Известия Томского политехнического университета: Инжиниринг георесурсов (Feb 2019)

ISOTOPIC COMPOSITION OF PRECIPITATION IN ALTAI FOOTHILLS: OBSERVATION AND INTERPOLATION DATA

  • Natalia S. Malygina,
  • Alla N. Eirikh,
  • Nadezhda Yu. Kurepina,
  • Tatiana S. Papina

DOI
https://doi.org/10.18799/24131830/2019/2/91
Journal volume & issue
Vol. 330, no. 2
pp. 44 – 54

Abstract

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Relevance. In recent years, the ratios of oxygen and hydrogen stable isotopes in precipitation obtained from the Global Network of Isotopes in Precipitation (GNIP) have been widely used as reliable markers of current and predicted climatic and hydrological changes. However, for the vast territory of Russia such data sets are essentially limited both in space and in time. One of the most promising study areas is the Altai foothills subjected to significant hydrological and climatic changes in the last decades. The aim of the research is to assess the changes in isotopic composition of precipitation sampled in the Altai foothills during the study period in accordance with the GNIP recommendations, and to compare the assessment results with the interpolated GNIP data on the adjacent territories. Methods. Precipitation was sampled in accordance with the GNIP criteria. The synoptic analysis was supported by the meteorological data from the nearest «Roshydromet» weather station. The isotopic analysis of precipitation was performed by means of laser absorption IR spectrometry on PICARRO L2130-i device. The obtained results were compared with the interpolated GNIP data for the Altai foothills calculated with the use of ISOtopic GRIdded Rainfall Data Software (ISOGRIDS) and Isoscapes Modeling, Analysis and Prediction (IsoMAP). Results. The analysis of isotopic composition of precipitation sampled in accordance with GNIP requirements in the Altai foothills in 2016 indicated its significant variation. The comparison of isotopic composition of precipitation simultaneously sampled in the study area using two schemes (daily and monthly sampling) shows good correlation; under limited conditions, just monthly sampling is probable. The comparison of weighted average monthly values of isotopic composition of the observed atmospheric precipitation and of that calculated by IsoMAP suggests maximum differences in February and September that is true for comparison with ISOGRIDS data as well. The revealed differences are related to the synoptic peculiarities of 2016, namely, atypically stable positive temperature in February and insignificant precipitation recurrence (more than 1 mm) in September.

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