Modeling the response of the mediterranean sea level to global and regional climatic phenomena

Abstract

Fluctuations of the sea level pose an issue of emerging importance, especially after scientific research revealed a clear rising trend. Since the early 80's, a new technique, satellite altimetry, resulted in an abundance of sea surface height measurements and these data are crucial to both oceanographic and geodetic applications. This work presents the results of a correlation study of the Sea Level Anomaly (SLA) with global and regional climatic phenomena that influence the ocean state as well. For this reason, three correlation indexes have been examined. The first one is the well-known Southern Oscillation Index (SOI) corresponding to the ocean response to El Niño/La Niña-Southern Oscillation (ENSO) events. The next index is the North Atlantic Oscillation (NAO) index, which corresponds to the fluctuations in the difference of atmospheric pressure at sea level between the Icelandic low and the Azores high. The last index is the Mediterranean Oscillation Index (MOI), which refers to the fluctuations in the difference of atmospheric pressure at sea level between Algiers and Cairo. The raw data used were SLA values from Jason-1 and Jason-2 satellite altimetry missions for a period of thirteen years (2002-2014) within the entire Mediterranean Basin. Regional multiple regression and correlation analyses between sea level anomalies and these indexes were carried out in order to detect and model correlations between the Mediterranean sea level and the aforementioned global and regional climatic phenomena.

Keywords

• sea level
• altimetry
• regression analysis
• pca
• mediterranean sea