# Math Insight

### Image: Microscopic circulation is induced by changes of the vector field

The circle with center fixed will tend to rotate in a counterclockwise direction if $\dlvfc_2$ (in red) is larger to its right or if $\dlvfc_1$ (in blue) is larger below. This picture gives intuition why changes in the vector field components lead to circulation and that the formula for microscopic circulation is $\pdiff{\dlvfc_2}{x}-\pdiff{\dlvfc_1}{y}$.

Source image file: microscopic_circulation_vector_field_change.svg
Source image type: Inkscape SVG