Sea Temperatures — LEIPPER and ANDERSON 
Two groups of cruises, designated as the 
H and Q cruises, were made near the entrance 
to Pearl Harbor during 1944 and the early 
part of 1945. The following tabulation shows 
the dates of these cruises as well as the num- 
ber of bathythermograph observations taken. 
H and Q Cruise Data 
CRUISE 
DATE 
NUMBER OF 
BATHY- 
THERMOGRAMS 
Q-l 
2/24/44- 3/29/44 
60 
Q-2 
3/29/44- 4/22/44 
60 
Q-3 
4/23/44- 5/14/44 
60 
Q-4 
5/15/44- 6/26/44 
60 
Q-5 
6/27/44- 9/ 4/44 
60 
Q-6 
9/15/44-11/13/44 
60 
Q-7 
11/14/44- 2/12/45 
60 
Q-8 
2/12/45- 2/20/45 
7 
H-l 
3/13/44- 3/29/44 
42 
H-2 
3 / 29 / 44 - 4/17/44 
56 
H-3 
4 / 17 / 44 - 5/ 6/44 
57 
H-4 
5/ 6/44- 5/30/44 
60 
H-5 
6/ 1/44-10/ 9/44 
108 
H-6 
11/16/44- 2/20/45 
63 
HORIZONTAL TEMPERATURE DISTRIBUTION 
Horizontal temperature distribution based on 
averages by 1 -degree quadrangles of latitude 
and longitude 
The horizontal distribution of average tem- 
perature at the surface and at depths of 100 
feet, 200 feet, and 300 feet is shown in 
Figures 2 to 13 for each of the 12 months 
of the year. March and September average 
temperatures were, respectively, lowest and 
highest of the year. June and December were 
months having temperature distributions typ- 
ical of months of transition. 
In preparing the monthly average temper- 
ature charts, the following procedure was 
used: At each depth level, all available tem- 
peratures for each 1 -degree quadrangle were 
averaged by months. To obtain time conti- 
nuity, the monthly averages for each quad- 
rangle where there were sufficient data were 
plotted against time, and a curve, smoothed 
visually, was drawn through the points. 
Monthly average temperatures were then read 
229 
from this smoothed curve. The values for 
each month were plotted on a map by posi- 
tion, and the isotherms were drawn. 
The ocean current systems which are pres- 
ent affect the horizontal temperature distri- 
bution. In March the southern portion of the 
Hawaiian Island area is under the influence 
of the northeast trade winds with a resulting 
ocean current toward the west known as the 
North Equatorial Current. In the northerly 
portion of the area the North Pacific Current 
flows toward the southeast. Between these 
two currents as shown in Figure 14 is a region 
where the flow is variable (Sverdrup, John- 
son, and Fleming, 1946: 723, appendix, 
Chart VII). This region coincides with the 
region where the pattern of isotherms is most 
irregular, as shown in Figures 2 to 13. 
The extremes of average temperature 
For each month of the year, at particular 
depths, the maximum average monthly tem- 
perature occurring in any 1 -degree quad- 
rangle of the Hawaiian Island area was se- 
lected. Similarly, the minimum average was 
obtained. These, together with the differences 
between them, are presented in Table 4 at 
several depths for each month. At the sur- 
face and at 100 feet, the differences are 
smaller during the summer than during the 
winter. At 200 and 300 feet, the differences 
appear to be almost constant. 
Table 5 (page 233) shows results of anal- 
ysis of the smoothed annual temperature- 
variation curves which were drawn for each 
1 -degree quadrangle as explained earlier. An 
examination of the table shows that the min- 
imum occurred the greatest percentage of the 
time in March at all levels except 300 feet; 
and the maximum, in September at all levels 
except 300 feet. At 300 feet the minimum 
occurred most often in April and the max- 
imum most often in October. 
Figures 16 and 17 present the maximum 
and minimum monthly average temperatures, 
respectively, for the surface and the 100-, 
