Photographer: Tero Marin
Summary Authors: Tero Marin; Jim Foster
Featured above are a colorful sunrise and an inferior mirage as observed from Emäsalo, Porvoo, Finland. In order to see a mirage the temperature gradient near the surface cannot be flat. More remarkable thermal gradients (or inversions) are required for a mirage to be noticed. Here, rays of light from the rising Sun are refracted by layers of air in such a way that they appear to be coming from below the horizon, with the result that the wooded island at center, as well as the lands flanking it, seem to be floating. The illustration at left gives more detail of my view. Photo taken 7:12 a.m. March 5, 2017. Meteorological data: Surface air temperature of 19 F (-7 C), calm winds.
Photo Details: Nikon D810 camera; 600 mm lens; f36; 1/100 sec. exposure; ISO 3200; tripod.
