208 
PACIFIC SCIENCE, VoL IX, April, 1955 
z = 3D Z . Still, we should be able to expect some important conclusions from what has 
been completed thus far. 
First of all it is very interesting that the wind-driven currents exist in a layer much 
deeper than that expected from the classical theory of Ekman (1905). According to Ek- 
man’s theory, a wind-driven current is confined to the surface layer about D z thick, and 
we can expect practically no drift current at a deeper level than 150 m. except very close 
to the equator. From our computation, it can be shown that the current velocity does not 
drop as low as half the surface value even at a level 3D Z . If we take D z = 75 meters, this 
depth is 225 meters. 
This conclusion will help us understand the fact that wind-driven currents can pene- 
trate into a layer several hundred meters deep, several times as deep as that expected 
TABLE 5 
Four Roots of the Equation: <r 4 - 1082323+<r 2 - 149971 10o- + 11514116?7 2 = 0 O = 1) 
For Different Values of r \. Refer to Equation (73) 
V 
a 
|3 
7 
8 
0.1 
261.21657 | 
i - 130.612124 
1 - 200.8814951 
0.0076775 < 
l -130.612124 
1 +200.8814951 
0.2 
304.26551 \ 
1 - 152.148109 
1 - 161.6954191 
0.0307072 < 
1 -152.148109 
> +161.6954191 
0.3 
371.21622 J 
1 — 185.642643 
I - 77.1685151 
0.0690668 < 
i; 
185.642643 
77.1685151 
0.4 
454.08159 
- 363.12143 
0.122667 
— 
91.082828 
0.5 
545.93222 
- 489.85023 
0.191279 
— 
56.273270 
0.6 
642.62244 
- 603.98223 
0.27443 6 
— 
38.914645 
0.7 
741.9839 6 
- 713.66160 
0.371324 
— 
28.693687 
0.8 
842.89309 
- 821.22710 
0.480691 
— 
22.146678 
0.9 
944.74621 
- 927.63340 
0.600783 
— 
17.713594 
1.0 
1047.20274 
- 1033.34356 
0.72937 
— 
14.58855 
1.1 
1150.06112 
- 1138.60821 
0.86382 
— 
12.31673 
1.2 
1253.19657 
- 1243.5733 6 
1.00136 
— 
10.62457 
t.3 
1356.52895 
- 1348.32950 
1.13922 
- 
9.33867 
1.4 
1460.00495 
- 1452.93512 
1.27490 
— 
8.34473 
1.5 
1563.5883 
- 1557.4297 
1.40631 
— 
7.56490 
1.6 
1667.2526 
- 1661.8399 
1.53190 
— 
6.94465 
1.7 
1770.9803 
- 1766.1856 
1.65059 
— 
6.44526 
1.8 
1874.7576 
- 1870.4809 
1.76177 
— 
6.03849 
1.9 
1978.5740 
- 1974.7356 
1.86521 
— 
5.70361 
2.0 
2082.4224 
- 2078.9583 
1.96096 
— 
5.42509 
2.5 
2601.9746 
- 2599.7576 
2.33637 
— 
4.55339 
3.0 
3121.8104 
- 3120.2708 
2.58146 
— 
4.12107 
3.5 
3641.7804 
- 3640.6492 
2.74475 
— 
3.87598 
4.0 
4161.8219 
- 4160.9559 
2.85725 
— 
3.72328 
4.5 
4681.9050 
- 4681.2207 
2.93742 
— 
3.62168 
5.0 
5202.0138 
- 5201.4595 
2.99627 
— 
3.55053 
5.5 
5722.139 6 
- 5721.6815 
3.04065 
— 
3.49871 
6.0 
6242.2768 
- 6241.8919 
3.07487 
— 
3.45977 
6.5 
6762.4223 
- 6762.0943 
3.10178 
— 
3.42975 
7.0 
7282.5734 
- 7282.2906 
3.12332 
— 
3.40610 
7.5 
7802.7290 
- 7802.4827 
3.14080 
IS! 
3.38714 
8.0 
8322.8879 
- 8322.6714 
3.15518 
— 
3.37170 
8.5 
8843.0494 
- 8842.8577 
3.16716 
— 
3.35890 
9-0 
9363.2128 
- 9363.0417 
3.17724 
— 
3.34830 
9.5 
9883.3778 
- 9883.2242 
3.18579 
3.33937 
10.0 
10403.544 
-10403.405 
3.19310 
— 
3.33166 
