The mean frequency of sea fog occurrence in the west
sea is higher than that in the east sea throughout the
year and twice (5.3 days) the mean frequency in July
than the east sea (2.5 days). The standard deviations of
frequency are mostly as large as the mean frequencies
because of large year to year variation. However, the
order of sea in frequency is unchanged most years, as
the frequency fluctuates simultaneously at all seas. Considering
that both seas are located at the same latitude,
this difference may result from different sea surface