Measurements of stable water isotopes (δ Deuterium, δ18O, δ13C) from the water column in the Fram Strait from the POLARSTERN cruises PS92 (ARK-XXIX/1, TRANSSIZ) and PS93.1 (ARK-XXIX/2.1) in May to July 2015. δ Deuterium and δ18O were measured with a Picarro 2130i CRDS System, δ13C with a Finnigan MAT 252 gas isotope ratio mass spectrometer with Gasbench 2 at MARUM - Center for Marine Environmental Sciences. The measurements were conducted in 2020/2021.

δ Deuterium and δ18O measurements were conducted measuring 9 injections of 9 µL each. The given result is the average of the last three injections. The nominal machine standard deviation is 0.03 for ∂18O and 0.3 for ∂D, yet this is for freshwater samples, so the actual standard deviation is higher owing to salinity. CH4 concentrations might disturb the isotope signal. 123 of the 297 water samples used for δ Deuterium and δ18O measurements were filtered before the measurement, which is indicated in a separate column in the data. Filtration was done with Sartorius microsart filter.The standard deviation of the house standard (Solnhofen limestone) over measurements of δ13C was 0.04 ‰.