Exploring the Earth's atmosphere reveals a complex layer of gases, including nitrogen and oxygen, that supports life and influences weather and climate. The sun drives the hydrologic cycle, affecting diverse climates and ecosystems. Human activities, such as pollution and deforestation, have significantly impacted Earth's environment, altering climate patterns and affecting biodiversity. This text delves into the atmospheric layers, the role of the sun in weather systems, the importance of the hydrologic cycle, and the profound influence of human actions on our planet.
Show More
The atmospheric pressure at sea level is 101.325 kPa and decreases with altitude, while the density follows a scale height of 8.5 km
Major Gases
The dry atmosphere is mostly made up of nitrogen (78.084%) and oxygen (20.946%), with smaller amounts of argon (0.934%) and trace gases like carbon dioxide, neon, and helium
Water Vapor
Water vapor, which varies in concentration but averages around 1% by volume, is also present in the atmosphere and plays a crucial role in weather and climate
The composition of the atmosphere has changed over billions of years, with the rise of oxygenic photosynthesis around 2.7 billion years ago leading to the predominance of nitrogen and oxygen and the formation of the protective ozone layer
The Earth's atmosphere, particularly the troposphere, is integral to the dynamics of weather and climate, with solar heating causing air to circulate and redistribute heat and moisture around the globe
Solar Constant
The Earth receives an average of 1361 W/m² of solar energy, known as the solar constant, which influences regional temperatures
Climate Zones
The Earth's climate zones range from the consistently warm tropics to the frigid polar regions, with local climates further affected by factors such as proximity to bodies of water, atmospheric circulation patterns, and geographic features
Factors such as prevailing winds, mountain ranges, and ocean temperatures shape precipitation patterns and contribute to the formation of various weather patterns and climatic zones
The hydrologic cycle, powered by the sun, circulates water through evaporation, atmospheric transport, condensation, and precipitation, and is essential for sustaining life on land
Precipitation patterns are highly variable across the globe, influenced by factors such as prevailing winds, mountain ranges, and ocean temperatures
The Köppen climate classification system organizes Earth's climates into five primary groups based on temperature and precipitation patterns, with several subcategories reflecting more specific climate characteristics
The Earth's atmosphere is composed of several distinct layers, including the stratosphere, mesosphere, and thermosphere, each with unique temperature gradients and atmospheric phenomena
Stratosphere and Ozone Layer
The stratosphere is home to the ozone layer, which is vital for absorbing harmful ultraviolet radiation from the sun
Kármán Line
The Kármán line, situated roughly 100 km above the Earth's surface, is often used to represent the demarcation between the atmosphere and outer space
The upper atmosphere is subject to atmospheric escape, where lighter gases can be lost to space, leading to the historical transition of Earth's atmosphere from a reducing to an oxidizing state, which has had significant implications for the development and evolution of life on our planet
00
The layer of gases surrounding Earth, known as the ______, protects our planet and starts at the ground level, extending to outer space.
atmosphere
01
At the Earth's surface, specifically at sea level, the pressure of the atmosphere is approximately ______ kPa.
101.325
02
The advent of ______ photosynthesis around ______ billion years ago was a pivotal event that transformed the Earth's atmosphere, leading to the current dominance of nitrogen and oxygen.
oxygenic
2.7
