'Handbook of Mesopotamia. Vol. I. 1918' [‎37] (46/568)

CLIMATE
37
Cloud (Table XIII, p. 54)
9011 Cloudiness is naturally much less in the arid climate of southern
Mesopotamia than under the somewhat moister conditions of the
country to the north of Baghdad. Both that station and Babylon,
however, show a well-marked cloudy season from December to
April, while from June to September the sky is almost cloudless.
j A similar annual variation of cloudiness is noticeable at the northern
• : end of the Persian Gulf The historical term used to describe the body of water between the Arabian Peninsula and Iran. , while at places nearer to the Indian Ocean,
e'ifVi as Jask and Muscat, July and August are months of much
e( j | Before the war the winds of Mesopotamia had been observed at five
«» stations, viz. Urfeh, Mosul, Baghdad, Babylon, and Basra; but at
J Baghdad and Basra the observations were made at 8 a.m. only, while
at the other places three observations daily—at 8 a.m., 2 p.m., and
p, 7 p.m. or 8.30 p.m.—are available, and give a better representation
, s , t of the air movement.
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The mean wind directions for each month, expressed as per
centages of the total directions observed in the month, are given
in Table XI, p. 52, where it will be seen that the dominant wind
direction in all months is the north-west, inclining at one time
more to the west and at another to the north. In the summer
the north-west wind shows the greatest steadiness at all stations,
when it reaches a frequency percentage of 70 to 80. In winter and
Jn spring the southerly and easterly winds attain their greatest fre-
lOMii quency, but there is a recognizable difference at the different stations.
At Urfeh calms are not indicated in the observations, and in the
JiBi winter months easterly and southerly winds have each about half
mi® the frequency of the north-westerly. At this station southerly
flit winds are fairly frequent at all seasons, but, as elsewhere, are at the
minimum in the summer months.
At Mosul calms are few, and the north-westerly winds are still
predominant, reaching 77-7 per cent, in the summer months. At
that season southerly winds are comparatively rare, but they reach
# P er cenfc - i* 1 winter months, and as south-easterly winds con-
a tinue into April and May.
j At Baghdad the observations were made at 8 a.m. only, and a very
. ( || high percentage of calms was recorded—from 584 per cent, in
jjp December to 22-9 per cent, in July. This high proportion may be
due to local conditions, but also the light airs of the winter
6 mornings have probably been recorded as calms, since Dr. A.
Winds (Table XI, pp. 52-4)
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