Satellite-Derived Detection of Caspian Sea Temperature Fronts as An Index of Hydrophysical Phenomena (Internal Waves, Seabed Slope, and Eddy).

Document Type : Original Research Article

Authors

1 M.Sc. of Physical Oceanography, Faculty of Environmental and Marine Sciences, University of Mazandaran, Mazandaran, Iran

2 Associate professor of Physical Oceanography, Faculty of Environmental and Marine Sciences, University of Mazandaran, Mazandaran, Iran. Email: m.akbarinasab@umz.ac.ir

3 Assistant professor, Faculty of Environmental and Marine Sciences, University of Mazandaran, Mazandaran, Iran.

Abstract

Sea surface temperature fronts are crucial in studying climate change, air-sea interaction, fisheries production, and oceanography. These fronts are formed due to various oceanographic features, such as bathymetry, upwelling, the convergence of surface waters, and internal waves. To identify the temperature fronts of the Caspian Sea, researchers in this study used remote sensing techniques. The SIED method was employed, which is considered one of the best techniques for detecting temperature fronts in satellite images. This method works by analysing the temperature histogram of surface water masses, making it more reliable than other methods. The study analyzed MODIS images over a period of five years to establish the relationship between physical phenomena and temperature fronts. The results confirmed that the traits of the temperature fronts of the Caspian Sea are variable in time and place, and the maximum presence of temperature fronts inside the northern half of the Caspian Sea belongs to November and December, while in the southern half, it belongs to January. Middle Caspian Sea temperature fronts correspond to inner waves, particularly in February, May, and March. On the other hand, the temperature fronts are shaped greater at a distance from the coast, wherein there's a steep bed and in deep areas, the variety of diagnosed fronts is small. The presence of mesoscale eddies inside the Middle Caspian is likewise one of the motives for growing temperature fronts at the eastern and western coasts of the Middle Caspian.

Keywords

Main Subjects