Northern Lights Dynamics Suggests Polar Vortex Is Breaking Up Again

The Space Climate Research Group at the University of Oulu, Finland, has for some time been studying the effects of energetic particle precipitation from space, more commonly known as the Northern Lights or Aurora Borealis, on weather variations winter. The Northern Lights are not only a magnificent light phenomenon, but also involve chemical changes that lead to the depletion of the ozone layer in the polar stratosphere in winter.

Ozone depletion caused by energetic particles intensifies the polar vortex, a strong wind that blows from west to east around the polar region during the winter season. The intensification of the polar vortex also strengthens westerly winds at the surface, producing mild winters in northern Europe and Finland in particular.

“On the other hand, during winters with low particle precipitation, the polar vortex can weaken and even break up completely, allowing cold Arctic air to flow southward. This is when Finland and Northern Europe usually experience cold spells, like this winter,” explains Associate Professor Timo Asikainen.

“The polar vortex has already broken once this winter and is expected to break again this coming weekend. Our own models already predicted last summer the probable breakup of the polar vortex during the winter.”

Experience shows that, particularly in Finland, the consumption of electricity and, more generally, of energy used for heating, depends to a large extent on weather conditions. This raises the question: to what extent can particle precipitation from space affect electricity consumption via the polar vortex? A recent study by the Space Climate Group at the University of Oulu was the first to address this question.

The study, published in Scientific reportsfound a significant influence of particle precipitation on winter temperatures in Finland and on the temperature-dependent share of electricity consumption during the winter period (January–March).

At best, the variability associated with energetic particle precipitation accounted for about 14% of the average level of electricity consumption in Finland in winter and explained up to 50% of the interannual variations in electricity consumption.

“The most significant result of the study showed that particle precipitation, or geomagnetic activity as a proxy, significantly influences Finland’s winter temperatures and electricity consumption across the polar vortex: heavy precipitation of particles correspond to higher winter temperatures and lower electricity consumption, and vice versa,” says doctoral student Veera Juntunen.

The study used comprehensive statistics on electricity consumption from the 1990s to the present, provided by the Finnish Energy Association. “From these data, we had to carefully remove variations not related to temperatures. This then revealed the influence of particle precipitation on temperature and power consumption,” explains Juntunen.

The connection was valid from the 1950s to the present, but interestingly only during winters, when equatorial stratospheric winds, called QBO winds, blow from the east.

“This QBO effect has already been observed in previous studies and is linked to the fact that when QBO winds blow eastward, large-scale atmospheric waves, called planetary waves, are guided from the lower atmosphere to the polar stratosphere. There, with the precipitation of the particles, they create the effect observed on the polar vortex,” explains Asikainen.

The study reveals an interesting new societal influence of space weather. Taking into account particle precipitation from space could help predict winter temperatures and electricity consumption, in the best case, several months or even years in advance, if we learn to better predict particle precipitation on longer time scales than currently.