Atmospheric pressure, also referred to as
air pressure or barometric pressure, refers to the
force exerted by the weight of the
Earth's atmospheric gases on a specific
area. This
parameter significantly influences
meteorological phenomena, drives
air movement, and governs
gas behaviors.
Measurement units for atmospheric pressure include pascals (Pa), millibars (mb), and inches of
mercury (inHg).
How Atmospheric Pressure is Measured
Barometer: Barometers are instrumental in the measurement of atmospheric pressure. The two widely used types of barometers are mercury and
aneroid. Mercury barometers employ a column of
liquid mercury to offset the force of the
atmosphere, whereas aneroid barometers use a sealed, flexible metal cell that alters its
shape in response to
air pressure
variations.
Altimeter: Altimeters are commonly utilized in
aviation and
mountain climbing to approximate
altitude using atmospheric pressure. Atmospheric pressure decreases with the increase in altitude, thereby allowing the altimeter to furnish an estimated altitude.
Factors Influencing Atmospheric Pressure
Altitude: Altitude is a significant contributor to atmospheric pressure. As one ascends in altitude, the
density of air molecules diminishes, leading to a decrease in atmospheric pressure. Therefore, regions at high altitudes typically register lower air pressure than
sea-
level regions.
Temperature: Atmospheric pressure is also sensitive to temperature. Warmer, less
dense air rises, triggering a reduction in air pressure. Conversely, colder, denser air descends, causing a rise in air pressure.
Weather Systems:
Weather patterns are largely driven by high and
low-pressure systems.
High-pressure systems, characterized by
descending air, clear skies, and calm weather, contrast with low-pressure systems associated with rising air,
cloud production, and
rainfall.
Atmospheric Pressure and Human Health
Pressure Changes: Rapid changes in atmospheric pressure, occurring during activities like
air travel or mountain climbing, can cause temporary discomfort and minor health issues. These might include pain in the ear or difficulties in balancing pressure in the middle ear, and occasionally
mild altitude sickness.
Chronic Low Pressure: Long-term exposure to low atmospheric pressure, often experienced when living at high altitudes, can cause physiological changes in the human
body. These changes might involve an increased production of red blood cells to enhance oxygen-carrying capacity and adjustments in
respiratory operations.
Atmospheric pressure information is an essential element in weather
forecasting.
Meteorologists study pressure patterns to identify and track high and low-pressure systems, assisting them in predicting weather conditions and possible storms. Observing alterations in atmospheric pressure can provide early signals for the onset of
severe weather phenomena, including
tornadoes and hurricanes.
Updated: Jun 1, 2023
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