The most informative data comes from the Baltiysk/Pillau
station, where water levels have been measured since 1840. In the period from 1840 to 2008 there were several cycles of water level rise and fall, each lasting for up to four decades. For the period from 1961 to 2008 we perceive similar tendencies in water level fluctuations for our three lagoons, as expressed by the 11-year moving average. These are repeated cycles of rise and stabilization (Figure 2): 1950–1960 (stable rise), 1961–1979 (stabilization), 1980–1991 (stable rise), 1992–2002 Y-27632 order (stabilization). From a comparison of the long-term monthly mean water level changes during separate thirty-year periods (1961–1990 and 1979–2008) at the Klaipėda stations in CL (Figure 3a) and find more at Zingst in DZBC (Figure 3b), it was inferred that the recent sea level rise was greater in all the seasons. The sea-level increase took place
throughout the year, although this process was more intensive in the period from January to March. In addition, the variability of the monthly mean sea-level in the cold periods is more significant than in the warm periods. A non-uniform ‘shift’ (towards greater values) of the mean annual seasonal variation curve for 1979–2008 by 3–12 cm for CL and 3–7 cm for DZBC in comparison with the similar curve for 1961–1990 corresponds to climate changes, which manifest themselves differently at different seasons. The seasonal dependence of trend characteristics is much more pronounced for CL than for DZBC (Figure 4a): the rate of water level increase is greatest in January–March (up to 0.8 mm year−1) and June (nearly 0.5 mm year−1), but less in late autumn. For DZBC the trend is nearly 2 mm year−1 for the whole year except February–March (3–4 mm year−1) and December (no increase at all). The maximum determination
coefficient (Figure 4b) for these linear regressions in May–June for CL and June–September for DZBC indicates that the level rise in these months is almost linear. Regression analysis results show that the water temperature in the lagoons is rising at a faster rate than on Baltic Sea shores. According to the assessment, the warming trend of 4-Aminobutyrate aminotransferase the mean surface water temperature in the Curonian lagoon and in the Lithuanian coastal waters of the Baltic Sea rate was about 1.4°C in the period of 1961–2008 (Table 3). The warming trend of the mean surface water temperature in the Curonian Lagoon was 0.03°C year−1 in 1961–2008, and ca 0.05°C year−1 in 1977–2002 (CL and VL), and 0.06°C year−1 in the DZBL (1977–1992). A more detailed comparison between lagoons was impossible, because of the lack of data and the unequal periods. The rise in water temperature and water level in the lagoons is due to changes in the air temperature (Figure 5) and atmospheric circulation.