The effects of climate change on the thermal stratification of the Gulf of Oman

Abstract

Water temperature and thermal stratification have fundamental effects on marine environments, ecosystems, and water circulation patterns. Marine ecosystems are generally highly sensitive to thermal changes. Global warming can fundamentally alter oceanic temperature fields and thermal stratification(Cheng, 2019)(Cheng, 2019). Therefore, studying the effects of climate change on the thermal characteristics of the oceans and seas is vital. Using numerical modeling, and three Representative Concentration Pathway (RCP) scenarios, we studied the effects of global warming on the sea surface temperature and vertical thermal structure of the Gulf of Oman. Atmospheric data from the ERA5 and CORDEX models were used for recent past (1980–2000) and future (2080–2100) modeling, respectively. Results indicated that, in the future climate, the temperature across the upper 1000 m of the Gulf of Oman will increase. In summer, temperature increments in the surface mixed layer were estimated at + 1.9, + 2.5, and + 3.4°C for RCP 2.6, 4.5, and 8.5, respectively. Below the thermocline, the temperature increments were less than the ones in the surface mixed layer. In winter, future temperature increments in the surface mixed layer were + 1.2, + 1.6, and + 2°C for RCP 2.6, 4.5, and 8.5, respectively. The results indicated a stronger summer thermocline in the future with temperature gradients of 0.055, 0.057, and 0.06 °C/m in the RCP 2.6, 4.5, and 8.5, respectively, which could significantly reduce dissolved oxygen concentration in the lower layers. This study provides insights that can help develop adaptable strategies to manage and mitigate the harmful impacts of global warming on the Gulf of Oman.