Alps and Valley Fog

January 14, 2010

20100114 – Thursday - Alps and Valley Fog

Photographer: Stefano De Rosa
Summary Authors: Stefano De Rosa; Jim Foster

January 2010 Earth Science Picture of the Day Viewer's ChoiceThe photo above showing a stunning view of the Italian Alps and the fog carpeted Po River valley was taken on December 23, 2009. The city of Turin is completely enshrouded by this foggy layer (radiation or valley fog). Air cooled by re-radiation of heat from the valley floor on clear nights results in fog if the air temperature drops to the dew point temperature. Note the plume rising from the center of the valley, punching through the optically thick but physically thin fog. The plume is likely from a power plant or an industrial facility.

Turin coordinates: 45.066667, 7.7