Meteorological forcing and sea level variability in the Aegean Sea

The effect of atmospheric pressure and surface wind vector on sea level variability in the Aegean Sea is investigated. Daily values of sea level, atmospheric pressure, and surface wind covering the period 1984–1987 from five stations are analyzed. Principal component (PC) analysis is used to extract the spatially coherent signal from the sea level and atmospheric pressure time series, while rotary principal component analysis is used to extract the coherent part of surface wind. The first PC modes are subsequently used in multiple regression analysis in the frequency domain in order to examine the dependence of sea level fluctuations on each of the parameters. The response of sea level to atmospheric pressure is found to be frequency dependent. The response is overisostatic for lower frequencies and becomes underisostatic for higher frequencies approaching isostasy only at the limit of analysis (0.5 cycles/day). The contribution of the first principal wind component is found to be very small.