Francisco Javier Beron-Vera

We identify materially defined regions in unsteady two-dimensional flows that combine finite-time contraction with elevated accumulated intrinsic rotation along trajectories, which we term Lagrangian rotating contracting structures. These regions are detected using existing objective diagnostics—the Lagrangian-averaged vorticity deviation (LAVD) together with direct tests of material contraction—without relying on the geometry of LAVD level sets. In strongly deforming flows, LAVD maxima need not correspond to vortical regions or be enclosed by regular level sets, rendering geometry-based identification unreliable. Nevertheless, regions exhibiting inward spiraling motion and contraction can be extracted by combining LAVD with a contraction criterion. Applications to atmospheric and oceanic flows show that such behavior arises both in twisted LAVD fields generated at submesoscales and in mesoscale flows where it is enhanced by inertial effects, with finite-time contraction providing the dynamical constraint that isolates materially organized regions with elevated intrinsic rotation.

Pyro-cumulonimbus convection associated with extreme wildfires can generate longlived vortical structures in the stratosphere. These structures have been described as coherent, yet a rigorous material characterization has remained lacking. Here we provide such a characterization by applying geodesic vortex detection to reanalysis winds during the 2019–2020 Australian bushfires. We identify a coherent Lagrangian vortex, dubbed Koobor, whose boundary is given by materially coherent loops exhibiting nearly uniform stretching and strong resistance to filamentation over finite time intervals of up to 40 days. The detected vortex extends across multiple isentropic levels, revealing a vertically organized evolution with delayed onset and reduced persistence at higher levels. Taken together across isentropic levels, the reconstructed life cycle indicates that Koobor maintained quasi-material coherence for nearly 60 days from its first detection, through a sequence of overlapping materially coherent boundaries rather than a single boundary advected over the entire period. Our results establish a material framework for wildfire-induced stratospheric vortices and provide a dynamically consistent description of their life cycle, from formation to decay

Pyro-cumulonimbus convection associated with extreme wildfires can generate longlived vortical structures in the stratosphere. These structures have been described as coherent, yet a rigorous material characterization has remained lacking. Here we provide such a characterization by applying geodesic vortex detection to reanalysis winds during the 2019–2020 Australian bushfires. We identify a coherent Lagrangian vortex, dubbed Koobor, whose boundary is given by materially coherent loops exhibiting nearly uniform stretching and strong resistance to filamentation over finite time intervals of up to 40 days. The detected vortex extends across multiple isentropic levels, revealing a vertically organized evolution with delayed onset and reduced persistence at higher levels. Taken together across isentropic levels, the reconstructed life cycle indicates that Koobor maintained quasi-material coherence for nearly 60 days from its first detection, through a sequence of overlapping materially coherent boundaries rather than a single boundary advected over the entire period. Our results establish a material framework for wildfire-induced stratospheric vortices and provide a dynamically consistent description of their life cycle, from formation to decay

Pyro-cumulonimbus convection associated with extreme wildfires can generate longlived vortical structures in the stratosphere. These structures have been described as coherent, yet a rigorous material characterization has remained lacking. Here we provide such a characterization by applying geodesic vortex detection to reanalysis winds during the 2019–2020 Australian bushfires. We identify a coherent Lagrangian vortex, dubbed Koobor, whose boundary is given by materially coherent loops exhibiting nearly uniform stretching and strong resistance to filamentation over finite time intervals of up to 40 days. The detected vortex extends across multiple isentropic levels, revealing a vertically organized evolution with delayed onset and reduced persistence at higher levels. Taken together across isentropic levels, the reconstructed life cycle indicates that Koobor maintained quasi-material coherence for nearly 60 days from its first detection, through a sequence of overlapping materially coherent boundaries rather than a single boundary advected over the entire period. Our results establish a material framework for wildfire-induced stratospheric vortices and provide a dynamically consistent description of their life cycle, from formation to decay

Pyro-cumulonimbus convection associated with extreme wildfires can generate longlived vortical structures in the stratosphere. These structures have been described as coherent, yet a rigorous material characterization has remained lacking. Here we provide such a characterization by applying geodesic vortex detection to reanalysis winds during the 2019–2020 Australian bushfires. We identify a coherent Lagrangian vortex, dubbed Koobor, whose boundary is given by materially coherent loops exhibiting nearly uniform stretching and strong resistance to filamentation over finite time intervals of up to 40 days. The detected vortex extends across multiple isentropic levels, revealing a vertically organized evolution with delayed onset and reduced persistence at higher levels. Taken together across isentropic levels, the reconstructed life cycle indicates that Koobor maintained quasi-material coherence for nearly 60 days from its first detection, through a sequence of overlapping materially coherent boundaries rather than a single boundary advected over the entire period. Our results establish a material framework for wildfire-induced stratospheric vortices and provide a dynamically consistent description of their life cycle, from formation to decay

Pyro-cumulonimbus convection associated with extreme wildfires can generate longlived vortical structures in the stratosphere. These structures have been described as coherent, yet a rigorous material characterization has remained lacking. Here we provide such a characterization by applying geodesic vortex detection to reanalysis winds during the 2019–2020 Australian bushfires. We identify a coherent Lagrangian vortex, dubbed Koobor, whose boundary is given by materially coherent loops exhibiting nearly uniform stretching and strong resistance to filamentation over finite time intervals of up to 40 days. The detected vortex extends across multiple isentropic levels, revealing a vertically organized evolution with delayed onset and reduced persistence at higher levels. Taken together across isentropic levels, the reconstructed life cycle indicates that Koobor maintained quasi-material coherence for nearly 60 days from its first detection, through a sequence of overlapping materially coherent boundaries rather than a single boundary advected over the entire period. Our results establish a material framework for wildfire-induced stratospheric vortices and provide a dynamically consistent description of their life cycle, from formation to decay

Pyro-cumulonimbus convection associated with extreme wildfires can generate longlived vortical structures in the stratosphere. These structures have been described as coherent, yet a rigorous material characterization has remained lacking. Here we provide such a characterization by applying geodesic vortex detection to reanalysis winds during the 2019–2020 Australian bushfires. We identify a coherent Lagrangian vortex, dubbed Koobor, whose boundary is given by materially coherent loops exhibiting nearly uniform stretching and strong resistance to filamentation over finite time intervals of up to 40 days. The detected vortex extends across multiple isentropic levels, revealing a vertically organized evolution with delayed onset and reduced persistence at higher levels. Taken together across isentropic levels, the reconstructed life cycle indicates that Koobor maintained quasi-material coherence for nearly 60 days from its first detection, through a sequence of overlapping materially coherent boundaries rather than a single boundary advected over the entire period. Our results establish a material framework for wildfire-induced stratospheric vortices and provide a dynamically consistent description of their life cycle, from formation to decay