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).