Deformation (meteorology)

Deformation is the rate of change of shape of fluid bodies. Meteorologically, this quantity is very important in the formation of atmospheric fronts, in the explanation of cloud shapes, and in the diffusion of materials and properties.

The deformation of horizontal wind is defined as ${\displaystyle \operatorname {def} \mathbf {V} ={\sqrt {A^{2}+B^{2}}}}$, where ${\displaystyle \ A={\frac {\partial v}{\partial x}}+{\frac {\partial u}{\partial y}}}$ and ${\displaystyle \ B={\frac {\partial u}{\partial x}}-{\frac {\partial v}{\partial y}}}$, representing the derivatives of wind component. Because these derivatives vary greatly with the rotation of the coordinate system, so do ${\displaystyle \ A}$ and ${\displaystyle \ B}$.

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