103
The extent of coast over which fog prevaile at the same time is given in the following table:-
Table III.
Mean Percentage of Days in each Month when Fog prevailed on the same Day over various Sections of the China Coast during the five Years 1901-1905, inclusive.
Month.
South Coast and For- nosa Channel.
South Coast, Formosa Channel and Yangtze Estuary.
South Coast, Formosa Chan nel, Yangtze Estuary and Shantung.
Formosa
Formosa
Channel and
Channel,
Yangtze
Yangtze
Estuary.
Estuary and Shautung.
Yangtze Estuary and Shantung
January,
February, March,
73
3
0
11
4
1
0
2
3
14
10
3
15
8
11
April,
17
13
41
13
15
May,
1
1
28
12
21
June,
1
1
9
6
19
July. August, September, October, November,
December,
0
0
POON
0
0
1
1
0
The figures do not always quite agree with those given in Table II because the stations are in some instances too far asunder to show the lines of demarcation on the different sections of the coast, and also because it frequently happens that a station here and there records no fog while others in the same district all record fog. Thus in dealing with the areas over which fog existed on the same day it has been assumed that if the greater part of the stations in a given area recorded fog, or that the record was fairly well distributed over the area the condition of that area was foggy.
It will be noticed that the percentage of days when fog prevailed along the whole of the China coast on the same day is a small one, the maximum, occurring in April, being only four per cent. Between June and the following February no cases occurred. figures naturally increase as the extent of coast diminishes.
The
Fogs covering the most extensive areas of the coast on the same day were most frequent in April, except over the area from the Yangtze to Shantung and the Gulf of Pechili when May shows the greatest percentage. April is seen to be a very bad mouth along the stretch of coast comprised by the Formosa Channel and mouth of the Yangtze, the prevalence of fog on the same day being very frequent over the whole are. After April it seldom happens that fog embraces the S. coast and Formosa Channel areas at the same time, but they continue till about the middle of June in the area comprise 1 by the Formosa Channel and the Yangtze districts, and they disappear still later in the section of the coast comprised by the estuary of the Yangtze and the Shantung districts. After the end of July there are practically no fogs covering extensive sections of the coast on the same day. It is in January that they begin to increase again.