Masoud Torabi Azad; Abbas Ali Aliakbari Bidokhti; Hossein Salehianfar
Abstract
Many hydrological conditions in the seas depend on temperature variation, and the rate of this parameter is an important determinant in the environmental conditions of each area. The variations in temperature and surface wind causes changes in the density of the sea water, and the change in density affects ...
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Many hydrological conditions in the seas depend on temperature variation, and the rate of this parameter is an important determinant in the environmental conditions of each area. The variations in temperature and surface wind causes changes in the density of the sea water, and the change in density affects the stability rate and mixing of the sea water column. In this research, the mutual effect of sea surface temperature (SST) on surface wind speed in the southern Caspian region (Mazandaran province) has been investigated. First, the sea surface temperature data was collected by the AVHRR sensor of NOAA satellite and surface wind speed data was collected by QuikSCAT satellite for an area of 340 × 220 square kilometers in the southern Caspian Sea. After analyzing the satellite data for sea surface temperaturel, its monthly and seasonal variations were drawn by Tecplot software for this area. It was found that the average seasonal temperature (spring and summer) of the eastern coast of southern Caspian Sea is 0.87 degrees centigrade more than that of the eastern coast. In order to investigate the mutual effect of the sea surface temperature on surface wind speed, four stations, A and D (in the western region), B and C (in the eastern region) were selected on the southern Caspian Sea. Then, the graph of temperature time series, temperature difference between the four stations, time series of wind speed and time series of wind speed difference between the four stations from 2000 to 2005 were plotted and compared for the spring and summer seasons. The results indicate that, with increasing temperature difference between the four stations, the difference in speed also increases in 80% of the cases for the summer and in 66% of the cases in the spring season.In these two seasons, because of the decrease in the activity of atmospheric systems, the temperature difference between the two stations has a significant effect on improving the wind speed difference.Average wind speed difference in the statistical period of 2000-2005 at the stations is 0.7 m/s for the spring and 1.37 m/s for the summer season.
