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These figures should be compared with the temperature and density of Earth's atmosphere plotted at NRLMSISE-00, which shows the air density dropping from 1200 g/m 3 at sea level to 0.125 g/m 3 at 70 km, a factor of 9600, indicating an average scale height of 70 / ln(9600) = 7.64 km, consistent with the indicated average air temperature over ...
The troposphere is the lowest layer of Earth's atmosphere. It extends from Earth's surface to an average height of about 12 km (7.5 mi; 39,000 ft), although this altitude varies from about 9 km (5.6 mi; 30,000 ft) at the geographic poles to 17 km (11 mi; 56,000 ft) at the Equator, [17] with some variation due
The density of air or atmospheric density, denoted ρ, [1] is the mass per unit volume of Earth's atmosphere. Air density, like air pressure, decreases with increasing altitude. It also changes with variations in atmospheric pressure, temperature and humidity.
The NASA Earth Global Reference Atmospheric Model (Earth-GRAM) was developed by the Marshall Space Flight Center to provide a design reference atmosphere that, unlike the standard atmospheres, allows for geographical variability, a wide range of altitudes (surface to orbital altitudes), and different months and times of day. It can also ...
The COSPAR International Reference Atmosphere (CIRA) 2012 and the ISO 14222 Earth Atmosphere Density standard both recommend NRLMSISE-00 for composition uses. JB2008 is a newer model of the Earth's atmosphere from 120 km to 2000 km, developed by the US Air Force Space Command and Space Environment Technologies taking into account realistic ...
The Jacchia Reference Atmosphere is a reference atmospheric model that defines values for atmospheric temperature, density, pressure and other properties at altitudes from 90 to 2500 km. Unlike the more common US Standard Atmosphere and related models, the Jacchia model includes latitudinal, seasonal, geomagnetic, and solar effects, but must be ...
Earth's atmosphere has no definite boundary, gradually becoming thinner and fading into outer space. [219] Three-quarters of the atmosphere's mass is contained within the first 11 km (6.8 mi) of the surface; this lowest layer is called the troposphere. [220] Energy from the Sun heats this layer, and the surface below, causing expansion of the air.
The hypsometric equation, also known as the thickness equation, relates an atmospheric pressure ratio to the equivalent thickness of an atmospheric layer considering the layer mean of virtual temperature, gravity, and occasionally wind. It is derived from the hydrostatic equation and the ideal gas law.