Question:

What is value of atmospheric pressure at sea level?

Answer:

The average sea-level air pressure reading is 1013.25 mb. The usual worldwide range in sea level pressure is about 970 to 1040 mb

More Info:

Atmospheric pressure is the force per unit area exerted on a surface by the weight of air above that surface in the atmosphere of Earth (or that of another planet). In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. On a given plane, low-pressure areas have less atmospheric mass above their location, whereas high-pressure areas have more atmospheric mass above their location. Likewise, as elevation increases, there is less overlying atmospheric mass, so that atmospheric pressure decreases with increasing elevation. On average, a column of air one square centimeter in cross-section, measured from sea level to the top of the atmosphere, has a mass of about 1.03 kg and weight of about 10.1 N (2.28 flb) (A column one square inch in cross-section would have a weight of about 14.7 lbs, or about 65.4 N).

The standard atmosphere (symbol: atm) is a unit of pressure equal to 101325 Pa or 1013.25 millibars or hectopascals. It is equivalent to 760 mmHg (torr), 29.92 inHg, 14.696 psi.

Atmospheric pressure is the force per unit area exerted on a surface by the weight of air above that surface in the atmosphere of Earth (or that of another planet). In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. On a given plane, low-pressure areas have less atmospheric mass above their location, whereas high-pressure areas have more atmospheric mass above their location. Likewise, as elevation increases, there is less overlying atmospheric mass, so that atmospheric pressure decreases with increasing elevation. On average, a column of air one square centimeter in cross-section, measured from sea level to the top of the atmosphere, has a mass of about 1.03 kg and weight of about 10.1 N (2.28 flb) (A column one square inch in cross-section would have a weight of about 14.7 lbs, or about 65.4 N).

The standard atmosphere (symbol: atm) is a unit of pressure equal to 101325 Pa or 1013.25 millibars or hectopascals. It is equivalent to 760 mmHg (torr), 29.92 inHg, 14.696 psi.

Atmosphere Meteorology

Atmospheric physics
Atmospheric dynamics (category)

Weather (category) · (portal)

Physics

Atmospheric thermodynamics is the study of heat to work transformations (and the reverse) in the earth’s atmospheric system in relation to weather or climate. Following the fundamental laws of classical thermodynamics, atmospheric thermodynamics studies such phenomena as properties of moist air, formation of clouds, atmospheric convection, boundary layer meteorology, and vertical stabilities in the atmosphere. Atmospheric thermodynamic diagrams are used as tools in the forecasting of storm development. Atmospheric thermodynamics forms a basis for cloud microphysics and convection parameterizations in numerical weather models, and is used in many climate considerations, including convective-equilibrium climate models.

Atmospheric thermodynamics focuses on water and its transformations. Areas of study include the law of energy conservation, the ideal gas law, specific heat capacities, adiabatic processes (in which entropy is conserved), and moist adiabatic processes. Most of tropospheric gases are treated as ideal gases and water vapor is considered as one of the most important trace components of air.

Thermodynamics

Underwater diving is the practice of going underwater, either with breathing apparatus (scuba diving and surface supplied diving) or by breath-holding (freediving).

Underwater diving methods include Free-diving, Scuba diving, Surface-supplied diving, Saturation diving, and diving in Atmospheric diving suits.

Pressure (symbol: P or p) is the ratio of force to the area over which that force is distributed.

Pressure is force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure (also spelled gage pressure) is the pressure relative to the local atmospheric or ambient pressure. Pressure is measured in any unit of force divided by any unit of area. The SI unit of pressure is the newton per square metre, which is called the pascal (Pa) after the seventeenth-century philosopher and scientist Blaise Pascal. A pressure of 1 Pa is small; it approximately equals the pressure exerted by a dollar bill resting flat on a table. Everyday pressures are often stated in kilopascals (1 kPa = 1000 Pa).

Mean sea level (MSL) is a datum representing the average height of the ocean's surface (such as the halfway point between the mean high tide and the mean low tide); used as a standard in reckoning land elevation. MSL also plays an important role in marine navigation as a chart datum and aviation, where standard sea level pressure is used as the measurement datum of altitude at flight levels. Detection of long-term variations of mean sea level requires careful measurement but can provide information on climate change. Over geologic time, sea levels have changed dramatically.

Precise determination of a "mean sea level" is a difficult problem because of the many factors that affect sea level. Sea level varies quite a lot on several scales of time and distance. This is because the sea is in constant motion, affected by the tides, wind, atmospheric pressure, local gravitational differences, temperature, salinity and so forth. The best one can do is to pick a spot and calculate the mean sea level at that point and use it as a datum. For example, a period of 19 years of hourly level observations may be averaged and used to determine the mean sea level at some measurement point.

Pressure Bar Environment
News:


Related Websites:


Terms of service | About
5