The Interannual Variability of Sea Surface Temperature in the Red Sea From 35 Years of Satellite and In Situ Observations

Abstract

AbstractFalling between the dynamics of the seasonal cycle and expressions of longer‐term trends, the interannual variability of sea surface temperature (SST) in the Red Sea has not received enough attention. With multiple decades of satellite SST observations with spatial resolution capable of resolving patterns of variability within the Red Sea, the time has come for a description and diagnosis of the observed interannual variability of SST in this important semienclosed sea. While interannual variability of SST occurs throughout the Red Sea in both summer and winter, the greatest variability is found in the northern Red Sea during winter. Objective analysis reveals two dominant statistical modes of interannual variability of Red Sea SST: a whole‐sea mode described by general warm or cool anomalies throughout the Red Sea (∼60% of total variance), and a meridional gradient mode of opposing SST anomalies in the northern and southern Red Sea (∼20% of total variance). The warm phase of the whole‐sea mode corresponds to warm surface air temperature anomalies extending across the broader region and local surface wind anomalies opposite to the mean low‐level circulation. The whole‐sea mode is found to be a regional response to remote forcing by the East Atlantic/Western Russia (EAWR) pattern. The gradient mode, on the other hand, is a manifestation of superimposing (and statistically independent) remote impacts of El Niño‐Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO) whereby ENSO drives SST anomalies in the southern Red Sea and the NAO drives SST anomalies in the northern Red Sea.