Survival of High Latitude Fringing Corals in Extreme Temperatures: Red Sea Meteorology

Abstract

Zaki's Reef is located in the Gulf of Suez, a narrow portion of the Red Sea, with exceptionally dry and hot climate and lacks almost all scientific data. This research intends to describe the area's unique climatology, which may reveal correlations between the reef's existence at high latitude and extreme climate conditions. Air temperature at Zaki's Reef fluctuated between 0.3 and 58.6oC with a daily range of 25oC and annual mean of 22.1oC ±0.075. Spectral analysis revealed half day, daily and yearly return periods, all of which have shown that daily and half daily cycles are dominating the local climate with amplitudes of approximately 5oC. Frequency histograms revealed a bimodal signal, one peak at 14-15oC and a second peak at 32-33oC, both represent nighttime and daytime temperatures half-day cycle. Meteorological data collected at Zaki's Reef were also compared to Hurghada's and Ismailia's, 400 and 200 km south and north of the study site, respectively, to reveal any anomalies. Although air temperature daily means at Zaki's Reef were similar to Hurghada's, maximum daily means exceeded Hurghada's by 7oC, while minimums were almost equal to Ismailia's. Unexpected temperature trends and short distance between mountain range and Zaki's Reef, prompted us to hypothesize that a Foehn wind may be responsible for the extremely high air temperatures. Air parcel trajectory model results further verified that local wind patterns matched signatures of a Foehn wind. The observed warmer than normal air temperatures may be responsible for securing the survival of these northernmost subtropical coral reefs.