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The DINEOF algorithm is a parameter free technique based on iterative EOF analysis that is used to calculate the missing data in a given satellite data set (without requiring any prior information). In this study, the DINEOF technique has been used to fill the gaps in chlorophyll-a data series in the Persian Gulf and Oman Sea. Level 3 data (4 km spatial resolution) of chlorophyll-a concentration obtained from MODIS sensor (2003- 2020) for the study area were used. In some of the images several gaps were found in different months of the year. Images with gap in the Persian Gulf and Oman Sea were reconstructed by rtsa.gapfill R-package and DINEOF algorithm in R software. The linear regression analysis was performed between the missing and reconstructed data, and also parameters such as RMSE, MSE, MAD and SNR were calculated to evaluate the validity and performance of the DINEOF algorithm. The maximum number of the gaps in data series were found in July. Hence, the images of July have been examined and reconstructed as the case study. The original maps of chlorophyll-a concentration showed that the maximum number of the gaps were in July 2009 and 2015. Evaluation of the results showed a high accuracy of DINEOF-reconstruction method (e.g. in July 2014, R² = 0.83, RSME = 0.34, MAD = 0.14, MSE = 0.10). The results showed that the implementation of the DINEOF algorithm (in R) to reconstruct the gaps in chlorophyll-a concentration images could serve as a rapid and efficient technique.

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Investigating the trend of temperature changes occurring in the Persian Gulf can be used to determine the pattern of climate change in the region and to study the impact of these changes on aquatic habitats in the Persian Gulf waters.  This study was carried out to investigate the changes in sea surface temperature and sea surface temperature anomaly in Kharg and Hendourabi islands by using Environmental Research Division's Data Access Program (ERDDAP) of National Oceanic and Atmospheric Administration (NOAA) and  daily sea surface temperature and sea surface temperature anomaly  were investigated over a 35-year period.The results showed that the average annual surface temperature increased by about 1 °C over 35 years in Kharg and Hendourabi Islands and the average annual sea surface temperature anomaly in these islands were increased by 2 °C. The slope of this increasing trend on Kharg Island was more severe than Hendourabi Island. The most significant bleaching event in the Persian Gulf occurred in 2016-2017, with the highest increase in temperature in 2017. As water temperatures continue to increase in the coming years, the living conditions of the Persian Gulf corals are likely to deteriorate, and only some resistant species can survive in the Gulf.