On the phenomenon of the blue sun: Nellie Wullenweber,Anna Lange,Alexei Rozanov,and Christian von Savigny “This study examines the cause of the blue colour of the sun as observed after the eruption of Krakatao in 1883 as well as other volcanic eruptions or massive forest fire events. Aerosol particles, e.g. volcanic ash or products of biomass burning, are believed to be able …