atmosphere

Examples of atmosphere in the following topics:

• The Greenhouse Effect

  • The greenhouse effect is an elevation in surface temperatures due to atmospheric gases absorbing and re-radiating thermal energy.
  • While about 30 percent of the solar radiation directed at the Earth scatters at the outer atmosphere, the remainder is either absorbed by clouds and atmospheric gases or is transmitted to the Earth's surface.
  • The majority of gases in the atmosphere, such as nitrogen, oxygen, and argon, cannot absorb this infrared radiation.
  • Gases known as greenhouse gases, including water vapor, carbon dioxide, ozone, and methane, absorb and trap this heat as it tries to escape from the atmosphere.
  • Greenhouse gases then re-radiate this energy back to Earth, elevating atmospheric temperatures even when the surface is not being directly irradiated by the sun.

• Earth's Atmosphere

  • The Earth's atmosphere is a layer of mixed gases that is trapped near the surface due to gravitational forces.
  • The Earth's atmosphere is composed of a layer of gases that encase the planet and that are constrained by gravitational forces.
  • In the 1800s, scientists, including John Dalton, realized that the atmosphere was composed of a variety of gases.
  • In the recent past, we have damaged our ozone layer by putting chlorofluorocarbons (CFCs) into the atmosphere.
  • Recall the composition and relative amounts of the various gases that make up the Earth's atmosphere and how the atmosphere helps the planet survive

• Air Pollution

  • Air pollution results from increasing levels of harmful molecules and particulates in the atmosphere.
  • Air pollution is the presence of harmful molecules or particulates, both natural and man-made, in the atmosphere.
  • The greenhouse effect: an elevation in the Earth's surface temperature due to the absorption of electromagnetic radiation by atmospheric gases.
  • Acid rain: acidic precipitation that occurs when the pollutants sulfur dioxide and nitrogen oxide react with water in the atmosphere.
  • Air pollutants are considered primary when the harmful particles are directly emitted into the atmosphere; secondary pollutants are products of reactions that occur following emission.

• Glow of Space Shuttles

  • The glow observed as a space shuttle re-enters the atmosphere is due to excited NO2 releasing light to return to its ground state.
  • When space shuttles return from space and being to re-enter the Earth's atmosphere, a glow, especially around the tail end of the shuttle, can often be observed.
  • This phenomenon has to do with the composition of the atmosphere at these altitudes and the lack of shielding from the sun.
  • The origin of the NO is unclear, although it may be collected from the atmosphere or be a byproduct of the fuel consumption from the shuttle thrusters.
  • Recall that excited-state nitrogen dioxide is responsible for the glow observed as space shuttles re-enter Earth's atmosphere.

• Aurora Borealis and the Aurora Australis

  • Aurora borealis and australis are glowing sky phenomena that occur when charged particles from the sun excite atmospheric molecules.
  • The charged particles originate in the magnetosphere and solar wind and then are directed by the Earth's magnetic field into the atmosphere.
  • Instead, this energetic flow of particles is attracted to the Earth's magnetic field, where it collides with oxygen and nitrogen in the top regions of the atmosphere.
  • The movement of these charged particles also causes electricity, which serves to further excite the molecules in the Earth's atmosphere.
  • Collisions become more frequent farther down in the atmosphere, and red emissions do not have time to happen; eventually, even green light emissions are prevented.

• Properties of Nitrogen

  • Nitrogen in its elemental form is a non-metallic gas that makes up 78 percent of Earth's atmosphere.
  • However, as on Earth, nitrogen and its compounds occur commonly as gases in the atmospheres of planets and moons.
  • The nitrogen cycle describes the movement of the element from the air into the biosphere and organic compounds and back into the atmosphere.
  • Nitrogen absorption leads to significant absorption of ultraviolet radiation in the Earth's upper atmosphere and the atmospheres of other planetary bodies.
  • As a modified atmosphere, pure or mixed with carbon dioxide, to preserve the freshness of packaged or bulk foods

• Isotopes

  • Carbon is normally present in the atmosphere in the form of gaseous compounds like carbon dioxide and methane.
  • This is a continuous process so more 14C is always being created in the atmosphere.
  • Once produced, the 14C often combines with the oxygen in the atmosphere to form carbon dioxide.
  • Carbon dioxide produced in this way diffuses in the atmosphere, is dissolved in the ocean, and is incorporated by plants via photosynthesis.
  • In living organisms, the relative amount of 14C in their body is approximately equal to the concentration of 14C in the atmosphere.

• Density Calculations

  • However, in its most common form, the Ideal Gas Equation is not useful for examining the behavior of gases of undetermined volume, such as the gases in the clouds that surround the stars in our solar system or the atmospheric gases that support life on our planet.
  • Atmospheric science offers one plausible real-life application of the density form of the ideal gas equation.
  • Earth's atmosphere is composed of gases that support life—as the image shows, oxygen involved in the water cycle, sulfur emissions from oceans, methane from agriculture, and more.

• Alkyl Halide Occurrence

  • The ocean is the largest known source for atmospheric methyl bromide and methyl iodide.
  • Furthermore, the ocean is also estimated to supply 10-20% of atmospheric methyl chloride, with other significant contributions coming from biomass burning, salt marshes and wood-rotting fungi.

• Ozone

  • It is an allotrope of oxygen that is much less stable than the diatomic allotrope (O2), breaking down with a half life of about half an hour in the lower atmosphere to O2.
  • Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges.
  • It is present in low concentrations throughout the Earth's atmosphere.
  • In total, ozone makes up only 0.6 parts per million of the atmosphere.
  • It is also unstable at high concentrations, decaying to ordinary diatomic oxygen (with a half-life of about half an hour in atmospheric conditions):