ABSTRACT
Unbalanced flow is motion which does have residual accelerations along the coordinate axes. The difference between the actual wind and the geostrophic wind is called the ageostrophic wind. Isopleths or lines of equal rate of change of pressure at a given location are called isallobars and the magnitude of the isallobaric wind can be calculated from the spacing of the isallobars in a way similar to that used to find the geostrophic wind from the spacing of the isobars. Thus, a barometer or barograph installed at a fixed location will show a trace which moves up and down the graph as the highs and lows pass over it. Divergence and convergence could perhaps be measured from actual wind observations. In dynamic meteorology we are interested in large-scale vertical motion that is on the scale of the synoptic chart. Vertical motion on this scale refers to the slow ascent or descent of air over comparatively extensive areas.
