The influence of atmospheric circulation on the water level on the southern coast of the Baltic Sea

摘要

The research focused on the relationships between atmospheric circulation patterns and the water level on the southern coast of the Baltic Sea. Monthly values of water levels were used, recorded between 1961 and 2010 in Wismar, Warnemunde, Sassnitz, winoujcie, Koobrzeg, Ustka and Wadysawowo. To establish and examine the relationships between the water levels (dependent variable) and the number of days of atmospheric circulation patterns (independent variable), the correlation and regression analysis were conducted. The strongest relationships occur in the months of the cold season (November-March), especially in January, February and March, with the statistical significance of =0.01 (usually =0.001), mainly due to considerable atmospheric circulation activity. Relationships with the onshore circulation (W+NW+N) are slightly stronger than with the seaward circulation (E+SE+S). The intensity of these relationships grows eastwards (Ustka, Wadysawowo), where the water levels are higher, their amplitudes and standard deviations are larger and the coastal exposure is more favourable. It is where in winter (December-February) the correlation coefficients exceed |0.80|. The relationships in the months of the warm season (April-October) are visibly weaker, especially with the E+SE+S circulation in the west part of the southern coast of the Baltic Sea (Wismar, Warnemunde), where they are statistically insignificant. The asynchronous relationships of water levels with atmospheric circulation are usually weaker than the synchronous ones. However, on the west coast (Wismar, Warnemunde), the asynchronous relationships, especially with the E+SE+S circulation with 1-month delay, are usually stronger than the synchronous ones. They may have a prognostic value. The longer the intervals between the studied variables are, the weaker the relationships become.