General pattern of sea level variation in front of Alexandria (Egypt) and its relationship to the wind pattern

摘要

Wind is an important factor affecting the observed sea level. This effect varies from one location to another, and depends largely on the morphometry and the position of the location itself. This paper investigates the relationship between the variations in the observed sea level at Alexandria Western Harbour and Abu-Qir Bay, of different morphometry, along Alexandria coast, and the wind pattern over the city. Simultaneous data sets of hourly sea level records at the two locations and of hourly measured wind over Alexandria from 01.01.2005 to 31.12.2006 are used. The WORLD TIDES package is used for a full sea level analysis. The wind pattern is described, and both wind rose and frequencies are also produced. Results reveal that tides in Abu Qir Bay can be classified as steric meteorological tides; greatly affected by the wind pattern than the astronomical impact. This is mainly attributed to the morphometry and open location of the Bay. In Alexandria Western Harbour, on the other hand, tides can be classified as astronomical tides mainly affected by the sheltered location and the constructions of the Harbour, which diminish the effect of the wind and, meanwhile, increase the impact of the celestial bodies on the recorded sea level.