Sudden stratospheric warming events always occur on a large scale. It is not easy to imagine them, so we sometimes have to get creative and display them in a whole new way.
Yesterday we wrote about the strong stratospheric warming over the south pole.
The visualization team at Severe Weather Europe produced a unique 3D display of the sudden stratospheric warming over the south pole, for a better understanding of its dynamics.
Here is a description of the video so you will better understand what you are looking at:
The whole box over the south pole shows the atmosphere from 12 km to 56 km altitude. The vertical scale is greatly exaggerated/expanded to better visualize the process. The red/pink 3D air mass at the top, is air with temperature of -14°C and warmer. So you only see the air mass that is warmer than -14°C, which is relatively warm for the mid-stratosphere (25 km – 38 km).
The blue 3D air mass shows air with temperature of -73°C and colder. That is usually the cold core of the polar vortex.
The 2D field on the bottom is 150 mb pressure level temperature. We recommend watching in full screen and in HD quality.
We can see very nicely how the warming moves downwards, and it pushes away the cold core of the polar vortex from Antarctica towards South America. It slowly grinds away the cold core and is pushing the cold air away from the south pole into the same region, and then onward towards south Atlantic. This is not necessarily exactly what is happening at the surface, but what we see in the animation on the 2D field on the bottom is the change of weather patterns in the top of the troposphere, which are usually followed with a response on the surface, with some time delay. On the graphic below, we can see the surface temperature anomaly forecast from the GFS model. This is of course a medium range forecast, but it serves as an idea where the cold air is moving.