2.1 Vertical and horizontal pressure gradients in hydrostatic equilibrium At height = 800m the pressure is 950hPa. The top heights and the densities at the centers of the layers at horizontal positions x1 1km and x2 = 2km are given in table 1. Assume the density to be constant within each layer. Calculate the pressure difference between top and bottom of each layer and calculate the resulting pressure at layer boundaries of each layer.