Characterizing Stratospheric Polar Vortex Variability with Computer Vision Techniques

The Northern Hemisphere (NH) stratospheric polar vortex exhibits a wide range of interannual variability that can influence polar chemical processing, ozone depletion, and tropospheric weather and climate. Recently there has been a renewed interest in understanding and utilizing the full spectrum of polar vortex variability, including sudden warmings, strong vortex events, etc., because of the connections to tropospheric weather and climate on seasonal and sub-seasonal timescales. Here we present results from the Characterization and Analysis of Vortex Evolution using Algorithms for Region Tracking (CAVE-ART) package, which uses computer vision techniques to comprehensively characterize the three dimensional evolution of the polar vortex throughout the stratosphere. We will give a summary of the techniques that allow us to identify specific geometrical and dynamical polar vortex characteristics, including the evolution of individual offspring vortices during vortex-split events. Furthermore, we will show examples and applications of CAVE-ART using the full record of NH winters in the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2).