Fig. 3: Time series of δ2H / δ18O values in water samples collected between 26th March 2020 to 16th March 2021 at A. P. Møller Skolen (APM Skolen), Schleswig (Kleine Breite, Schlei; sampling point A; Fig. 2a), in comparison to salinity, water temperature, pH. Data of daily mean values of water discharge derived from the major inflowing river Füsinger Au (LLUR, 2022). Major Baltic Sea salt inflow events at Great Belt and Øresund from (V. Mohrholz, 2018).