i·so·bar / ˈīsəˌbär/ • n. 1. Meteorol. a line on a map connecting points having the same atmospheric pressure at a given time or on average over a given period. ∎  Physics a curve or formula representing a physical system at constant pressure.2. Physics each of two or more isotopes of different elements, with the same atomic weight.DERIVATIVES: i·so·bar·ic / ˌīsəˈbarik; -ˈbär-/ adj.

isobars

isobar A line on a weather map connecting points that are at the same atmospheric pressure. On surface charts the values are ‘reduced’ to sea level. Such isolines are drawn at a given interval in millibars. Contours of isobaric surfaces may be drawn to represent surfaces in the upper atmosphere composed of points at the same pressure.

isobar Line on a weather map connecting points at the same atmospheric pressure. On surface charts the values are ‘reduced’ to sea level. Such isolines are drawn at a given interval in millibars. Contours of isobaric surfaces may be drawn to represent surfaces in the upper atmosphere composed of points at the same pressure.

isobar Line on a weather map connecting points of equal pressure, either at the Earth's surface or at a constant height above it. The patterns of isobars depict the variation in atmospheric pressure, showing areas of high and low pressure on the map.