Long-term change of surface temperature in water bodies around Iran – Caspian Sea, Gulf of Oman, and Persian Gulf – using 2001–2015 MODIS data

Abstract

To answer the question “what has changed the surface temperatures of water bodies around Iran under climate change conditions,” Moderate Resolution Imaging Spectroradiometer (MODIS) sea surface temperature (SST) data with 9.2-km spatial resolution and monthly time step were evaluated. A significant increasing trend was obtained using Pearson’s correlation coefficient and Mann-Kendall trend test on data from the Caspian Sea (June) and the Southern Gulfs (September). High correlations of 0.69 and 0.97 between remotely sensed data and ERA-Interim reanalysis data were also obtained for June and September, respectively. To assess the impact of some climatic parameters on SST variability in those two months, zonal and meridional wind at 10 m, wind speed at 10 m, air temperature at 2 m, and mean sea level pressure were evaluated. High correlations between meridional wind and the Southern Gulf SST, and meridional wind and Caspian SST were −0.86 and 0.75, respectively. Moreover, the results showed an important role of air temperature (0.96) and sea level pressure (−0.77) in the rising temperature trends of the Southern Gulfs. Wind speed was also detected in both regions as a booster of the trend.