Polar Vortex Strengthens as El Niño Signals Mid-Winter Weakening
According to NASA Ozone Watch data, the Northern Hemisphere stratospheric polar vortex returned to westerly circulation over the Arctic in late August 2026 and strengthened through the first half of September as seasonal cooling set in. Zonal-mean winds at 60° north and 10 hPa reached 10.40 m/s on September 15, surpassing the 8.10 m/s climatological … Read more