It is shown that placing a Kirchhoff vortex in a weak resonant strain having uniform, but oscillating strain rate with chirped oscillation frequency, allows adiabatic control of the axis ratio r = a/b and rotation phase of the vortex. The
phenomenon has a threshold on the amplitude of oscillations of the strain rate and is due to the persisting nonlinear
phase locking (autoresonance) between the elliptic vortex and the adiabatically varying straining flow.

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