Interannual Variations in Stable Isotopes of Atmospheric Water in Arid Central Asia Due to Changes in Atmospheric Circulation
Published In
Global and Planetary Change
Document Type
Citation
Publication Date
3-1-2024
Abstract
The oxygen isotope compositions in atmospheric water including water vapor and precipitation have been widely used to trace moisture sources and to reconstruct past climates. However, the environmental controls of stable isotopes in atmospheric water depend on the time scales. Because of limited observations in arid Central Asia, factors controlling interannual variations in atmospheric water isotopes are still not clear. Using an isotope-enabled general climate model, we do not find at the annual scale the significant relationship between temperature and δ18O values during 1979–2020 that is usually observed at the monthly scale. Under a warming background, there is no significant enriching trend in water isotopes. We found a strong positive correlation between westerly (and southerly) water vapor flux and δ18O values on an interannual scale for the area between 35°N–50°N and 50°E–80°E in the upstream direction. High and low δ18O years are characterized by different atmospheric circulations of mid-latitude Westerlies, and do not always correspond to the warm and cold years respectively. When the prevailing Westerlies are enhanced, the Westerlies circulation may carry more water vapor from the lower latitudes, leading to higher δ18O values in Central Asia. The changes in Westerlies circulation are supported by the clustered backward trajectories during enriched and depleted years. The limited precipitation isotope observations also show similar findings as the simulations on an interannual scale. The interannual variations of stable isotopes in atmospheric water in arid Central Asia reflect the changes in the mid-latitude Westerlies circulation. This should be taken into account when interpreting oxygen isotope proxies of paleoclimate records.
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© 2024 Elsevier B.V. All rights reserved.
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DOI
10.1016/j.gloplacha.2024.104367
Persistent Identifier
https://archives.pdx.edu/ds/psu/41711
Citation Details
Wang, S., Yang, G., Bershaw, J., Liu, X., Yoshimura, K., Xiao, Y., & Zhang, M. (2024). Interannual variations in stable isotopes of atmospheric water in arid Central Asia due to changes in atmospheric circulation. Global and Planetary Change, 234, 104367.