The Geographical Journal (Journal of the Royal Geographical Society): Volume XII, No. 2 [‎266v] (35/154)

126 THE ANNUAL RANGE OF TEMPERATURE IN THE SURFACE WATERS OF THE
A range of surface temperature exceeding 40° Fahr. occurs in the
north-western portions of the Atlantic and Pacific oceans, in which
positions the greatest range in the surface waters of the globe is found.
The observations within the North Atlantic area show a range from 26°
to 83°, and within the North Pacific area from 28 , 8° to 88°. There are
indications that in the eastern part of the Mediterranean, near the island
of Cyprus, the surface waters have also a range exceeding 40°, while
in the north-western part of the Black sea a similar large range occurs.
A range exceeding 45° Fahr. occurs only in the North-West Atlantic
and North-West Pacific, each enclosing an area having a range of more
than 50° Fahr.
A range of surface temperature exceeding 50° Fahr. is found only
in the North-West Atlantic and North-West Pacific. The North Atlantic
area is much the larger, extending ofi' the North American coast, to the
south of Nova Scotia, seaward to near long. 50° W. The greatest
recorded range in a single square is 52° (from 28° to 80°), while the
extreme range within the area is from 27° to 83°. The North Pacific
area lies off the coast of Asia in the Sea of Japan, in about the same
latitude as the Atlantic area (40“ N.). The greatest recorded range in
a single square is 52-7° (from 28-8 0 to 81-o°), and the extreme range
within the area is from 28'8 0 to SS 1 ?' Fahr.
From the foregoing discussion it will be seen that the lowest recorded
temperature-reading at the surface of the sea is 26° Fahr. in the North
Atlantic, eastward of Nova Scotia, and the highest reading in the open
ocean is 90° Fahr., recorded in the tropical Pacific both north and south
of the equator, though readings of 94° and 96° Fahr. are recorded in the
Red sea and Persian gulf The historical term used to describe the body of water between the Arabian Peninsula and Iran. respectively. The greatest known range of
temperature of the surface waters throughout the whole world is thus
70° Fahr. (from 26° to 96°).*
4. Relation of Range of Temperature to some other Physical
Phenomena.
Range of temperature has a very important effect in bringing about
a vertical circulation in ocean waters. In the equatorial regions, where
there is hardly any variation of surface temperature, the warm water
remains at the surface, and there relatively cold water comes nearer to
the surface than in those regions in temperate zones where there is a
wider daily and annual range. The cooling of the surface layers at
night and during winter in temperate regions causes the salter waters of
the surface to sink through the underlying layers, carrying with them
heat and atmospheric gases to the greater depths. The effect of freezing
I he colours indicated on the map for the bodies of fresh water (such as the North
American and Siberian lakes) have been laid down from a study of all accessible
information.