Tornado’s Compressibility

An earlier fluid mechanical model of a tornado [1], that assumed constant air density, forecast a horizontal rotary wind speed that decreased inversely as the distance increased from the tornado’s central axis. Such a velocity function implies that the force of friction is zero. However, if compressibility of the air is included in the model, and everything else is kept the same, dynamics changes the velocity structure to being constant and independent of the radius. Friction is also zero in this case. Observations are needed to find out what the wind structure is doing.