Detection of Productive Oceanic Areas in the Arabian Sea and Persian Gulf Based on Reconstructed Satellite-Derived Sea Surface Temperature and Chlorophyll-a
Productive oceanic areas are rich in phytoplankton biomass, and they support a large degree of biodiversity. Therefore, it is necessary to detect productive oceanic areas to better understand their marine ecosystems. These areas are distinguished from other areas by their more frequently elevated sea surface chlorophyll-a concentrations (Chl-a) and colder sea surface temperatures (SSTs). Satellite remote sensing techniques are effective tools for ocean applications owing to their broad synoptic coverage and frequent observations. However, satellite data often include missing spatial gaps due to adverse weather conditions. In this study, monthly Moderate Resolution Imaging Spectroradiometer (MODIS)-Terra SST and Chl-a datasets were reconstructed using the Data Interpolating Empirical Orthogonal Functions (DINEOF) method to investigate their spatiotemporal variability and correlations in the Arabian Sea and the Persian Gulf (ASPG) region, which were divided into seven zones with three stations in each zone. Our results revealed that the Chl-a concentrations were much higher during the southwestern (SW) monsoon season and that the Chl-a concentration and SST exhibited a negative correlation at almost all of the stations. Furthermore, the frequency of positive Chl-a anomalies was calculated for each pixel, and the data points with frequencies of higher than 50% were regarded as productive oceanic hotspots. Maps of the average wind and Ekman transport in July were also produced and most of the hotspots were located in the upwelling regions in the ASPG, which confirms the impact of the upwelling associated with the wind in the productive oceanic areas. The results of this study provide a foundation for marine resource mapping and for effective usage of the ocean productivity in this region.