The Near Eastern climate is a function of the region's
position
sandwiched between two major landmasses, Africa and northern Eurasia.
On the African side the Near East is subject to hot air from the
Sahara, of which the Arabian desert is in effect an eastward extension.
On the Eurasian side the climate is strongly influenced by cold air
from Siberia. Since these air flows are amongst the world's most
effective heating and cooling systems, they do much to explain the
extremes of temperature to which the Near East is subject. But there is
one thing that continental airmasses, whether hot or cold, tend to have
in common: they are dry.
This means that if the Near East is receive rainfall,
it has to come
from the adjoining seas. Owing to the direction of the prevailing
winds, the Near East derives very little benefit from the proximity of
the Indian Ocean. This is why Arabia is a desert and not a tropical
jungle. The Near East is thus left with the Mediterranean, a far less
generous source of rainfall, and even then only in winter. The main
factors enabling a region to draw on this source are its mountains. The
effect of these is to establish a marked aridity gradient across the
Near East. Overall it is wettest in the northwest, and driest in the
southeast. Thus only about 3 percent of the surface area of Turkey is
desert, whereas for Saudi Arabia the figure is more like 97 percent.
