The Green Flash and Other Low Sun Phenomena

40 cm refractor 80 km distant actual sunsets ARROW SHOWS DIRECTION blind strip blue flash BSAF Castel Gandolfo chronograph colour photographs DIRECTION OF SUNSET discontinuity layers distant sea horizon Ektachrome daylight emerald green exposure flash at sunrise focal length green flash Green Ray green rim green segment green strips haze horizon h humid influence intense green inversion layers JBAA Km distant Cagliari-Elmas km distant horizon km distant sea Kodachrome layers of discontinuity Le rayon vert Leica light low sun lower rim metre refractor minutes before sunset neutral filter Note Observatory observed PASP Payerne photographs were taken plates rayon vert red flash red rim reflector refraction refractor f reproduced Rocca Priora scintillation scintillation effects seconds seen setting sun spectrum Sun's diameter sun's disc sun's rim sunspots Taken with 40 temp temperature inversion Tolfa TREUSCH Vatican Observatory vertical visually wind yellow z'so zenith distance