Seasonal Variations — TsEU 
287 
ever, during the winter months from Decem- 
ber, 1949^ to January, 1950, and from Decem- 
ber, 1950, to January, 1951, the periods of 
”kona” weather and heavy rainfall (Fig. 10), 
a reverse situation was noted, and surface 
waters of lower temperatures were observed 
(Fig. 11). This was caused by the colder rain 
water floating on top of the warmer, more 
saline, and therefore more dense, bay water. 
In the three 24-hour periods of observation, 
a definite diurnal change in temperature was 
found with a minimum temperature in the 
morning hours from 0500 to 0800 and a max- 
imum temperature in the afternoon hours 
from 1200 to 1400 (Fig. 12). An increase of 
temperature range was noted from the De- 
cember to the August series. 
CHEMICAL CONDITIONS 
Water samples for determining tempera- 
ture, chlorinity, and oxygen content were col- 
lected simultaneously by means of the modi- 
fied oxygen sampler. Water temperatures were 
recorded immediately, chlorinity samples were 
transferred from the reservoir bottle into ci- 
Fig. 11. Comparison of water temperatures for a 
year at stations 1, 5, and lo. Temperature of surface 
waters shown by broken line, of bottom waters by 
solid line. 
trate of magnesia bottles for storage, and 
oxygen samples were preserved immediately 
in the BOD bottles in which they were col- 
lected. 
Chlorinity samples were analyzed by the 
Mohr technique (Thompson et aL, 1950: see 
section, ”The Determination of the Chlorin- 
.ity of Sea Water”; Kolthoff and Sandell, 1943: 
568-570). 
All chlorinity values were graphed to show 
seasonal variations and to compare some of 
the stations (Fig. 13). Averages were used 
when the differential between top and bottom 
was less than 0.25 parts per thousand. Chlorin- 
ities ranged from 14,94 parts per thousand 
to 19.88 parts per thousand. Throughout a 
greater part of the year, chlorinities did not 
show much variation until the great drop in 
chlorinity found in the winter months of Janu- 
ary, 1950, and December, 1950, and associ- 
ated with the onset of heavy rainstorms (Fig. 
10). To show the influence of rainfall on 
salinity, data were gathered routinely and 
compared with the chlorinity values of rep- 
resentative station 2 (Fig. 10). 
TIME 
Fig, 12. Comparison of water temperatures for three 
diurnal observations. Temperature of surface waters 
shown by broken line, of bottom waters by solid line. 
