density altitude
61delta ratio — The ratio of the takeoff ground or water run distance to the total distance over a 50 ft obstacle. This ratio, for a given aircraft, remains relatively constant regardless of the takeoff weight, density altitude, wind, etc. It is used to… …
62hovering in ground effect — A helicopter hovering at a height that is equal to or less than the span of its rotors. A helicopter can hover in ground effect at a higher density altitude than it can hover out of ground effect. A helicopter requires less power to hover in… …
63Outer space — For other uses, see Outer space (disambiguation). The boundaries between the Earth s surface and outer space, at the Kármán line, 100 km (62 mi) and exosphere at 690 km (430 mi). Not to scale Outer space is the void that exists beyond any… …
64ionosphere and magnetosphere — ▪ atmospheric science Introduction regions of Earth s (Earth) atmosphere in which the number of electrically charged particles ions (ion) and electrons (electron) are large enough to affect the propagation of radio waves (electromagnetic… …
65Polar wind — is the permanent outflow of ionization from the polar regions of the magnetosphere. [http://amsglossary.allenpress.com/glossary/browse?s=p p=43 AMS Glossary] ] Ionospheric Plasma SourceThe ‘ground state’ of the ionosphere consists of the baseline …
66Atmosphere of Earth — Air redirects here. For other uses, see Air (disambiguation). Qualities of air redirects here. It is not to be confused with Air quality …
67Atmospheric models — Static atmospheric models describe how the ideal gas properties (namely: pressure, temperature, density, and molecular weight) of an atmosphere change, primarily as a function of altitude. For example, the US Standard Atmosphere is essentially a… …
68Space debris — populations seen from outside geosynchronous orbit (GEO). Note the two primary debris fields, the ring of objects in GEO, and the cloud of objects in low earth orbit (LEO) …
69glacier — glaciered, adj. /glay sheuhr/, n. an extended mass of ice formed from snow falling and accumulating over the years and moving very slowly, either descending from high mountains, as in valley glaciers, or moving outward from centers of… …
70Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
