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The variation in temperature that occurs from the highs of the day to the cool of nights is called diurnal temperature variation. Temperature ranges can also be based on periods of a month or a year. The size of ground-level atmospheric temperature ranges depends on several factors, such as: Average air temperature; Average humidity; The regime ...
Density and pressure decrease smoothly with altitude, but temperature (red) does not. The speed of sound (blue) depends only on the complicated temperature variation at altitude and can be calculated from it since isolated density and pressure effects on the speed of sound cancel each other. The speed of sound increases with height in two ...
A wind speed gradient of 4 (m/s)/km can produce refraction equal to a typical temperature lapse rate of 7.5 °C/km. [51] Higher values of wind gradient will refract sound downward toward the surface in the downwind direction, [52] eliminating the acoustic shadow on the downwind side. This will increase the audibility of sounds downwind.
This increase of temperature with altitude is characteristic of the stratosphere; its resistance to vertical mixing means that it is stratified. Within the stratosphere temperatures increase with altitude (see temperature inversion); the top of the stratosphere has a temperature of about 270 K (−3°C or 26.6°F). [9] [page needed]
The speed of sound (blue) depends only on the temperature variation at altitude (red) and can be calculated from it since isolated density and pressure effects on the speed of sound cancel each other. The speed of sound increases with height in two regions of the stratosphere and thermosphere, due to heating effects in these regions.
Atmospheric density decreases as the altitude increases. This variation can be approximately modeled using the barometric formula. More sophisticated models are used to predict the orbital decay of satellites. The average mass of the atmosphere is about 5 quadrillion (5 × 10 15) tonnes or 1/1,200,000 the mass of Earth.
a lapse rate given per kilometer of geopotential altitude (A positive lapse rate (λ > 0) means temperature increases with height) In the above table, geopotential altitude is calculated from a mathematical model that adjusts the altitude to include the variation of gravity with height, while geometric altitude is the standard direct vertical ...
Comparison of the 1962 US Standard Atmosphere graph of geometric altitude against air density, pressure, the speed of sound and temperature with approximate altitudes of various objects. [ 1 ] The U.S. Standard Atmosphere is a static atmospheric model of how the pressure , temperature , density , and viscosity of the Earth's atmosphere change ...