Investigation of North Atlantic Fog and Development of a Marine Fog Forecast System

• Main Author: Rogers, C. W.
• Other Authors: CALSPAN CORP BUFFALO NY
• Format: Text
• Language: English
• Published: 1989
• Subjects: Meteorology; *MARINE ATMOSPHERES; *FOG; *OBSCURATION; *HAZE; BOUNDARY LAYER; DISSIPATION; RADIATION ABSORPTION; HEATING; ERRORS; SHIPBOARD; CONCENTRATION(COMPOSITION); SOLAR RADIATION; MARINE METEOROLOGY; NORTH ATLANTIC OCEAN; ADVECTION; SUMMER; OPEN WATER; TEMPERATURE INVERSION; STRATUS CLOUDS; SHALLOW DEPTH; ANTICYCLONES; LOW HUMIDITY; FORECASTING; LAYERS; FOG DISPERSAL; AEROSOLS; PREDICTIONS; AESOP EXPERT SYSTEM; TAYLOR FOG; MIDLATITUDES; EXPERT SYSTEMS; PE62435N; WUDN656766; North Atlantic
• Online Access: http://www.dtic.mil/docs/citations/ADA211780; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA211780

Ocean fog and haze were studied to provide additional expertise for An Expert-system for Shipboard Obscuration Prediction (AESOP). Task I studied fog occurrence in the N. Atlantic and developed an AESOP rule base for these fogs, Task II evaluated forecast errors generated during a test of AESOP, and modified and extended the rule base to correct for these errors. Fog is primarily a summertime phenomenon in the N. Atlantic. Taylor fog forms at midlatitudes (40-50N) in the stable, relatively shallow marine boundary layer which is located at the western end of the semi-permanent anticyclone. In the eastern N. Atlantic extratropical anticyclogenesis occasionally occurs, which can produce stratus lowering fog along its eastern side and Taylor fog in the southerly flow at its western end. At 50-60N in the track of the transient synoptic systems, much of the fog is advected in from the Taylor fog formation regions to the S and W. Fog dissipation is driven primarily by heating produced by absorption of solar radiation and mixing of warm air from above the inversion which caps the fog layer. These two dissipation processes are abetted by the mixing of the lower humidity of the warm air. Over the open ocean, the aerosol concentration is generally too low to provide even the minimum concentration required to produce a maximum haze visibility of 5 n mi.