L’OPOD di oggi ci mostra delle iridescenze formatesi sulla scia di condensazione di un Singapore Airlines B777 a 34.000 piedi, la foto ci arriva da Adeel Shafiq
Ecco la spiegazione dell’autore: “Aircraft contrails have two sources. The major one is water droplets condensed from water vapour generated in the engines. Combustion of aviation fuel gives water vapour, carbon dioxide and traces of NOx and soot. The second generator is water vapour already in the air condensed to droplets by airflow over the fuselage and wings. Air passing over the top of wings or convex fuselage sections travels faster, expands and cools. Sometimes, if the air is sufficiently humid, water vapour then condenses out into a fine droplet mist. The iridescent colours are produced by individual water droplets diffracting sunlight. When the droplets are locally of similar size they all diffract their coloured light into the same direction and so colours become evident to us. (via Soumyadeep Mukherjee and Les Cowley, Atmospheric Optics)“.
Rubrica curata da Marco Meniero e Marcella Botti per conto del #GrAG
Per approfondire i testi sulle fotometeore:
https://www.meniero.it/blog-ultimo-articolo/post/218498/testi-consigliati-sulle-fotometeore
#fotometeore #opod #opodGRAG #nightscape #cloudy #dawn #horizon #photooftheday #skies #sunrays #sunrise #luciecoloridelcielo #sunsetlovers #splendid_horizon #igsilhouette #sunset_stream #beautifulearth #landacape #sun #light #exploringtheglobe #earthfever #earthofficial #sky
