Atmosphere Summary

     The atmosphere is a peculiar place. It's composed of several layers-- the troposphere, stratosphere, mesophere, thermospere, and exosphere (in increasing order)-- and is composed mainly of nitrogen gas.  These many layers are defined by trends in average air temperature, which changes with pressure and radiation. Wind is also caused by air pressure, where warmer, less dense air, follows colder, denser air. Areas of high pressure like to expand into areas of low pressure. Air pressure decreases rapidly with height because gravity pulls gases closer to the Earth's surface.
     The many levels of the atmosphere all sport their own types of clouds, stratus and cumulus in the lower levels and cirrus in the highest. Clouds are defined by their shape and altitude and are composed of condensed water vapor in the form of droplets. Humidity measures the water vapor in the air and relative humidity measures the amount of water vapor in the air versus the capacity if the air to hold water vapor.
     Aerosols and pollutants also effect the atmosphere, particularly in regards to the Green House Effect, the gradual warming of the Earth's atmosphere (which is mostly caused by water vapor and CO2). Although nitrogen and oxygen levels are consistent, carbon dioxide, methane, and nitrogen oxide levels are rising rapidly. Carbon dioxide levels have risen 18% since 1958 alone. Ground smog, another pollutant, is mostly caused by reactants of nitrogen, VOCs, and ozone.
     Solar radiation is another important part of the weather and atmosphere. Albedo describes the amount of solar radiation reflected by objects and absorption describes the amount of solar radiation being absorbed by surfaces. The average albedo of Earth's surfaces is 31%. Some surfaces, usually modified by man, absorb more solar radiation than usual, emitting it in large frequencies in the evening, this is known as the Urban Heat Island Effect.