Explorer - Hummm….I’m not entirely sure how to respond.
Regardless of the vortex…and regardless of where (ie. Earth, Mars, etc.) they all operate the same in terms of how they are created. Atmospheric vortex’s (tornadoes, dust devils, gustnado’s, fire whirls, etc., etc.) are all caused due to localized differences in temperature and atmospheric pressures, which under the right conditions will cause rotation.
Exactly what edge characteristics, based on your observations, do you dispute?
Dust Devils are typically found in exceedingly hot, flat, barren areas…such as the US Southwest, or say portions of Australia. While not impossible, I’d say their occurrence in the UK is slim…I’d think something more along the lines of a sheer funnel.
Hurricane’s are excellent examples…they are not a 100% self contained storm system; that is to say wind gradually increases as the storm approaches. It is not, as a “cookie cutter” would suggest, a sudden 0 to +100mph difference in wind. Collateral damage, such as downed trees, occur well beyond the center of the storm.
Tornados, dust devils, etc. all work basically the same way, just on much smaller scale.
Consider this; it is a dust devil as photographed by the Mars rover Spirit.
You’ll note that the center of the vortex is dense (from dust); that density dissipates over distance from the center. Why; because the rotation (ie. “wind”) is weaker on the further you move away from the center.…if it were a “cookie cutter”, the vortex would appear far more universal in terms of density over its span, and suddenly stop along its edge. It would be like watching a solid object simply move along.
Still using the example from Mars, you'll note the "updraft" effect...that is to say, where do you think all that dust came from to start with? The "updraft" of the vortex pulled the dust from the ground.
I submit for a crop circle to have been formed by a atmospheric event, there would HAVE to be signs of collateral damage in the field….but there never is; you are left with virtually perfect circles and elaborate designs. A wind so strong as to completely bend over a stalk, yet leave one next to it 100% untouched? No signs of the "updraft" effect?
All that said...along the lines of what Cuddles said....what do YOU think causes crop cricles, what is YOUR evidence?