Related Words

Isobar: The line drawn on a weather map connecting points of equal barometric pressure.

Isobarik: Sometimes spelled Isobaric, this is an enclosure design in which two or more Drivers are coupled together by a sealed air mass to operate as a single driver. With proper sealing and design, . . . View Full Definition

Isobaric: Having constant pressure.

Geopotential Anomaly: The excess in geopotential difference over the standard geopotential difference [at a standard specific volume at 35 parts per thousand (‰) and 0 degrees C] between isobaric surfaces. See ge . . . View Full Definition

Level Of No Motion: A level (or layer) at which it is assumed that an isobaric surface coincides with a geopotential surface. A level (or layer) at which there is no horizontal pressure gradient force.

Geopotential Topography: The topography of an equiscalar (usually isobaric) surface in terms of geopotential difference. As depicted on maps, isopleths are formed by the intersection of the isobaric surface with a s . . . View Full Definition

Tropical Depression: A tropical cyclone in which the maximum sustained surface winds are 38 miles per hour (33 knots) or less. Characteristically having one or more closed isobars, it may form slowly from a trop . . . View Full Definition

Closed Low: A region of low pressure distinguished by a center of counterclockwise circulation (in the Northern Hemisphere), and is surrounded by one or more isobars or height contours. Closed lows alof . . . View Full Definition

Friction Layer: The thin layer of atmosphere adjacent to the earth's surface. Surface friction is effective in slowing down wind up to approximately 1,500 to 3,000 feet above the ground. Above this level, a . . . View Full Definition

Geostrophic Wind: A steady horizontal motion of air along straight, parallel isobars or contours in an unchanging pressure or contour field. It is assumed that there is no friction, that the flow is straight . . . View Full Definition