Correlation of the Stable Hydrogen and Oxygen Isotopes with the Atmospheric Humidity from Cluj-Napoca, Romania

Abstract

Within the water cycle, the temperature at the location where vapor condenses to precipitation has been heralded as a primary controlling factor in the fractionation of stable isotope in precipitation. Because atmospheric temperature dictates the pressure of aqueous vapor in atmosphere and the water vapor pressure controls the isotopic composition of atmospheric water vapor, changes in the temperature dictate different rates of fractionation. This study was focused on the analysis and correlation of isotopic compositions of hydrogen and oxygen 18 in samples from atmospheric humidity with local rainfall in Cluj-Napoca, Romania. The isotope analysis of atmospheric humidity can greatly support in tracking the hydrological cycle through fingerprinting the source of water vapors, its transport, and its condensation through direct analysis. These measurements may be further used to understand the factors controlling the water and energy balance of the atmosphere and guide new studies of clouds and the atmospheric hydrology. The time series for δ²H and δ¹⁸O values point out both the seasonal variations that have increased the amplitude reflecting the continental character of the local climate, as well as dramatic variations of isotopic content of successive precipitation events, emphasizing the anomalous values.

Keywords:

• Stable isotopes
• liquid-water isotope analysis
• atmospheric humidity
• rainfall

Additional information

Funding

This research was financially supported by the MCI, Nucleu-Program, project PN19 35 02 02. Unitatea Executiva pentru Finantarea Invatamantului Superior, a Cercetarii, Dezvoltarii si Inovarii.