Measurement of Tsukuba tornado with particle image velocimetry

The present analytical study aims to clarify the velocity fields around Tsukuba tornado occurred 6 May 2012. The three-dimensional location and position of Tsukuba tornado were measured from more than two pictures of funnel cloud taken from the different points, by using a computer vision technique. The tangential velocity of Tsukuba tornado was also measured from the motion of debris image by using a particle image velocimetry as shown in the figure. The velocity and location of Tsukuba tornado were compared with those obtained by the C-band polarimetric Doppler radar of Meteorological Research Institute.