Novaya Zemlya Mirage Observed from Sicily, Italy
August 18, 2021
Photographer: Marcella Pace
Summary Author: Marcella Pace
Compared to the time given in almanacs, actual sunrises occur slightly earlier and sunsets a bit later. This is because almanacs don't account for atmospheric refraction. The light from the Sun and the Moon, and indeed all celestial objects, passes through multiple layers of our atmosphere before reaching our eyes. Layers of different density, pressure and temperature can alter sunrises/sunsets by more than two minutes. The altitude and latitude of the observer also affect sunrise and sunset times.
The above image sequence, taken from Sicily, Italy on May 7, 2021, results from strong atmospheric refraction. This is the Novaya Zemlya mirage, which takes its name from an archipelago in the Arctic Ocean. In 1597, the crew of Willem Barents' Dutch ship witnessed this phenomenon when their ship was entangled in the ice. It was necessary to spend the winter months in place and wait for the return of the Sun, predicted for February 8. In reality, however, because of a pronounced thermal inversion they were able to see the Sun on January 24, 15-days earlier than expected. Note that as shown above, the Sun as photographed in the last image had already set by about 3 minutes but was still visible. Click here to see a video of the complete sequence.
Photo and other details: Nikon D7100 camera; Sigma 600 mm lens. Altitude of 178 m above sea level; temperature of 18.5 C °; humidity of 84%; pressure of 1.014 mb.