周根泉

A Research of Vertical Variations of Micrometeorological Factors During Fog Formation

Ken-Chuan Chou

Abstract

　　An observational study of meteorological conditions associated with the fog occurrence is made for the station at Depatment of Atmospheric Science, National Taiwan University・ Automatic recording data of temperature, dew point and wind, obtained at various levels on towers as well as the surface weather maps in the year of 1976—1977 are analyzed. Results and summarized as follows:

1. Radiation fog frequently observed under light wind after sunset w让h large decrement of air temperature and increment of humidity near ground surface.

2. Both temperature and humidity are almost steady during occurrence of radiation fog. Radiation fog tends to dissipate temporary during the period of gusty wind occasionally as temperature increases and humidity decreases slightly at the same time.

3. Frontal fog is observed without a temperature inversion near the ground,and the difference of temperature and humidity with time are small.

4. The “raised minimum temperature” is usually found at near 20cm to 40cm above the ground at the formation stage of a near ground inversion layer.

5. Frontal fog is observed occasionally during the cold front passage

And radiation fog after front passage during the winter season in Taipei area.

6. The wind associated with the frontal fog is generally stronger than that of the radiation fog.