This hoar frost on the Manorburn dam in Central Otago is caused by freezing fog. If the air temperature of a fog is below 0° C then the tiny water droplets remain in a liquid form. But if they come into contact with objects such as trees and leaves they freeze, covering surfaces with rime – known as a hoar frost.
Te whakamahi i tēnei tūemi
Otago Daily Times
Reference: 28 June 2006, p. 17
Photograph by Gerard O'Brien
Permission of the Otago Daily Times must be obtained before any re-use of this image.