An Observation of the Modification of a Mesoscale Cold Airmass over a Warm Sea Surface, Utilizing the Height and Temperature of Steam Fog Top

[摘要] As a preliminary observation of AMTEX, GARP, the modification of a mesoscale cold airmass over Ishikari Bay was measured in January 1972.A wide-spread steam fog was produced over the sea surface with a temperature of +2.5°C by the outflow of cold air with a temperature of -11.5°C and a humidity of 60 %. The thermal diffusion coefficient of the air was estimated as 0.7 m2•sec-1 in the range between the surface and the 9 m height above sea level near the seashore under the wind speed condition of 3 m•sec-1, by measuring the height of the fog top, besides the vertical structure of the outflowing cold air.Based on this value of diffusion coefficient, the heat flux was estimated as 1, 500 ly•day-1.

[学科分类] 大气科学