DrJOne of the weirdest atmospheric things I have encountered in 25+ year of atmospheric research: a 1-2 km thick SO2-filled stratospheric structure a few 100s km in diameter surviving for months in an otherwise disruptive environment. We wrote about it https://rdcu.be/c2kig🧵
The June 2018 explosive eruption of the #Raikoke volcano injected large amounts of volcanic material directly into the stratosphere. Embedded were two circular structures that remained intact for months. At some point one transferred from the northern Pacific to the subtropics.
Several publications explored this episode trying to answer the question how it could maintain its integrity, but without definitive answers. Was it a "dead fish", passively floating around with the background flow, or was there some dynamical confinement at play?
Our hunch - for a variety of reasons - was the latter. Model simulations (trajectories or chemistry-transport) were mostly incapable of keeping things together, indicative of the destructive hostile environment. When looking into other satellite data and weather reanalyses ...
... we found many indications pointing to a type of dynamical confinement and self lofting. Key here was @esa's #AEOLUS satellite which revealed that this was a rotating disc. The rotation - potential vorticity anomaly - in the stable stratosphere prevents mixing ...
A not unknown fluid dynamical phenomenon but to our knowledge never observed before in Earth's atmosphere. Its presence raises many more questions for future research. See further our paper, with most kudos going to the colleagues of LATMOS/IPSL in Paris. https://rdcu.be/c2kig