5.3 Salinity – isotope correlation
The spatial trends in water isotopes as visualized in Fig. 7 are illustrated as correlation crossplots between δ-values and salinities in Fig. 8. Those reveal an almost linear correlation (R20.99 δ2H and 0.98 δ18O; p < 0.0001) for samples taken along the Schlei in March 2020, and significant correlation (R2 0.75 δ2H and 0.77 δ18O; p < 0.0001) for DZBC and Rügener Bodden samples. The isotope amplitude over ca. 20 salinity units accounted for ca. 30 ‰ δ2H and 5.5 ‰ δ18O.
In contrast, samples from July 2020 reveal hyperbolic correlations between the two parameters (Fig. 8). Here, δ-values reach a plateau of maximum values for salinities >7. For some samples, a reversal towards lower δ-values with increasing salinities is observable. A similar trend is observable in samples from June 2019, which were taken in lower spatial resolution (Fig. 8).