Search results
Results From The WOW.Com Content Network
Scale height. The earth atmosphere's scale height is about 8.5 km, as can be confirmed from this diagram of air pressure p by altitude h: At an altitude of 0, 8.5, and 17 km, the pressure is about 1000, 370, and 140 hPa, respectively. In atmospheric, earth, and planetary sciences, a scale height, usually denoted by the capital letter H, is a ...
The nanometre ( SI symbol: nm) is a unit of length in the metric system equal to 10−9 metres ( 1 1 000 000 000 m = 0.000 000 001 m ). To help compare different orders of magnitude, this section lists lengths between 10 −9 and 10 −8 m (1 nm and 10 nm). 1 nm – diameter of a carbon nanotube.
Earth's rotational velocity also varies in a phenomenon known as length-of-day variation. [170] Earth's annual orbit is elliptical ... with a scale height of about 8. ...
The precise strength of Earth's gravity varies with location. The agreed upon value for standard gravity is 9.80665 m/s 2 (32.1740 ft/s 2) by definition. [ 4] This quantity is denoted variously as gn, ge (though this sometimes means the normal gravity at the equator, 9.7803267715 m/s 2 (32.087686258 ft/s 2 )), [ 5] g0, or simply g (which is ...
The curvature of the Earth is evident in the horizon across the image, and the bases of the buildings on the far shore are below that horizon and hidden by the sea. The simplest model for the shape of the entire Earth is a sphere. The Earth's radius is the distance from Earth's center to its surface, about 6,371 km (3,959 mi). While "radius ...
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, [23] with some variation due
An Earth ellipsoid or Earth spheroid is a mathematical figure approximating the Earth's form, used as a reference frame for computations in geodesy, astronomy, and the geosciences. Various different ellipsoids have been used as approximations. It is a spheroid (an ellipsoid of revolution) whose minor axis (shorter diameter), which connects the ...
Air mass (astronomy) In astronomy, air mass or airmass is a measure of the amount of air along the line of sight when observing a star or other celestial source from below Earth's atmosphere ( Green 1992 ). It is formulated as the integral of air density along the light ray . As it penetrates the atmosphere, light is attenuated by scattering ...