  Solar "magnetic tornadoes" are produced by rotating magnetic field structures
that extend from the upper convection zone and the photosphere to the corona of
the Sun. Recent studies show that such rotating features are an integral part
of atmospheric dynamics and occur on a large range of spatial scales. A
systematic statistical study of magnetic tornadoes is a necessary next step
towards understanding their formation and their role for the mass and energy
transport in the solar atmosphere. For this purpose, we have developed a new
automatic detection method for chromospheric swirls, i.e. the observable
signature of solar tornadoes or, more generally, chromospheric vortex flows and
rotating motions. Unlike the previous studies that relied on visual
inspections, our new method combines a line integral convolution (LIC) imaging
technique and a scalar quantity which represents a vortex flow on a
two-dimensional plane. We have tested two detection algorithms, based on the
enhanced vorticity and vorticity strength quantities, by applying them to 3D
numerical simulations of the solar atmosphere with CO5BOLD. We conclude that
the vorticity strength method is superior compared to the enhanced vorticity
method in all aspects. Applying the method to a numerical simulation of the
solar atmosphere revealed very abundant small-scale, short-lived chromospheric
vortex flows that had not been found by visual inspection before.
