Quantifying the Mean Sea Level Change at the Gulf of Finland Coast Caused by the Realistic Portion of the Global Warming Forcing

Quantifying the coastal mean sea level change causing by the winter positive phase of the North Atlantic oscillation index NAO+ at the Gulf of Finland coast is of high priority for detecting and predicting the global warming impact in this region. Both boreal winter months and season of three long-term data station series of the coastal mean sea levels and the NAO indices were linked for two cases, i.e.: different periods and the 1977-1994 period. This study is dedicated to: (1) Detecting the exclusive impacts of the NAO+; (2) Estimating the significant standard bivariate linear regression models; (3) Calculating the climatic linear trend coefficient by using three methods (OLS, GLS, Theil-Sen); (4) Correcting the mean sea level series anomalies by using the significant linear regression equations as a function of NAO+ anomalies, over the period 1977-1994; (5) Calculating the realistic linear trend caused as a function of NAO+ for period 1977-1994 in the context of the realistic portion of the global warming. The results reveal that, the NAO+ manifests their impacts on the coastal mean sea levels and its contribution in the configured linear trends. The realistic linear changes have detected and predicted. The Gulf of Finland coast showed the warmest regions in the context of the realistic portion of the global warming during the winters of the period 1977-1994.