EGU21-3649
https://doi.org/10.5194/egusphere-egu21-3649
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Isotopic evidence for importance of atmospheric acidity on sulfate formation in the Mt. Everest region

Shohei Hattori1, Kun Wang2, Mang Lin3, Sakiko Ishino4, Becky Alexander5, Kazuki Kamezaki6, Naohiro Yoshida1, and Shichang Kang2
Shohei Hattori et al.
  • 1Tokyo Institute of Technology, School of Materials and Chemical Technology, Department of Chemical Science and Engineering, Kanagawa, Japan (hattori.s.ab@m.titech.ac.jp)
  • 2State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
  • 3State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, CAS, Guangzhou 510640, China
  • 4National Institute of Polar Research, Research Organization of Information and Systems, Tokyo 190-8518, Japan
  • 5Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA
  • 6Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo, 102-8554, Japan

Oxygen-17 anomaly (Δ17O) has been used as a probe to constrain the relative importance of different pathways leading to sulfate formation. Here, we report the Δ17O values in atmospheric sulfate collected at a remote site in the Mt. Everest region to decipher the possible formation mechanisms of sulfate in such a pristine environment. The Δ17O in non-dust sulfate show higher values than most existing data in modern atmospheric sulfate. The seasonality of Δ17O in non-dust sulfate exhibits high values in the pre-monsoon and low values in the monsoon, opposite to the seasonality in Δ17O for both sulfate and nitrate (i.e., minima in warm season and maxima in cold season) observed from diverse geographic sites. This high Δ17O in non-dust sulfate found in this region clearly indicates the important role of the S(IV) + O3 pathway in atmospheric sulfate formation promoted by high cloud water pH conditions. In turn, this study highlights observational evidence that atmospheric acidity plays an important role in controlling sulfate formation pathways particularly for dust-rich environments.

How to cite: Hattori, S., Wang, K., Lin, M., Ishino, S., Alexander, B., Kamezaki, K., Yoshida, N., and Kang, S.: Isotopic evidence for importance of atmospheric acidity on sulfate formation in the Mt. Everest region, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3649, https://doi.org/10.5194/egusphere-egu21-3649, 2021.

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