Sea level variation in the Red Sea based on SODA data

Abstract

In this study we investigate the sea level variation in the Red Sea focusing on wind stress setup. 50-years dataset from 1957 to 2007 of sea level and wind stress from Simple Ocean Data Assimilation (SODA) data version 2.0.2-4 are used, which are taken from Carton and Giese (2007). The Hanish Sill (located in 13.25ºN) represents the reference point, in which the sea level, wind stress and steric effect compare to this point. A correlation coefficient is used for the northern, central and southern Red Sea during three seasons: summer, early winter and late winter. A weak correlation between sea level and wind stress is observed in all periods and locations, except in the central basin where it records a correlation of -0.66 during the late winter. The seasonal anomaly difference of sea level with reference to the Hanish Sill shows clearly an annual cycle, with the maximum is during August and September of about 5 cm, and the minimum is during February and March of about -5 cm. The mean sea level profile reflects a strong gradient from the south to the north, 0.13 to -0.04 m, respectively, with a bulge located in the central basin of about 0.16 m. The seasonal anomaly difference of wind setup compared to the Hanish Sill has a strong semi-annual cycle especially in the northern basin with range of about 14 cm. The seasonal anomaly difference of steric effect, which represents the residual term, also reflects a semi-annual cycle in the northern basin with 9 cm range. However, in the central and southern, the annual cycle appears the dominant one with 8 cm range.