Exploring SST and Chlorophyll-a Anomalies in the Arabian Gulf: A Google Earth Engine Analysis

Changes in sea surface temperature (SST) and chlorophyll-a (Chl-a) pose problems for the management of ocean resources and are essential for understanding the dynamics and variability of marine ecosystems. This study examined spatiotemporal variation of SST and Chl-a in the Arabian Gulf from 2003 to 2023, using Level-3 MODIS Aqua data on the Google Earth Engine (GEE) platform. In addition, for identification of significant changes and deviations trend and anomaly detection were carried out. The eastern Arabian Gulf has higher SST values than the western half and Chl-a distribution was high in shallow coastal areas, especially in the eastern, western, and southern parts of the Gulf. There was a negative association between SST and Chl-a, with SST showing an increasing trend while Chl-a exhibited declining trend. SST anomalies showed substantial shift from the long-term trend, with negative extremes in 2005, 2008, and 2009. Positive anomalies were perceived in the years 2017, 2019, 2021, and 2023, with the greatest anomaly in 2019 (18.28-36.44°C). In recent years, these anomalies indicated a rising trend. On the contrary, Chl-a displayed positive anomalies in year 2008 (0.83-17.46 mg/m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup>) and 2009 (0.82-19.63 mg/m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup>); from 2019 onwards, however, there was a drop, indicating negative anomalies.