On the Sensitivity of the Wind Field Relative to Pressure Variations

It is assumed that the motion is frictionless and adiabatic but not necessarily horizontal. A geostrophic approximation of second order is introduced, and a measure of the sensitivity of the wind field relative to pressure variations is obtained. It is shown that the sensitivity depends essentially upon the lateral shear of the geostrophic wind and the tangential and orthogonal curvature of the geostrophic streamlines. In particular, when the geostrophic wind is large, the effect of the orthogonal curvature is predominant.