Well strange anyway if things become non disclosed don't bother more speculations..
In this way, why you tried a link with the Rayleigh plasma which runs at very lower pressure ?
The scale is a bit misleading, yes.
The blue region, below atmospheric pressure (zero Pa), is on a different scale to the region above atmospheric pressure.
Lowest pressure is only 0,035 Pa below atmospheric (so hardly any depression)
The highest pressure, at the periphery, is 1100 Pa above atmospheric.
This is still not a particularly high pressure (0.011 bar, gauge) - but air is not particularly dense, and 20 m/s at a radius of 100 mm isn't particularly fast.