Solitary vortex solutions in a sheared and differentially heated vertical fluid layer with stable stratification

Solitary vortex solutions in a sheared and differentially heated vertical fluid layer with stable stratification have been found. For certain parameter combinations the solitary vortices coexist with the linearly stable base flow. First stability calculations suggest linear instability of the solitary solutions. Nevertheless the solitary states might play a role in the transition process of free convection and could be related to the still poorly understood strongly localized vortices that have been reported to appear transiently in experiments and direct numerical simulations.