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The Atlas of Caspian Sea Hydromorphology
effects in summer. The position of Caspian Sea in various climatic
regions resulted in dissimilar temperature distribution in the air above
the Caspian Sea. The annual mean of air temperature varies from 10
degrees centigrade in northern part to 17 degrees centigrade in
southern part of Caspian Sea. The coldest month in the Caspian Sea is
January and the hottest months are July and August.
In Caspian Sea, the most important factors determining wind speed
and direction are: the atmospheric general cycle parameter, the
sea-resulted temperature field, and the coast roughness. The dominant
winds regimes in the Caspian Sea include north winds (northeast,
north, northwest) and the southeast winds which are dominant in
most times of the year. The mean of wind speed in the Caspian Sea
water area is 5/7 meters per second. The maximal wind speed is
observed in the middle part of Caspian Sea, and its annual mean is
6-7 meters per second. In the Absheron region, the wind speed is
8-9 meters per second. In this region, the northwestward dominant
winds have the speed of more than 25-30 meters per second and are
considered as the north winds.
The precipitation distribution over the Caspian Sea water area is too
unbalanced and its rate in the western coast of southern part varies
from 110 millimeters per year in Neftianie Kamni to 1250 millimeters
per year in Lankaran zone. The eastern coast of Caspian Sea is
considered as a dry region and the maximal precipitation in this
region doesn’t exceed 15-200 millimeters per year. In Iran’s coast,
which has a humid climate, the precipitation rate varies from 1000 to
2000 millimeters per year. Glacial occurrence in November is one of
