Decadal Trends in Red Sea Maximum Surface Temperature

The Red Sea is one of the warmest seas, exceeded only by the Arabian Gulf. Although it is considered a fast warming large marine ecosystem, its thermal regimes and evolution remain largely understudied. In this poster presentation we characterized the thermal regimes of the Red Sea at the basin scale, with a focus on the spatial distribution and changes over time of temperature extremes. Satellite data from AVHRR-OI (Advanced Very High Resolution Radiometer – Optimum Interpolation) recording SST (sea surface temperature) of the entire Red Sea from 1982 – 2014 was collated and annual maximum temperatures (T_max) were examined for each pixel at 0.25 degree resolution. Most of the basin did not show significant linear trends in temperature maxima over the last 33 years, this comprised about 70% of the area; of the 30% that did show significant trends, 100% pointed towards increased maximum temperature. The average warming rate for locations displaying significant warming averaged 0.15 – 0.55 ^oC decade^-1. The steepest and most significant increase in T_max was observed in the Northern Red Sea, including the Gulf of Suez and Gulf of Aqaba, with an average rate of increase in T_max of 0.45 – 0.55 ^oC decade^-1. As of yet, there is no clear pattern whether maximum temperatures are occurring earlier or later each year although there seems to be some indication that patches of the Southern Red Sea are experiencing temperature maxima 1 to 2 days earlier decade^-1. These results show that biota in the Northern Red Sea are experiencing significant ocean warming that may affect their future persistence.