Vortical structures in convective boundary layers and implications for the initiation of deep convection

The vertical and horizontal structure of dust devil-scale vertical vortices and the parent-scale circulations in which they are observed to be embedded in the convective boundary layer are presented. These findings suggest that although dust devil-scale vortices are typically shallow phenomena, they, and their invisible counterparts, may act as “feeder” eddies of heat and momentum to the larger scale thermal plumes in which they are embedded. It is shown that the disturbed wind fields associated with dust devils can be up to ten times the radius of the dust column itself and extend 1-2 km higher than the visible dust column. Evidence is given that indicates that the upper portions of dust devil circulations may be analogous to misocyclones. If this is indeed the case, dust devils may act as markers for larger scale vertical vortices in the boundary layer and may have more direct implications for vertical transport and thus, initiation of deep convection.