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.

Atmospheric Forcing of the High and Low Extremes in the Sea Surface Temperature over the Red Sea and Associated Chlorophyll-a Concentration

“…These results support the previous finding of Alawad et al (2020) [19] that the whole RS has experienced a nonuniform warming trend since 1996, which has amplified over the northern half to reach 0.04 • C year −1 -approximately 4 times higher than the global trend.…”

“…In addition to this, the annual mean SST shifted from 27.4 • C in 1985-1993 to 28.1 • C in 1994-2007 [18]. Recently, Alawad et al (2020) [19] found that the warming trend over the northern half of the RS is 0.04 • C year −1 , which is almost 4 times higher than the global trend, and over the southern half it is 0.01 • C year −1 , while the whole basin trend is 0.029 • C year −1 [20]. As a consequence of this intense warming trend, the growth of central Red Sea coral has decreased [21,22], as has the chlorophyll concentration over the northern half of the basin [23].…”

Atmosphere-Ocean Coupled Variability in the Arabian/Persian Gulf

“…Further analysis of the lead-lag correlation revealed a 1-3 month lag, where the AMO index was found to lead the PC time series of mode 1 (Figure 11A). The warming of the Gulf 's SST in response to the AMO warming peaks was consistent with the findings of Alawad et al (2020) within the Red Sea; it is likely attributable to changes in the upper troposphere (200 hPa) meridional winds (namely the Circum-Global Teleconnection; Ding and Wang, 2005). These changes impose warm air temperatures (Lu et al, 2002;Hong et al, 2017) across the Eurasian continents.…”

Appraisal of coral bleaching thresholds and thermal projections for the northern Red Sea refugia

“…For example, the Red Sea is influenced by the Atlantic Multidecadal Oscillation (AMO) and higher warming trends coincide with the positive phase of this oscillation, and thus the SST trend is amplified (Krokos et al, 2019). Alawad et al (2020) supported this notion and revealed that current warming for the Red Sea is largely amplified by the overlap of warming signals between the AMO and the Silk Road Pattern (SRP) in the non-uniform warming trends over the Red Sea basin, and thus might in fact decrease over the next few decades. Although it should be noted that Mann et al (2020) did not support the presence of an internally generated multidecadal oscillatory signal in the last millennium.…”