While Spain was pending the rains, something strange was happening with the polar vortex

The meteorology of the month of March has been marked by the wave of storms that have left intense rains throughout the Iberian Peninsula. While many monitored attentive to the possibility that the channels overflow in their surroundings, in the high layers of the atmosphere there was an important phenomenon, the disruption of the polar vortex.

New animation. NOAA (National Oceanic and Atmospheric Administration), The agency responsible for analyzing weather and weather in the United States, has shown us the disruption of the polar vortex occurred during last March. He has done it through a new animation in which the drastic changes can be seen

The polar vortex. First of all, remember that Polar vortex It is an intense atmospheric current that transports cold air around the pole at stratosphere. In winter, the polar circle stops receiving sunlight so the air at the height of the stratosphere cools. In contrast, the warm air of sub -reliable areas continues to be tempered at these altitudes, which leads to expand north. The terrestrial rotation makes this pressure a powerful current of air that surrounds the pole in winter.

Although the current is always active, it suffers important changes throughout the year. The first change is in intensity: it is during the winter months that the winds of this current reach greater force, reaching its middle peak towards the beginning of January.

The second change is in the direction. Due to the inclination of the earth’s axis, approximately between spring and autumn, the current moves away from the pole to the torque that loses intensity because the sun enlightens the pole again, heating his stratosphere and reducing the contrast with lower latitudes. This implies that high latitudes the current stops moving from west to this but does it from this to west.

When the vortex breaks. However, the current can suffer a sudden change, a disruption. These cases are usually due to sudden stratospheric warming in the pole. This “pushes” the current out. This is what happenedexplains the NOAA, last March 9: rapid stratospheric warming generated a disruption of the current that has led her to circulate in reverse and intense in high latitudes.

Return to normal. If a disruption occurs during winter, it is common for the vortex to return to its usual circulation after one of these disruptions. If this disruption occurs during spring, it is likely that the circulation will pass to its summer shape, outside the pole.

It can be expected, due to the dates, that the evolution of the vortex now takes it back to the average. Last year We saw a vortex disruption that reversed the dominant direction of the wind in early March, however the vortex recovered its direction and intensity of these dates before reversing its spring channel.

Graph in which the speed and direction of the stratospheric wind is illustrated in the 60ºN latitude. The fine blue line marks the average evolution in the 1991-2020 period; while the thickness marks the evolution between 2024 and 2025. The shadow represents the variability observed and the pink forecasts. Laura Ciasto/NOA

“Like an atmospheric diva. ” This year the models indicate that this will not be the case, which implies that we are facing the change in earlier in the records since 1958. This concludes the “season” of activity of the polar vortex, a season marked by a high intensity circulation and important volatility. A closure that has lived up to the season, according to NOAA.

“For a good part of this winter season, the polar vortex has been strong, stretched, and not very interested in interacting with the troposphere. But like a real atmospheric diva, the polar vortex had a last ace in the sleeve, disintegrate in a spectacular way and bring with him some cold air,” NOAA itself explains in a piece in his blog dedicated to the polar vortex.

And then what? In the result of all this is that the circulation of the vortex is now maintained in northern Europe and that can reach affect weather of the continent. How this arrival will depend on factors such as the interaction between this mass of air and the troposphere or what low latitudes could reach circulation in that month of April.

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Image | NOAA