Atmospheric Science Basics

Definition and Scope

• Atmospheric science is the study of the Earth's atmosphere, including its composition, properties, and processes.
• It is an interdisciplinary field that combines principles from meteorology, climatology, and atmospheric chemistry.

Atmospheric Layers

• Troposphere: lowest layer, extends up to 12 km, where weather occurs
• Stratosphere: 12-50 km, stable layer with ozone layer
• Mesosphere: 50-80 km, where meteors burn up
• Thermosphere: 80-600 km, where aurorae occur
• Exosphere: outermost layer, where atmospheric gases escape into space

Atmospheric Composition

• Nitrogen (N2): 78%
• Oxygen (O2): 21%
• Argon (Ar): 1%
• Carbon dioxide (CO2): 0.04%
• Water vapor (H2O): variable, up to 4%
• Other gases: neon, helium, methane, krypton, xenon

Atmospheric Processes

• Evaporation: liquid water becomes water vapor
• Condensation: water vapor becomes liquid water
• Transpiration: plants release water vapor
• Precipitation: water falls to the ground
• Atmospheric circulation: wind patterns and global air movements

Climate and Weather

• Weather: short-term atmospheric conditions (temperature, humidity, cloudiness, etc.)
• Climate: long-term average atmospheric conditions (temperature, precipitation, etc.)
• Climate change: long-term changes in atmospheric conditions, including global warming

Tools and Techniques

• Weather stations: measure temperature, humidity, wind, and precipitation
• Radar: uses radio waves to detect precipitation
• Satellites: observe atmospheric conditions from space
• Computer models: simulate atmospheric processes and predict weather and climate patterns

Atmospheric Science

• Interdisciplinary field combining meteorology, climatology, and atmospheric chemistry to study the Earth's atmosphere, its composition, properties, and processes.

Atmospheric Layers

• Troposphere: lowest layer, 12 km high, where weather occurs.
• Stratosphere: 12-50 km high, stable layer with ozone layer.
• Mesosphere: 50-80 km high, where meteors burn up.
• Thermosphere: 80-600 km high, where aurorae occur.
• Exosphere: outermost layer, where atmospheric gases escape into space.

Atmospheric Composition

• Nitrogen (N2): 78% of the atmosphere.
• Oxygen (O2): 21% of the atmosphere.
• Argon (Ar): 1% of the atmosphere.
• Carbon dioxide (CO2): 0.04% of the atmosphere.
• Water vapor (H2O): variable, up to 4% of the atmosphere.
• Other gases: neon, helium, methane, krypton, xenon, present in trace amounts.

Atmospheric Processes

• Evaporation: liquid water becomes water vapor, increasing atmospheric humidity.
• Condensation: water vapor becomes liquid water, forming clouds, fog, or dew.
• Transpiration: plants release water vapor into the atmosphere.
• Precipitation: water falls to the ground, including rain, snow, sleet, or hail.
• Atmospheric circulation: wind patterns and global air movements that distribute heat and moisture around the globe.

Climate and Weather

• Weather: short-term atmospheric conditions, including temperature, humidity, cloudiness, wind, and precipitation.
• Climate: long-term average atmospheric conditions, including temperature, precipitation, and weather patterns.
• Climate change: long-term changes in atmospheric conditions, including global warming and shifts in precipitation patterns.

Tools and Techniques

• Weather stations: measure temperature, humidity, wind, and precipitation on the ground.
• Radar: uses radio waves to detect precipitation, tracking storms and monitoring weather patterns.
• Satellites: observe atmospheric conditions from space, monitoring weather patterns, climate, and atmospheric phenomena.
• Computer models: simulate atmospheric processes, predicting weather and climate patterns, and forecasting future changes.

Convection Currents

• Convection currents occur when a low-pressure region is created by heating, resulting in the movement of material.
• Example: Breezes over land masses next to large bodies of water.

Heat Capacity and Temperature Differences

• Water has a larger heat capacity than land, taking longer to change its temperature.
• During the day, air above the water is cooler than over the land, creating a low-pressure area over the land.
• At night, water cools off more slowly than the land, creating a low-pressure area over the water.

Sea Breezes

• Temperature differences between land and sea lead to the development of local winds called sea breezes.
• When the Sun heats the land, the air above it expands and rises, being replaced by cooler air from above the sea surface.

Atmospheric Science

• The atmospheric sciences comprise related and overlapping disciplines, including meteorology and climatology.
• The blanket of air around the Earth is called the atmosphere.

Composition of the Atmosphere

• The original atmosphere was likely different from the current one, possibly similar to the composition of the solar nebula.
• The current atmosphere is oxidizing, whereas the original atmosphere was reducing.
• The atmosphere is deficient in noble gases, such as helium, neon, xenon, and krypton.

Land and Sea Breezes

• Sea breezes are caused by heating near the ground, making the stratification weaker and encouraging vertical motion.
• Land breezes are produced by cooling near the ground, producing strong stratification and inhibiting vertical motion.
• Nighttime cooling produces a shallower change in temperature, resulting in a weaker flow.

Radiation

• Radiation refers to the transfer of heat through light, such as from the Sun to the Earth.
• This energy can be converted back into heat when it reaches the Earth's surface.