The southern coastal areas of the Caspian Sea play important role for using marine resources
of the sea. According to the importance of the monitoring and gathering good data about the
above mentioned area, study on physical parameters and characteristic was considered.
Variations of physical parameters in the southern coastal waters of the Caspian Sea was studied
based on the field measurements. In addition, forming and destructure of thermocline and
picnocline, and stability of water column were evaluated. Field investigations were carried out
by CTD profiling in the cosatal waters of Nowshahr port and Anzali and Torkmen areas.
Measurements were conducted on fixed sampling stations. Data collections in March, April,
May, June, August, September, October 2014 January and February 2015 were performed.
Results showed that the sea surface water tempertaure ranged between 9 and 30oC,
aproximately in the southern coastal waters during the year. Stratification in the water column
in the southern coastal waters of the Caspian Sea starts early spring with gradual warming of
the air in the region, and then it reached to the strongest situation in the middle month of
summer. Destruction of thermal stratification in water column was occurred during late
autumn to winter. The most variations of physical properties of seawater were occurred
across the upper 100 m layer. A seasonal thermocline was detected with 30 m thikness
between 20 and 50 m depths in summer. Vertical density variation, considering small vertical
salinity variations, was highly correlated with vertical temperature variations. The vertical
variations of water density was agreed with the variations of temperature in water column,
and a strong pycnocline layer was observed at the location of the thermocline layer.
Measeured water salinity in the coastal waters of Torkmen port in February was more than
that in may.