© George Anderson
Reading, United Kingdom of Great Britain and Northern Ireland
Latitude: 51° 27' 41'' N
Longitude: 0° 57' 58'' W
23 December 2007 1500 (Local Time)
Camera direction: towards W
Image P/S code: P.11.1.1
Image I.D.: 4697
Fog is a suspension of very small, usually microscopic water droplets in the air, reducing visibility at the Earth's surface. The term is used when the horizontal visibility is reduced to less than 1 km. In this picture the visibility is only about 100 m.
The reduction in visibility depends on the structure of the fog, and especially on the number density and size distribution of the droplets. The structure may vary a great deal in time and space. However, in this particular example on the banks of the River Thames in Reading, England, UK at 1500 hours in the afternoon, the visibility changed only slowly and the fog persisted throughout the day.
A ridge of high pressure extended over southern England from an anticyclone centred over continental Europe.
Links in the image description will highlight features on the image. Mouse over the features for more detail.