Decadal variability and recent summer warming amplification of the sea surface temperature in the Red Sea

Abstract

Under climate change, regional Sea Surface Temperature (SST) changes are a crucial factor affecting marine ecosystems, which thrive only within a certain thermal limit. Thirty-seven years of monthly gridded Optimum Interpolation SST data from 1982 to 2017 were used to investigate the decadal variability of this parameter in the Red Sea during the summer season, in relation to large-scale climate variability. We identified a non-uniform warming trend beginning around the mid-1990s over the whole basin, with a predominant amplified warming over the northern half (0.04°C year-1), which is approximately four times higher than the global warming trend, but much weaker warming over southern end (0.01°C year-1). It was found that the Atlantic Multi-Decadal Oscillation (AMO) and the Silk Road Pattern (SRP) are shaping the RS SST, since their phase shift concurs with the timing of the significant non-uniform warming over the basin. The AMO triggers the SRP-related vertical and horizontal temperature advection that leads to opposite changes in the SST. We suggest that warming is amplified over the basin due to an overlap with global warming signals. Our results have important implications for interannual and decadal SST predictions based on the predictability of AMO and SRP patterns.