Sudden Stratospheric Warming: Polar Vortex Breakdown

The polar vortex is a ring of powerful westerly winds that seals cold air over the winter pole in the stratosphere. When upward-propagating planetary waves break there, they decelerate the vortex through wave-mean-flow interaction — and if the forcing is strong enough, the 10 hPa zonal wind at 60°N reverses from westerly to easterly, the official criterion for a Sudden Stratospheric Warming. This simulator lets you drive that wave forcing directly: watch a ring of stratospheric air parcels displace off the pole (wavenumber 1) or split into two daughter vortices (wavenumber 2) as the wind decelerates and reverses, while the polar cap warms tens of kelvin in days from forced adiabatic descent — the same event that reorganizes the tropospheric jet stream and drives cold-air outbreaks for weeks afterward.