Variations of δ¹⁸O and δ²H values of precipitation in Moscow from 2017 to 2019

To reveal variations in the isotopic composition of O and H in the atmospheric precipitation in Moscow and the processes influencing the isotope composition, all events of precipitation in 2017–2019 were sampled at the Meteorological Observatory of the Moscow State University: 158 samples in 2017, 119 samples in 2018 and 143 samples in 2019. The study is a prolongation of continuous measurements of the isotope composition of precipitation, started by authors in 2014. The study of the isotope composition of precipitation at the MSU Meteorological Observatory was supported by the IAEA and became a part of the Global Network of Isotopes in Precipitation (GNIP) database. It has been found that the intra–annual variability of the isotope composition of precipitation has a pronounced seasonality. The most isotopically heavy precipitation falls from May to August, and the most isotopically light precipitation at December-February, mainly due to seasonal air temperature variations. The ratio of the average monthly δ¹⁸O values in precipitation and air temperature for the study period varied from 0.34 to 0.39‰/°C, which is consistent with the previously obtained data for precipitation in Moscow. The δ²H–δ¹⁸O ratio in precipitation was close to that of the Global Meteoric Water Line, pointing to the equilibrium conditions during precipitation formation. It was established that in the summer months isotopic composition is significantly influenced by undercloud evaporation. The deuterium excess values in precipitation are not markedly seasonal; however, lower d_exc values (below the 3-year average of 11‰) are typical for the summer months (July–August). It is most likely due to undercloud evaporation in conditions of low relative humidity and high air temperatures. Higher d_exc values (above 11‰) prevailed from October to April.

1. Aemisegger F. On the link between the North Atlantic storm track and precipitation deuterium excess in Reykjavik, Atmospheric Science Letters, 2018, vol. 19, iss. 12, p. 1–9, DOI: 10.1002/asl.865.

2. Araguas-Araguas L.J., Diaz Teijeiro M.F. Isotope composition of precipitation and water vapour in the Iberian Peninsula, Isotopic composition of precipitation in the Mediterranean Basin in relation to air circulation patterns and climate, Final report of a coordinated research project, 2000–2004, 2005, p. 173 –191.

3. Chizhova Ju.N., Eremina I.D., Budantseva N.A., Surkova G.V., Vasil’chuk Yu.K. Concentration of 18О in precipitation over Moscow in 2014, Russian Meteorology and Hydrology, 2017, vol. 42, no. 1, p. 54–63, DOI:10.3103/ S1068373917010071.

4. Craig H. Isotopic variations in meteoric waters, Science, 1961, vol. 133(3465), p. 1702–1703.

5. Dansgaard W. Stable isotopes in precipitation, Tellus, 1964, no. 16, p. 436–468, DOI: 10.1111/j.2153-3490.1964.tb00181.x.

6. Duliński M., Różański K., Pierchała A. et al. Isotopic composition of precipitation in Poland: a 44-year record, Acta Geophys, 2019, vol. 67, p. 1637–1648.

7. Fricke H.C., O’Neil J.R. The correlation between 18O/16O ratios of meteoric water and surface temperature: its use in investigating terrestrial climate change over geologic time, Earth and Planetary Science Letters, 1999, vol. 170, no. 3, p. 181–196, DOI: 10.1016/s0012-821x(99)00105-3.

8. Fröhlich K., Gibson J.J., Aggarwal P.K. Deuterium excess in precipitation and its climatological significance, Proceedings of the study of environmental change using isotope techniques, International Atomic Energy Agency, Vienna, 2002, p. 54–66.

9. Fröhlich K., Kralik W., Papesch W. et al. Deuterium excess in precipitation of Alpine regions – moisture recycling, Isotopes in Environmental and Health Studies, 2008, vol. 44, no. 1, p. 61–70, DOI: org/6170.10.1080/10256010801887208.

10. Gat J.R., Mook W.G., Rozanski K., Fröhlich K. Environmental isotopes in the hydrological cycle: Principles and applications, Paris, UNESCO, 2001, vol. 2.

11. Hager B., Foelsche U. Stable isotope composition of precipitation in Austria, Austrian journal of Earth Sciences, 2015, vol. 108, p. 2–14, DOI: 10.17738/ajes.2015.0012.

12. Hatvani I.G., Smati A.E., Erdélyi D. et al. Modeling the spatial distribution of the meteoric water line of modern precipitation across the broader Mediterranean region, Journal of Hydrology, 2023, vol. 617, part B, 128925, DOI: 10.1016/j.jhydrol.2022.128925.

13. Klein E.S., Cherry J.E., Young J. et al. Arctic cyclone water vapor isotopes support past sea ice retreat recorded in Greenland ice, Science Reports, 2015, no. 5, p. 10295.

14. Nagavciuc V., Perşoiu A., Bădăluţă C.-A. et al. Defining a precipitation stable isotope framework in the wider Carpathian Region, Water, 2022, vol. 14, p. 2547, DOI: 10.3390/w14162547.

15. Pfahl S., Sodemann H. What controls deuterium excess in global precipitation? Climate of the Past, 2014, vol. 10, p. 771–781, DOI: 10.5194/cp-10-771-2014.

16. Puscas R., Feurdean V., Simon V. Stable isotopes composition of precipitation fallen over Cluj-Napoca, Romania, between 2009–2012, AIP Conference Proceedings, 2013, 1565, 308, DOI: 10.1063/1.4833751.

17. Putman A.L., Fiorella R.P., Bowen G.J., Cai Z. A global perspective on local meteoric water lines: meta-analytic insight into fundamental controls and practical constraints, Water Resources Research, 2019, vol. 55, no. 8, p. 6896– 6910, DOI: 10.1029/2019WR025181.

18. Rozanski K., Araguás-Araguás L., Gonfiantini R. Relation between long-term trends of oxygen-18 isotope composition of precipitation and climate, Science, 1992, vol. 258, p. 981–985, DOI: 10.1126/science.258.5084.981.

19. Varlam С., Duliu O.G., Ionete R.E., Costinel D. Time series analysis of the δ2H, 18O and dexcess values in correlation with monthly temperature, relative humidity and precipitation in Râmnicu Vâlcea, Romania: 2012–2018, Geological Society, London, Special Publications, 2021, vol. 507, iss. 1, p. 77–89, DOI: 10.1144/SP507-2020-56.

20. Vasil’chuk Yu.K., Budantseva N.A., Vasil’chuk J.Yu., Eremina I.D., Bludushkina L.B. Variacii znachenij δ18O i soderzhanie vodorastvorimyh solej v atmosfernyh osadkah Moskvy v 2014–2016 gg. [Variations of the δ18О values and water-soluble salts in precipitation in Moscow during 2014 to 2016], Vestn. Mosk. un-ta, Ser. 5, Geogr., 2021, no. 2, p. 35–43. (In Russian)

21. Vlasova L.S., Ferronskii V.I. Water transport over Western Europe and its correlation with climate variations based on precipitation isotopic composition, Water Resources, 2008, vol. 35, no. 5, p. 502–521.

22. Vreča P., Kanduč T., Žigon S., Trkov Z. Isotopic composition of precipitation in Slovenia, Isotopic composition of precipitation in the Mediterranean Basin in relation to air circulation patterns and climate, Final report of a coordinated research project, 2000–2004, 2005, p. 157–173.

23. Zykin N.N., Tokarev I.V., Vinograd N.A. Monitoring of stable isotopes (δ2H, δ18O) in precipitations of Moscow city (Russia): Comparison for 2005–2014 and 1970–1979 periods, Vestnik of Saint Petersburg Un-ty, Earth Sciences, 2021, vol. 66, no. 4, p. 723–733, DOI: 10.21638/spbu07.2021.405.