EGU23-14405, updated on 06 Nov 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Microphysical Modeling of Water Isotopic Composition in the Asian Summer Monsoon

Benjamin Clouser1, Carly KleinStern1, Sergey Khaykin2, Clare Singer1, Laszlo Sarkozy1, Silvia Viciani3, Giovanni Bianchini3, Francesco D'Amato3, Alexey Lykov4, Alexey Ulanovsky5, Frank WIenhold6, Bernard Legras7, Cameron Homeyer8, Troy Thornberry9, and Elisabeth Moyer1
Benjamin Clouser et al.
  • 1University of Chicago, Chicago, United States of America (
  • 2Laboratoire Atmosphères, Observations Spatiales (LATMOS), CNRS/INSU, Sorbonne Université, Guyancourt, France
  • 3Consiglio Nazionale delle Ricerche – Istituto Nazionale di Ottica (CNR-INO), Area CNR, Via Madonna del Piano 10, 50019 Sesto F. no (FI), Italy
  • 4Central Aerological Observatory of RosHydroMet, Dolgoprudny, Russia
  • 5Central Aerological Observatory (CAO), Moscow, Russia
  • 6Institute for Atmospheric and Climate Science (IAC), Swiss Federal Institute of Technology (ETH), Zürich, Switzerland
  • 7Laboratoire de Météorologie Dynamique, IPSL, CNRS, ENS-PSL/Sorbonne Univ., Paris, France
  • 8School of Meteorology, University of Oklahoma, Norman, OK, USA
  • 9NOAA Chemical Sciences Laboratory (CSL), Boulder, USA

The summertime Asian Monsoon (AM) is the single most important contributor to water vapor in the UTLS and overworld stratosphere. Much of that water comes from sublimating ice, but the life cycle of the condensate lofted by overshooting convection is not well understood. We report here on insights into that life cycle derived from the first in-situ measurements of water vapor isotopic composition over the Asian Monsoon. The Chicago Water Isotope Spectrometer (ChiWIS) flew on high-altitude aircraft in the monsoon center during the StratoClim (2017) campaign out of Nepal, and in monsoon outflow during ACCLIP (2022) out of South Korea. Both campaigns sampled a broad range of convective and post-convective conditions, letting us trace how convective ice sublimates, reforms, and leaves behind characteristic isotopic signatures. We use the Bin Resolved Isotopic Microphysical Model (BRIMM), along with TRACZILLA backtrajectories and convective interactions derived from cloud-top products, to follow the evolving isotopic composition along flight paths in both campaigns. Results support the wide diversity of isotopic enhancements seen in both campaigns and show how temperature cycles downstream of convective events progressively modify environmental isotopic compositions.

How to cite: Clouser, B., KleinStern, C., Khaykin, S., Singer, C., Sarkozy, L., Viciani, S., Bianchini, G., D'Amato, F., Lykov, A., Ulanovsky, A., WIenhold, F., Legras, B., Homeyer, C., Thornberry, T., and Moyer, E.: Microphysical Modeling of Water Isotopic Composition in the Asian Summer Monsoon, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14405,, 2023.