Study of the isotopic composition of tropospheric water vapour in the vicinity of St. Petersburg
Ya.A. Virolainen, K.A. Shpak
Saint Petersburg State University, St. Petersburg, Russia
Keywords: water vapor cycle, ground-based IR Fourier spectroscopy, isotopic composition of water vapor
Abstract
Water vapour plays a key role in different climate-forming processes at various altitudes of the Earth's atmosphere. Water vapour isotopologues monitoring provides information on the atmospheric hydrological cycle. It helps to study the processes associated with evaporation and condensation that control the humidity in the troposphere and water exchange between the troposphere and stratosphere. For the first time, temporal variability of water vapor isotopologues (H2O and δD) in Peterhof in 2009-2020 were analyzed using ground-based measurements of solar IR radiation by the Bruker IFS 125HR Fourier spectrometer. For both H2O and δD, the maximum values occur in summer, the minimum - in winter, while the largest variability of H2O is observed in summer, and δD - in winter months due to the climatic features of St. Petersburg, i.e. the origin and history of incoming air masses. The database of water vapour isotopic composition in the vicinity of St. Petersburg can be used in models of the general circulation of the atmosphere to improve the accuracy of weather forecasting and long-term changes in the regional climate.
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