Contour line future weather patterns. Isobars are commonly used in television weather reporting. Isallobars are lines joining points of equal pressure change during a specific time interval. These can be divided into "anallobars", lines joining points of equal pressure increase during a specific time interval, and "katallobars", lines joining points of equal pressure decrease. In general, weather systems move along an axis joining high and low isallobaric centers. Isallobaric gradients are important components of the wind as they increase or decrease the geostrophic wind. An isopycnal is a line of constant density. An "isoheight" or "isohypse" is a line of constant geopotential
Newmark's influence chart surface, and q = the load per unit area applied at the surface. Using the pressure ratios obtained from the equation above, he was able to form the influence chart. The chart is constructed by drawing concentric circles. The circles are divided by equally spaced radial lines. The radii of the circles are equal to the R/z values corresponding to F U K〖∆σ〗_z/q = 0, 0.1, 0.2,…,1. There are nine circles shown since when 〖∆σ〗_z/q = 0, R/z = 0 also. The unit length for plotting the circles is AB. When solving a vertical stress problem using Newmark’s influence chart,