CAVE-ART Identification of Polar Vortices

• Main Author: Lawrence, Zachary D.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Copernicus Publications 2016
• Subjects: Earth Sciences; Arctic; Stratosphere; Polar vortex; Final warming; Ozone loss; Canada; Merra
• Online Access: https://dx.doi.org/10.5446/20953; https://av.tib.eu/media/20953

Supplementary animation for: "The major stratospheric final warming in 2016: Dispersal of vortex air and termination of Arctic chemical ozone loss" Authors: Gloria L. Manney, and Zachary D. Lawrence Journal: Atmospheric Chemistry and Physics (ACP) This animation demonstrates how CAVE-ART (see main text) identifies individual polar vortex regions during the 2016 Arctic major final warming. The greyscale and red background field is scaled potential vorticity (sPV) from MERRA-2 at 490 (left) and 850 K (right). The purple contour lines represent the vortex edges as “seen” by CAVE-ART after filtering out extraneous small regions. The vortex equivalent ellipses plotted are derived from the 2D moment diagnostics (see main text) incorporated into CAVE-ART, and are shown with numeric labels plotted at the location of the vortex centroids. Note that in cases when individual vortex regions are very small or distorted, it is possible for 1) the centroids to fall completely outside the vortex region, and/or 2) the equivalent ellipse to not fit the vortex region very well (see, for example, the pieces of the vortex “tail” at 850 K around 11 Mar 2016, ~26 seconds into video). Also note that CAVE-ART filters out any individual high sPV regions (i.e., sPV above the the vortex edge value) having an equivalent latitude greater than 84 degrees, corresponding to an area less than roughly 0.5% of a hemisphere. This is the reason why regions can seem to die out too early (see, for example, the vortex labeled 3 at 490 K around ~31 seconds into video, which moves over Canada and repeatedly goes above/below the area threshold, taking on labels 4 through 8).