The Earth's atmosphere is 99% of atmospheric gases, with water vapor being the largest greenhouse gas. Other gases in the atmosphere (mainly in the troposphere) are nitrogen, oxygen, carbon dioxide, and other gasses. These gases are invisible, unlike smog that contains nitrogen and VOC's in the ozone. This is found in larger cities. Speaking of smog, the greenhouse effect is very important to teh atmosphere, even more so the ozone. Infrared radiation is emitted to Earth's surface due to the warming of the atmopshere. The main gases responsible for this are water vapor and carbon dioxide. Aerosols are also wtih the greenhouse effect (manmade, soil, salt, ash). Pressure is important with the atmosphere, pulling gases towards earth. The higher the pressure, air is thinner, making it harder to breathe.
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Solar radation cosists of albedo (radation reflected back into space) and absorption (radation not reflected into space). Urban heat island effect is usually found in metro areas. Clouds are definded by shape, form, and base altitude. Concerning wind and air pressure, warm air expans and leaves low pressure and cold air sinks and leaves high air pressure. Uneven heating makes some places warmer, and warm air follows cold air. Humidity is the amount of water vapor stuck inbetween molecules in the air and depends on air temperature.