Table 1. Hydrometeorological observations.
Variable
Mean
StdD
Min
Max
N*
February 1990
Dry bulb (C)
10.2
2.3
14.0
5.0
40
Wet bulb (C)
10.9
2.2
15.1
6.2
38
Rel. wind vel. (m s1)
12.3
6.5
2.1
24.2
40
Rel. wind dir. ()
174.9
79.5
21.2
353.8
40
Wind direction ()
90.3
107.4
1.0
350.0
40
Wind speed (m s1)
11.1
6.2
1.5
20.1
40
Rel. wave dir. ()
169.9
118.4
3.0
359.0
15
Rel. swell dir. ()
118.7
93.1
9.0
279.0
16
Course ()
127.2
89.9
1.0
321.0
40
Ship speed (m s1)
3.0
2.7
0.3
8.7
40
Air pressure (kPa)
101.5
0.1
99.4
102.0
40
Wave direction ()
57.3
86.6
0.0
224.0
15
Wave height (m)
1.0
0.5
0.3
1.8
15
Swell direction ()
41.9
83.2
0.0
350.0
16
Swell height (m)
1.6
0.7
0.6
2.4
16
Water temperature (C)
1.8
--
0.2
3.4
15
Water salinity (‰)
33.1
--
33.0
33.5
15
Beaufort wind force
5.9
2.1
2.0
9.0
36
Wave + swell ht. (m)
3.1
1.0
1.8
4.3
12
Wave-swell angle ()
40.2
97.7
6.0
350.0
12
March 1990
Dry bulb (C)
5.6
3.7
12.9
0.6
162
Wet bulb (C)
6.0
3.7
12.9
0.6
162
Rel. wind vel. (m s1)
10.4
2.5
4.2
19.0
170
Rel. wind dir. ()
155.6
81.8
51.6
342.3
170
Wind direction ()
170.8
139.9
4.0
355.0
170
Wind speed (m s1)
11.3
3.3
4.1
18.0
170
Rel. wave dir. ()
201.3
108.6
19.0
349.0
69
Rel. swell dir. ()
183.2
103.2
9.0
349.0
94
Course ()
168.9
93.1
1.0
355.0
170
Ship speed (m s1)
6.2
2.5
0.3
8.2
170
Air pressure (kPa)
100.5
0.8
99.4
102.3
170
Wave direction ()
117.3
123.6
10.0
350.0
69
Wave height (m)
0.9
0.2
0.6
1.2
69
Swell direction ()
48.3
63.1
0.0
335.0
94
Swell height (m)
1.4
0.3
0.9
2.1
94
Water temperature (C)
2.2
--
1.1
3.2
12
Water salinity (‰)
34.1
--
33.9
34.4
12
Beaufort wind force
5.2
1.0
3.0
8.0
141
Wave + swell ht. (m)
2.4
0.6
1.5
3.4
69
Wave-swell angle ()
66.2
116.1
0.0
330.0
69
*Number of samples.
a direction of 90, head winds a direction of 180, and
ship heading and seaway conditions interact so strongly
starboard beam winds 270.
with ship speed to produce spray.
Relative wind speeds across the bow were computed
Relative wind velocities were somewhat larger in
the February event, with a maximum of 24.2 m s1
from true wind speed, ship speed, and true wind direc-
(Table 1). Relative wind directions averaged about 175
tion (Ryerson and Longo 1992). Relative wind direc-
tion was computed at the same time, but direction is
in the February event, almost on the bow, but were about
156 in March, 24 to port. Kultashev et al. (1972) found
computed clockwise from the stern, instead of from the
bow, to minimize mathematical errors arising from
spraying to be greatest on trawlers when winds and seas
approached the ship 3040 off the bow. Japanese
averaging wind directions. Thus, port beam winds have
9
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