Air pressure changes with altitude because of issues related to gravity. Molecules have more weight the closer they are to the Earth and more of them move to lower elevations as a result; this causes increased pressure because there are more molecules in number and proximity. Conversely, air at higher elevations has less weight, but also forces pressure on those layers below it, resulting in the molecules closer to the Earth supporting more weight, increasing the pressure.Know More
In weather, air pressure plays an important part of forecasting. Both high and low pressure affect the conditions when one walks outside.
As air cools and rises in low pressure area, it form condensation and clouds that will culminate in a rain storm; in a high pressure system, the weather is relatively stable.
As air pressure is a constant in weather, news reports include a "high" and "low" pressure indicator. The science has developed an indicator for measuring the density of the air in any given place. Pressure in high is recorded in hectoPascals.
In a high pressure system in the Northern Hemisphere, winds blow clockwise and the air moves toward the Earth. In a low pressure system the air moves in a clockwise direction and rises, causing clouds as it cools.Learn more about Atmosphere
Air is important for the planet because it contains the gases necessary to support plants, animals and other organisms. Additionally, the presence of an atmosphere keeps the Earth at a habitable temperature.Full Answer >
A barometer is the scientific instrument used by meteorologists to measure atmospheric pressure. There are three main types of barometers: mercury, aneroid and digital barometers.Full Answer >
Air pressure, the force exerted on a mass by the weight of air particles, is measured in either inches of mercury or in millibars, represented by inHg and mb, respectively. One standard atmosphere, represented by the symbol atm, is equal to 29.92 inHg, or 1013.25 mb.Full Answer >
The air humans breathe is made up of about 78 percent nitrogen, 21 percent oxygen, and 1 percent carbon dioxide and argon. Trace gases include krypton, methane, neon, helium and hydrogen. Air generally contains trace amounts of water vapor, as well, with greater concentrations occurring near sea level.Full Answer >