Baltic Sea water tritium and stable isotopes in 2016–2017^*

ABSTRACT

Water samples from the different basins of the Baltic Sea and North Sea were collected during four cruises taken place in 2016–2017. Altogether 60 water samples for ³H activity concentration and 120 water samples for stable isotopes ratio (δ¹⁸O and δ²H) were analysed. Exceptionally strong inflow activity from North Sea to the Baltic Sea occurred prior our surveys. The data obtained enabled comprehensive evaluation of tritium and stable isotopes distribution in waters of Baltic Sea and contributing inputs, including riverine and atmospheric freshwater flux and saline water inflow through the Danish Straits. By comparing with the previous studies, we noticed a tendency toward an increase in the δ¹⁸O and δ²H values of zero-salinity component over time, which may be due to climate change. In the case of tritium, the influence of artificial sources has also been noticed.

KEYWORDS:

• Baltic Sea
• hydrogen-2
• hydrogen-3
• isotope hydrology
• oxygen-18
• salinity
• zero-salinity component

Acknowledgments

We are grateful to our colleagues involved in analytical works and research vessels crews for assistance with the sampling. We would like to thank two anonymous reviewers whose constructive comments have significantly improved the paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Olga Jefanova http://orcid.org/0000-0002-1183-3679

Žana Skuratovič http://orcid.org/0000-0002-5090-3932

Tõnu Martma http://orcid.org/0000-0001-5894-7692

Notes

* Originally presented at the IAEA Symposium on Isotope Hydrology 2019, Vienna, Austria, 20–24 May 2019.