Acidic substances remain in the atmosphere for 2-14 days, depending mostly on prevailing winds, precipitation, and other weather patterns. During this period, they descend to the earth's surface in two forms: wet deposition consisting of acidic rain, snow, fog, and cloud vapor with a pH less than 5.6* and dry deposition consisting of acidic particles. The resulting mixture is called acid rain.
the presence of chemicals in the atmosphere in concentrations high enough to harm organisms, ecosystems, or human-made materials.
the force, or mass, per unit area of a column of air. This force is caused by the bombardment of a surface such as your skin by air molecules.
Carbon monoxide (CO) is a colorless, odorless, and highly toxic gas that forms during the incomplete combustion of carbon-containing materials.
the air we breathe at sea level is higher—more molecules per liter—than the air we would inhale on top of the world's highest mountain.
consisting mostly of sulfur dioxide, suspended droplets of sulfuric acid, and a variety of suspended solid particles.
nitrogen oxides and nitric acid
Nitric oxide (NO) is a colorless gas that forms when nitrogen and oxygen gas in air react at the high-combustion temperatures in automobile engines and coal-burning plants.
a colorless and highly reactive gas, is a major component of photochemical smog.
Much of the atmosphere's small amount of ozone (O3) is concentrated in this portion of the stratosphere, found roughly 17-30 kilometers (11-19 miles) above sea level.
consists of a variety of solid particles and liquid droplets small and light enough to remain suspended in the air for long periods, aka suspended particulate matter (SPM).
a mixture of primary and secondary pollutants formed under the influence of UV radiation from the sun.
harmful chemicals emitted directly into the air from natural processes and human activities.
While in the atmosphere, some primary pollutants react with one another and with the basic components of air to form new harmful chemicals.
The atmosphere's second layer, which extends from about 17 to about 48 kilometers (from 11 to 30 miles) above the earth's surface.
sulfur dioxide (SO2) and sulfuric acid
A colorless gas with an irritating odor. About one-third of this in the atmosphere comes from natural sources as part of the sulfur cycle.
Under certain atmospheric conditions, a layer of warm air can temporarily lie atop a layer of cooler air nearer the ground.
About 75-80% of the earth's air mass is found in this layer, the atmospheric layer closest to the earth's surface.
volatile organic compounds (VOCs)
Organic compounds that exist as gases in the atmosphere.