Early morning mirages that occurred in the freezing eastern Hokkaido city of Kushiro on January 10 and 11 changed views of streetscapes, making circular gas tanks resemble the shape of darumas (Japanese tumbler dolls).

The mirage is a phenomenon that occurs due to the refraction of light at the edges of layers of air made up of different temperatures. The ground surface was deprived of heat due to severe cold temperatures and radiative cooling, with this season’s lowest temperature of minus 18.9 degrees recorded on consecutive days on the 10th and 11th. A layer of freezing air formed near the ground surface, with virtual images – known as ‘superior mirages’ – appearing over the real images of gas tanks, hotels and the like.

According to the Japan Mirage Association, “Superior mirages caused by radiative cooling are rare. Perhaps people can search for places that look different among familiar landscapes”.