Impact of the northern polar vortex and geomagnetic activity on solar radiation at surface and solar power production in Europe

Abstract Energy production by solar panels depends directly on the amount of incoming solar radiation at the surface. During winter, the weather in Europe is strongly influenced by the polar vortex, a westerly wind system circulating around the polar region in the stratosphere and mesosphere. A strong vortex typically brings warm and cloudy conditions to northern Europe, while southern Europe experiences clearer skies and colder weather. The state of the polar vortex is modulated by factors such as energetic electron precipitation (EEP) from space and planetary waves propagating toward the polar region. In this study, we investigate how the strength of the polar vortex affects wintertime cloud cover, surface incoming solar radiation, and solar power production across Europe. We show that strong vortex and increased EEP are linked with decreased cloud cover and increased solar power production in southern Europe, when the quasi-biennial oscillation is in its easterly phase. We find a particularly strong influence in Spain, which we examine in more detail.