The Corona effect
StefanLaserScience-study wise, it's interesting to see that based on sensing and modelling scientists find it challenging to carve out a "Corona effect". The weather is just very unique this year. However, a new assessment by the German Aerospace Center claims to have "proven" it. In the Italian Lombardai (the North), for example, the effect boils down to 45 percent. This is the main finding of this link (which has some nice gifs, but otherwise is written in German).