region of naturally high ozone () concentrations within the stratosphere
- Located roughly 20-30 km (12-19 miles) above Earth's surface
-
- Ozone absorbs harmful solar ultraviolet (UV) radiation, especially UV-B and UV-C wavelengths
- Protects life on Earth's surface from DNA damage and higher skin cancer risk
- Stratospheric temperature inversion
- Ozone absorbing UV radiation causes the unusual temperature increase with altitude
- Creates a stable layer with limited vertical mixing between the troposphere and stratosphere
-
- Chlorofluorocarbons (CFCs) and other manufactured chemicals can deplete ozone
- Ozone holes (severe depletion) can develop over polar regions during late winter/early spring
Key Terms to Review (22)
Advection: Advection is the horizontal movement of air or water, often carrying heat, moisture, and other properties from one location to another. This process plays a significant role in weather patterns, influencing temperature and humidity levels as air masses move across different regions. Understanding advection helps explain how energy is distributed within the atmosphere, affecting climate and local weather phenomena.
Air Density: Air density is the mass of air per unit volume, typically expressed in kilograms per cubic meter (kg/m³). It plays a critical role in various atmospheric processes, influencing weather patterns, air pressure, and the behavior of gases within the different layers of the atmosphere. Variations in air density can affect how temperature changes impact climate and can also determine the altitude at which aircraft operate efficiently.
Anthropogenic ozone depletion: Anthropogenic ozone depletion refers to the reduction of the ozone layer in the Earth's stratosphere caused primarily by human activities, particularly through the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODS). This thinning of the ozone layer leads to increased ultraviolet (UV) radiation reaching the Earth's surface, which can have harmful effects on human health, ecosystems, and climate systems.
Atmospheric pressure: Atmospheric pressure is the force exerted by the weight of the air above a given point on Earth's surface. It decreases with altitude, meaning that as you go higher in the atmosphere, there is less air above you, leading to lower pressure. This concept is crucial for understanding various phenomena in meteorology and how different layers of the atmosphere function.
Auroras: Auroras are natural light displays predominantly seen in high-latitude regions around the Arctic and Antarctic, caused by the interaction of charged particles from the sun with the Earth's magnetic field and atmosphere. These mesmerizing phenomena occur when solar wind particles collide with gases in the atmosphere, leading to brilliant lights that dance across the sky, typically manifesting as green, red, or purple hues. The beautiful displays of auroras are more than just a visual spectacle; they are also a testament to the complex interactions between solar activity and our planet's atmospheric layers.
Convection: Convection is the process of heat transfer through the movement of fluids, including liquids and gases, caused by differences in temperature and density. This movement occurs as warmer, less dense fluid rises while cooler, denser fluid sinks, creating a cycle that transfers heat throughout the material. Convection plays a crucial role in various natural processes, including the distribution of heat within the Earth’s atmosphere and oceans, influencing weather patterns and climate.
Exosphere: The exosphere is the outermost layer of Earth's atmosphere, extending from about 600 kilometers (373 miles) above sea level to approximately 10,000 kilometers (6,200 miles). This layer is characterized by extremely low densities of particles and temperatures that can reach up to 2,500°C (4,532°F). The exosphere marks the transition between Earth's atmosphere and outer space, where atoms and molecules can escape into space due to minimal gravitational pull.
Humidity: Humidity refers to the amount of water vapor present in the air, which plays a crucial role in weather and climate. It affects how humans perceive temperature and can influence precipitation patterns, cloud formation, and overall atmospheric conditions. Understanding humidity is essential for grasping concepts related to the movement of water through the atmosphere and the various processes that occur within it.
Hydrological cycle: The hydrological cycle, also known as the water cycle, is the continuous movement of water within the Earth and atmosphere, involving processes like evaporation, condensation, precipitation, and runoff. This cycle is crucial for maintaining ecosystems, influencing climate, and shaping weather patterns. It connects various atmospheric layers, as well as impacts precipitation patterns and extreme weather events by determining how water is distributed and transformed in the environment.
Lapse rate: The lapse rate is the rate at which temperature decreases with an increase in altitude in the atmosphere. This concept is crucial for understanding how different layers of the atmosphere behave, as the lapse rate varies between layers and influences weather patterns, air pressure, and climate change.
Mesosphere: The mesosphere is the third layer of Earth's atmosphere, situated above the stratosphere and below the thermosphere, extending from about 50 to 85 kilometers (31 to 53 miles) above sea level. This layer is characterized by a decrease in temperature with increasing altitude, where temperatures can drop as low as -90°C (-130°F). The mesosphere plays a critical role in atmospheric dynamics and is the region where most meteoroids burn up upon entering Earth's atmosphere.
Ozone layer: The ozone layer is a region of Earth's stratosphere that contains a high concentration of ozone (O₃) molecules, which absorbs the majority of the sun's harmful ultraviolet (UV) radiation. This layer is crucial for protecting living organisms from excessive UV exposure, which can lead to skin cancer, cataracts, and other health issues, as well as environmental impacts like harm to ecosystems.
Radiation: Radiation is the process by which energy is emitted as particles or waves. This energy transfer plays a crucial role in the Earth's climate system, as it is the primary way that solar energy reaches the planet and drives atmospheric and oceanic processes. Radiation can take various forms, including visible light, infrared, and ultraviolet, each influencing the environment differently, such as heating the Earth's surface or affecting atmospheric layers.
Radiosonde: A radiosonde is a small, lightweight instrument carried aloft by a weather balloon that measures atmospheric parameters such as temperature, humidity, and pressure as it ascends through the atmosphere. This data is crucial for understanding the layers of the atmosphere and their characteristics, as it provides valuable insights into weather patterns, climate conditions, and atmospheric phenomena.
Satellite remote sensing: Satellite remote sensing is the technology that uses satellite-based sensors to collect data about the Earth's surface and atmosphere from a distance. This technique enables scientists to monitor and analyze various environmental conditions, such as land cover, temperature changes, and atmospheric composition, which play crucial roles in understanding climate dynamics, weather patterns, and ecological health.
Stratopause: The stratopause is the boundary layer that separates the stratosphere from the mesosphere in Earth’s atmosphere, occurring at an altitude of about 50 kilometers (31 miles) above sea level. This region marks a transition where temperature stops increasing with altitude, a characteristic behavior of the stratosphere, and begins to decrease, which is typical for the mesosphere. Understanding the stratopause is essential for comprehending atmospheric dynamics and temperature profiles across different layers of the atmosphere.
Stratosphere: The stratosphere is the second layer of Earth's atmosphere, situated above the troposphere and extending from about 10 to 50 kilometers above the Earth's surface. It is characterized by a temperature increase with altitude and contains the ozone layer, which plays a crucial role in absorbing harmful ultraviolet radiation from the sun.
Thermosphere: The thermosphere is the layer of Earth's atmosphere located above the mesosphere and below the exosphere, characterized by a rapid increase in temperature with altitude. This layer contains a small amount of gas, but the gases present are highly energetic and can reach temperatures of up to 2,500°C or more, primarily due to the absorption of solar radiation. The thermosphere is also where the auroras occur and is crucial for radio communication due to its ionization effects.
Tropopause: The tropopause is the boundary layer between the troposphere and the stratosphere in the Earth's atmosphere. It plays a critical role in atmospheric dynamics, acting as a cap that limits the vertical mixing of air and weather phenomena, while also marking a significant change in temperature gradient and atmospheric pressure.
Troposphere: The troposphere is the lowest layer of Earth's atmosphere, extending from the surface up to about 8 to 15 kilometers (5 to 9 miles) high, depending on latitude and weather conditions. This layer is crucial because it contains most of the atmosphere's mass, including water vapor and clouds, and is where nearly all weather phenomena occur, making it essential in understanding climate patterns and changes.
Uv protection: UV protection refers to the methods and materials used to shield living organisms, particularly humans, from the harmful effects of ultraviolet (UV) radiation emitted by the sun. This radiation can cause skin damage, increase the risk of skin cancer, and lead to other health issues. Understanding UV protection is crucial, as it relates closely to the layers of the atmosphere that filter out some of this radiation before it reaches the Earth's surface.
Weather patterns: Weather patterns refer to the recurring meteorological conditions in a specific area over time, encompassing elements such as temperature, humidity, precipitation, and wind. These patterns are influenced by various factors, including geographic location, time of year, and atmospheric layers, which affect how weather systems develop and change.