Mean sea level rise acceleration on the Polish Coast during the last 48 years  <B>Mean sea level rise acceleration on the Polish Coast during the last 48 years</B><P>M. Kalas</B><I><P> Institute of Meteorology and Water Management, Maritime Branch, Gdynia</I><P> Abstract<P> An increase of mean sea level was obtained based on the analyze of the long annually mean sea level records from tide gauges along the Polish coast. Coefficients for linear trend equation as well as coefficients for parabolic trend equation were established. The first one indicate mean annually rise of sea level, but the second one shows the sea level rise acceleration (i.e. deviation from a purely linear rise) and indicate a predicted rapidity of future mean sea level rise. Seven complete tide gauges records for the 48year period (19471994) (for Swinoujscie, Kolobrzeg, Ustka, Wladyslawowo, Hel, Gdansk and Gdynia) were analised and for all of them evidently positive values of linear trend coefficient are found, from 0.103 cm/yr for Kolobrzeg to 0.253 cm/yr for Gdansk. For this period non zero, positive values for parabolic trend coefficients are visible, from 0.003 cm/yr2 for Ustka to 0.011 cm/yr2 for Swinoujscie, which indicate an observed acceleration of mean sea level rise on the Polish coast. For comparison much longer record of yearly mean sea level values for Swinoujscie for the period of 182 years (18111993) was analyzed. When records of annually mean sea level values (for the periods: 18111845, 18461900 and 1901 1946) were analised it was obtained that the values for acceleration coefficients of sea level rise are equal to 0.000 mm/yr2 for all this cases. This show that the last half century a significant acceleration of mean sea level rise on the Polish coast is observed.<P>