SEA-SURFACE TEMPERATURE 
37 
Tabie 43. Diurnal variation oi weighted means and differences between temperatures oi sea (corrected 
for noncyclic change) and air (corrected for noncyclic change and for radiation) 
in groups I to XI, Carnegie, 1928-29 

Local mean hours 
Group 
°c ae 2G SC ac 
I 9 +0.66 +0.75 +0.87 +0.91 +0.85 
0 4 +1.88 +2.06 +1.98 +1.84 +1.65 
ii 13 +0.49 +0.47 +0.45 +0.46 +0.38 
IV 21 +0.86 +0.93 +0.96 +0.86 +0.92 
v 9 +0.43 +0.47 +0.54 +0.69 +0.68 
VI- 12 41.35 +1.47 +1.51 +1.39 +1.42 
vil 
(3) 35 +0.77 +0.83 +0.81 +0.81 +0.89 
b 8 +0.32 +0.39 +0.35 +0.29 +0.31 
Vill 14 +0.03 +0.33 +0.30 +0.29 +0.35 
13:4 12 +0.29 +0.49 +0.45 +0.48 +0.49 
x 7 +0.41 +0.48 +0.62 +0.61 +0.57 
XI 21 +0.65 +0.97 +0.89 +0.91 +0.89 
Total GSP race e fs eae eb oceacco” Saban 
Weighted 
means ..... +0.67 +0.78 +0.78 +0.78 +0.78 
cays ess Sates SRE Ds ES a Be es 
xe 
+0.13 
+0.65 
+0.18 
-0.05 
+0.45 
+1.74 
KG 
+0.40 
+0.83 
+0.13 
-0.23 
+0.10 
+1.72 
°E 
+0.59 
+1.55 
+0.17 
+0.i1 
-0.02 
+ 1.64 
+0.25 
+0.00. 
ic 
+0.69 
+1.68 
+0.45 
+0.54 
+0.18 
+1.61 
ie 
+0.88 
+1.53 
+0.45 
+0.74 
+0.43 
+1.57 
+0.73. 
1G 
+0.80 
+1.39 
+0.38 
+0.86 
+0.68 
+1.45 
+0.88 
+0. 25 
+0.48 +0.06 
+0.25 
+0.77 +0.70 +0.51 
+0.26 +0.10 +0.13 +0.21 

Local mean hours 
Group 
ee 2 || Ste ys es 
2c 
+0.35 
+1.48 
+0.01 
+0.57 
+0.48 
+1.22 
2G 
+0.24 
+1.94 
-0.03 
+0.46 
+ 0.06 
+1.14 
+0.40 
-0.08 
-0.73 
+0.04 +0.04 
+0.11_, -0.01 
+0.70 +0.51 
+0.32 +0.33 
°C 
+0.30 
+1.91 
+0.04 
+0.25 
-0.01 
+1.34 
°C 
+0.32 
+1.40 
+0.13 
+0.23 
+0.00 
+1.43 
+0.28 
+0.28 
-0.59 
+0.07 
-0.04 
+0.40 
+0.26 
aC aC 
+0.25 +0.42 
+0.43 +1.15 
+0.16 +0.12 
+0.28 +0.19 
+0.23 +0.16 
+1.60 +1.44 
+0.28 +0.31 
+0.09 -0.03 
-0.20 -0.26 
+0.01 +0.24 
-0.04 -0.02 
+6.03 +0.24 
+0.25 +0.29 
+0.47 
-0.10 
-0.91 
+0.40 
+0.08 
-0.60 
-0.07 
+0.03 
+0.60 
+0.30 
—w- 
Mw iood <BR. 
Weighted 
means 
Mean 
a 
1G °C xG 5c cc 
+0.70 +0.54 +0.56 +0.76 +0.55 
+2.30 +2.38 +2.29 +1.88 +1.62 
+0.21 +0.40 +0.33 +0.48 +0.26 
+0.71 +0.72 +0.72 +0.79 +0.54 
+0.64 +0.60 +0.60 +0.42 +0.39 
Pee Gl eae by eerlec hh aegis ty Saldl 
+0.59 +0.61 +0.53 
+0.22 +0.28 +0.17 
+0.08 +0.14 -0.13 
+0.33 +0.37 +0.22 
+0.18 +0.28 +0.22 
+0.72 +0.82 +0.54 
+0.60 +0.63 +0.49 
4G 
+0.45 
+1.60 
+0.04 
+0.70 
+0.60 
+1.34 
+0.63 
+0.06 
-0.60 
+0.08 
+0.04 
+0.54 
+0.45 
°c 
+0.66 
+2.18 
+0.16 
+0.71 
+0.64 
+1.40 
+0.63 
+0.05 
-0.37 
+0.31 
+0.18 
+0.75 
+0.56 
+0.66 
+0.17 
+0.06 
+0.32 
+0.26 
+0.68 
+0.61 
+0.64 
+0.26 
+0.20 
+0.35 
+0.30 
+0.84 
+0.66 

the Groups in which the air temperature was greater 
than the sea temperature in the morning, and then fell 
below for the rest of the day, the air temperature was at 
a maximum about i0h. The most plausibie explanation 
for this seems to be found in the records of cloudiness 
from the log abstract and from records during atmos- 
pheric-eleciric observations, which indicate that days 
included in means which had an early maximum were 
also days when the sky became cloudy during the late 
morning and remained cloudy the rest of the day, thus 
producing an effect comparable with that of a mountain 
climate in summer. 
Regionai Variations 
in Sea-Surface Temperatures 
General Remarks 
Sea-surface temperatures over the greater part of 
the ocean, in general, are remarkably uniform from day 
to day, and rapid spatiai temperature changes appear to 
occur only along the boundaries of well-developed ocean 
currents where displacements of large water masses 
are taking place. Thus we may assume that any zone 
which presents a complicated pattern of isotherms 
bounds a region within which significant water transport 
is occurring. It was hoped that by plotting isothermal 
maps, using the Carnegie sea-surface temperature data, 
it would be possible to show those general regions where 
such transport was taking place, and, by observing the 
regions where the concentration of isotherms was at a 
maximum, accurately to define the boundaries of the 
more important ocean currents. Unfortunately, the 
original logbook of the Carnegie was lost, and it is im- 
possible definitely to place rapid temperature changes 
shown by the data, with respect either to geographical 
position or the horizontal distance over which the given 
change took place (dt/ds). It is believed, however, that 
the data will show those general regions wherein tem- 
perature gradients are steep, although the exact slope 
and location in each case must remain in doubt. 
Variation of Sea-Surface Temperature with Latitude 
If the sea were a more or less stationary fluid body, 
we should expect the mean sea-surface temperatures 
averaged throughout the year to be at a maximum near 
the equator and to fall off gradualiy toward the poles. As 
