Page 55 - (DK) Ocean - The Definitive Visual Guide

OCEAN WATER IS constantly in motion, and
not simply in the form of waves. Throughout

the oceans, there is a continuous circulation

of seawater, both across the surface and
more slowly deeper down. Several related

processes play a part in causing and

maintaining these ocean currents. They

include solar heating of the atmosphere,

prevailing winds, the effect of Earth’s
rotation, and processes that affect the

temperature and salinity of surface waters.

The various surface currents that are
generated, some warm, some cold, have

profound effects on climate in many parts

of the world. Oceanic processes also play

a part in the periodic climatic disturbances

called El Niño and La Niña, and they help
generate the extreme weather phenomena

known as hurricanes and typhoons.

CIRCULATION AND CLIMATE

SPIRALING STORMS
Two cyclones—spiraling areas of low
atmospheric pressure accompanied by
cloud—are visible in this satellite image
of part of the North Atlantic, taken in late
2006. The cyclones are moving eastward
to the south of Iceland, which can be seen
at top center.