fv4 - atmosphere

AP Environmental Science: Earth's Atmosphere Study Guide

Page 1: Major Gases

  • Composition of the Atmosphere

    • Mainly composed of oxygen (O2) and nitrogen (N2).

    • Nitrogen is released through denitrification and the nitrogen cycle.

    • Oxygen is released through photosynthesis by plants.

  • Water Vapor

    • Water vapor (H2O) is a significant gas, more concentrated around the equator than the poles.

  • Greenhouse Gases

    • Includes methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O).

    • These gases trap heat in the atmosphere, contributing to global warming.

    • Released during the burning of fossil fuels, which has increased greenhouse gas emissions.

  • Ozone Layer

    • Ozone (O3) absorbs harmful UV radiation from the sun.

    • Protects the troposphere from excessive UV rays.

    • Damaged by chlorofluorocarbons (CFCs).

Page 2: Layers of the Atmosphere

  • Troposphere

    • Closest layer to Earth, extends up to about 10 km.

    • Temperature decreases with altitude; all weather occurs here.

  • Stratosphere

    • Ranges from 10 km to 50 km.

    • Contains the ozone layer; temperature increases with altitude due to UV absorption.

  • Mesosphere

    • Extends from 50 km to 80 km.

    • Temperature decreases with altitude; can reach below -80 °C.

  • Thermosphere

    • Ranges from 80 km to 100 km; also known as the ionosphere.

    • Temperature increases with altitude; traps solar protons and electrons.

  • Exosphere

    • Highest layer, from about 700 km to 10,000 km.

    • Merges with solar wind; low density of molecules.

    • Satellites orbit this layer; auroras can be seen at its lowest point.

Page 3: Key Terms and Climate Implications

  • Water Vapor Concentration

    • Higher at the equator, lower at the poles; affects climate patterns.

  • Key Terms

    • Aurora Borealis: Northern Lights, caused by solar particles interacting with the atmosphere.

    • Aurora Australis: Southern Lights, similar to Aurora Borealis but in the southern hemisphere.

    • Chlorofluorocarbons (CFCs): Harmful synthetic compounds that damage the ozone layer.

    • Denitrification: Process converting nitrates into nitrogen gas, releasing it into the atmosphere.

    • Fossil Fuels: Energy-rich substances that release greenhouse gases when burned.

Page 4: Additional Concepts

  • Greenhouse Gases

    • Contribute to the greenhouse effect and global warming.

  • Nitrogen Cycle

    • Involves processes like nitrogen fixation, nitrification, and denitrification.

  • Ozone Layer

    • Crucial for filtering UV radiation before it reaches Earth's surface.

  • Photosynthesis

    • Process by which plants convert sunlight, CO2, and water into glucose and oxygen,