East Asia and Western Pacific METEOROLOGY AND CLIMATE

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showed a marked contrast between the earlier and later stages of the
Mei-Yu period.
Chen and Chi (29) analyzed 25 cases of fyfei-Yu frontogenesis in
1968 - 1977 and found that Mei-Yu fronts that affected Taiwan tended
to form in the region of 20~35°N and 100-130°E(Fig. 3). The life
time of these fronts ranged from 3 days to 22 days with an average
value of 8 days. Chi and Chen (48) used the same data set to analyze
the spatial distribution of the surface fronts. The maximum frequency
appeared to extend from the western Pacific to the Bashi Channel and
the South China Sea. A secondary maximum extended southwestward from
the East China Sea to northern Taiwan and southern China. For the 850
mb front, the maximun frequency extended fran the East China Sea to
northern Taiwan and southern China and a secondary maximim was
observed over the Bashi Channel and the South China Sea. The speed of
movement of the fronts at both the surface and 850 mb levels tended to
decrease as the Mei-Yu progresses.
IOO°E I!0°E 120°E I30°E
-J40°N
20°N h
IIO°E
I20°E
Fig.3 Frequency distribution of the surface frontogenesis during
Taiwan Nfei-Yu season (May 15 - June 15) of 1968-1977. The heavy
solid line indicates the boundary of polar front and Mei-Yu
front formations (29).