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NRLMSISE-00 is a newer model of the Earth's atmosphere from ground to space, developed by the US Naval Research Laboratory taking actual satellite drag data into account. A primary use of this model is to aid predictions of satellite orbital decay due to atmospheric drag.
Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth.The standard atmosphere (symbol: atm) is a unit of pressure defined as 101,325 Pa (1,013.25 hPa), which is equivalent to 1,013.25 millibars, [1] 760 mm Hg, 29.9212 inches Hg, or 14.696 psi. [2]
The basic assumptions made for the 1962 version were: [3] air is a clean, dry, perfect gas mixture (c p /c v = 1.40) molecular weight to 90 km of 28.9644 (C-12 scale); principal sea-level constituents are assumed to be (in mole percent):
The unit is named after Blaise Pascal, noted for his contributions to hydrodynamics and hydrostatics, and experiments with a barometer.The name pascal was adopted for the SI unit newton per square metre (N/m 2) by the 14th General Conference on Weights and Measures in 1971.
Atmospheric physics has close links to meteorology and climatology and also covers the design and construction of instruments for studying the atmosphere and the interpretation of the data they provide, including remote sensing instruments. In the United Kingdom, atmospheric studies are underpinned by the Meteorological Office.
Up until the 1940s, astronomers used optical telescopes to observe distant astronomical objects whose radiation reached the earth through the optical window. After that time, the development of radio telescopes gave rise to the more successful field of radio astronomy that is based on the analysis of observations made through the radio window.
The dispersion models vary depending on the mathematics used to develop the model, but all require the input of data that may include: Meteorological conditions such as wind speed and direction, the amount of atmospheric turbulence (as characterized by what is called the "stability class" ), the ambient air temperature, the height to the bottom ...
SI base units Name Symbol Measure Post-2019 formal definition [1] Historical origin / justification Dimension symbol; second: s time "The second, symbol s, is the SI unit of time.