Background and Theoretical Foundations: Climatic processes have widespread effects on the lives of humans and living organisms, particularly sea surface temperature (SST) changes, which play a key role in the distribution of heat from tropical to polar regions. These changes can influence weather patterns and climatic phenomena such as precipitation, wind, and air temperature. SST is affected by factors like ocean currents, wind speed, and temperature, and can impact regions far from the coastline. Various studies have shown that SST variations influence rainfall in different parts of the world, including Iran. These changes are particularly linked to events like El Niño oscillations and climate change in tropical areas. Investigating SST is crucial for predicting natural phenomena, managing crises, and improving weather forecasting models, as it helps to better understand the relationships between air and sea.
Methodology: In this study, sea surface temperature (SST) data were used to analyze temperature change trends. The data included SST retrievals from the ECMWF ERA-Interim database for the years 1980 to 2015, satellite remote sensing SST data from the NOAA AVHRR sensor for the years 1981 to 2006, and MWOI satellite data for 1998 to 2015. SST data with a spatial resolution of 0.125×0.125 degree were extracted from the ECMWF database for the period 1979 to 2015 on a daily basis. Monthly SST data were obtained using the AVHRR sensor, and MWOI microwave satellite datasets were used for marine biology monitoring and SST changes. To evaluate the SST trends, the non-parametric Mann-Kendall test was applied, which is capable of identifying non-linear trends and is resistant to outliers. This method is particularly effective for studying short-term changes and climatic patterns such as El Niño and La Niña.
Findings: This research analyzed the spatiotemporal changes of sea surface temperature (SST) in the southern waters of Iran from 1980 to 2015. Initially, SST data from the ECMWF ERA-Interim database were used to analyze SST trends on a monthly scale. The results showed significant seasonal variations in SST, especially in the Persian Gulf, which experiences higher temperature fluctuations due to its shallow depth and high salinity compared to the Sea of Oman and the Indian Ocean. During the warmer seasons, the Persian Gulf has higher temperatures due to the influx of colder river waters and its shallow depth, while the Sea of Oman and the Indian Ocean exhibit less temperature fluctuation. Mann-Kendall trend analysis revealed an increasing SST trend in the Persian Gulf in most months, with some areas showing decreasing trends. These temperature changes have varying effects on coastal ecosystems and marine life depending on the season. Additional analysis using AVHRR and MWOI satellite data indicated that the temperature differences between satellite data sets were due to differences in imaging conditions and measurement instruments. Overall, the study demonstrates that the Persian Gulf, due to its unique geographical features, experiences greater temperature fluctuations than other regions, and these changes can have significant impacts on local coastal and marine ecosystems.
Conclusion: This study examined the spatiotemporal changes of sea surface temperature (SST) in the southern waters of Iran. SST variations were analyzed using remote sensing data from the AVHRR and MWOI sensors, as well as ECMWF data. The results indicated that the Persian Gulf exhibits the greatest SST fluctuations, while the Indian Ocean shows the least variability. Factors such as depth, area, and salinity significantly influence SST fluctuations. Additionally, the analysis of temperature trends showed an increasing trend in most months of the year, with some months exhibiting a decreasing trend. The Persian Gulf, due to its high temperature variability, has a more fragile ecosystem compared to the Sea of Oman and the Indian Ocean. The satellite data analysis also showed that the Persian Gulf experiences greater temperature variations than the Indian Ocean, and these changes are less pronounced during the warmer seasons. |
.jpg)
.jpg)
