The Character of Sea Fog in the Urban Area of Kushiro City, Eastern Hokkaido

摘要

Surface Observation of sea fog was carried out in and around Kushiro City on the south-eastern coast of Hokkaido from July 14 to July 20, 1981 and from July 26 to August 4, 1982. The relation between water content and visibility at the observation points in the urban area and in the coastal suburbs was examined with the data gathered from the continuous measurement of water content and visibility. The followings were clarified by analysing the equation of the relation between water content and visibility. The first, the visibility in the urban area was higher than that in the coastal suburbs at a certain value of water content. And the second, the increaseing rate of visibility accompanied by a decrease in water content in the urban area was larger than that in the coastal suburbs. These characteristics are interpreated as follows: 1) Small droplets of sea fog are dissipated in the urban area and 2) Mean radius of the distribution of the size of the fog droplets varied with the water content in the coastal suburbs.