38 METEOROLOGICAL RESULTS OF LAST CRUISE OF CARNEGIE 
indicated in figure 14, however, the sea-temperature 
data appear to present two maxima, one between lati- 
tudes 5° and 15° north, and another, less pronounced, 
between latitudes 5° and 15° south. Thus the effect of 
ocean currents on mean sea-surface temperatures im- 
mediately becomes evident. The minimum at the equa- 
tor is no doubt emphasized by the fact that many of the 
Carnegie sea-temperature data between latitudes +5° 
were collected in the vicinity of the Galapagos Islands 
where sea-surface temperatures are abnormally low 
because of the importation of cold southern waters by 
the Southern Equatorial Counter Current. 
An examination of figure 14 reveals the fact that the 
sea- and air-temperature curves follow each other very 
closely for all latitudes. 
Sea-Surface Temperatures in the North Atlantic Ocean 
Sea-surface isotherms for the North Atlantic, con- 
structed from the Carnegie hourly sea-temperature data, 
have been plotted in figure 28 for the purpose of illus- 
trating the horizontal distribution of sea-surface tem- 
peratures over this region. An examination of this fig- 
ure reveals that there are five general Zones within 
which the concentration of isotherms is at a maximum. 
The first (I) occurs south of Iceland, approximately in 
latitude 65° north, and between longitudes 10° and 24° 
west. This is a region where considerable mixing of 
northern and southern waters is taking place, and thus 
we would expect it to be also a region presenting a rath- 
er wide range of sea-surface temperature. 
The greatest concentration of isotherms in the North 
Atlantic (II) occurs off the east coast of Newfoundland 
and Nova Scotia in longitude 48° west, where the Carne- 
gie passed from the cold Labrador Current into the 
warmer waters of the Gulf Stream. During one part of 
this transition, the sea-surface temperature rose 7:5 in 
approximately one degree of latitude. 
Zones III and IV present some slight temperature 
irregularities, and were no doubt located on the bound- 
ary between the Gulf Stream and the Sargasso Sea. 
Zone V (latitude 14° north, longitude 38° west) ap- 
pears to be within the Atlantic Equatorial Current or 
along the boundary between this current and the inter- 
mittent Guinea Current. It may be of interest to point 
out that the highest sea-surface temperatures recorded 
by the Carnegie in the North Atlantic occurred in this 
region. 
It may also be noteworthy that there is remarkable 
uniformity of temperature in the Caribbean Sea. The 
sea-surface temperature remained between 28° and 29° 
during all that part of the cruise from latitude 13° north, 
longitude 54° west, to Colon, a distance of approximate- 
ly 1500 miles. 
Sea-Surface Temperatures in the North Pacific Ocean 
Sea-surface isotherms for the North Pacific Ocean 
have been plotted along the route followed by the Carne- 
gie and the results are presented in figure 29 and 30. 
Only two zones of marked temperature variation appear 
to exist: one (I) off the coast of California in the latitude 
of San Francisco, where the Carnegie crossed the Cali- 
fornia Current, and the other (II) off the northwest coast 
of Japan, where the course of the Carnegie appears to 
have paralleled the boundary between the cold Oyashio 
Current and the warmer Kuroshio Current. During the 
period when the Carnegie remained in port at Yokohama 
(June 7 to 24, 1929), sea-surface temperatures, in gen- 
eral, appear to have increased about 6°, indicating a 
significant change in water mass in this area during the 
three-week period. 
On June 30, 1929, in latitude 38° north, longitude 147° 
east, a sudden fall intemperature of 5°8 occurred between 
08h and 09h 30m, revealing a very sharp temperature 
discontinuity between the two currents at this point. 
Sea-surface temperatures throughout the southwest- 
ern North Pacific were extremely uniform; the extreme 
temperature variation for that part of the cruise from 
the equator at longitude 172° west to Guam amounted to 
only 1°. 
Sea-Surface Temperatures in the South Pacific Ocean 
Sea-surface isotherms for the South Pacific Ocean, 
as determined from the Carnegie data, are shown infig- 
ure 29 and 30. Here, again, there appear to be only two 
Zones presenting marked temperature gradients. The 
first (I) occurs to the south of the Galapagos Islands 
within the comparatively cold waters of the Southern 
Equatorial Current, a region of marked divergence, and 
the other (II) occurs off the coast of Peru in the latitude 
of Callao, where the Carnegie crossed the cold Coastal 
Peru Current, which flows very close to the coast inthis 
region. The temperature gradient across the Coastal 
Peru Current, was not as steep as has been indicated by 
previous investigations made during summer months in 
this region. 
Sea-surface temperatures throughout most of the 
remainder of the cruise in the South Pacific were very 
uniform, although there appear to be slight concentra- 
tions of isotherms in the area around Easter Island and 
again in latitude 36° south, longitude 105° west. These 
latter Zones are too far north to be under the influence 
of the zone of subtropical convergence; thus these tem- 
perature irregularities must be due to some displace- 
ment of the usual South Pacific drift. 
CONCLUSION 
In concluding this section on sea-surface tempera- 
tures, it may again be emphasized that since differences 
between sea and air temperatures are usually less than 
1°, for purposes of studying the effects of sea-surface 
temperature on the physical processes of the atmos- 
phere it becomes necessary to obtain air temperatures 
accurate to the nearest 0°1. For this purpose, methods 
must be devised for obtaining these continuous air tem- 
peratures free from the local effects of heating and cool- 
ing. It has been shown that it is possible to ascertain 
sea-surface temperatures with considerable accuracy. 
The Carnegie data indicate that if air temperatures 
could be obtained a few meters above the sea surface, 
free from the effects of insolation, radiation, and arti- 
ficial heating, it would be found that even the mean hour- 
ly air temperatures would seldom be above the mean 
hourly sea temperatures. Certainly the sea exerts a 
tremendous thermal influence on the atmosphere. 
