EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

In-situ measurements of the HDO/H2O Isotopic ratio in the Asian Summer Monsoon trace strong convective activity

Benjamin Clouser1, Clare Singer2, Sergey Khaykin3, Martina Krämer4, Alexey Lykov5, Sylvia Bucci6, Bernard Legras6, Stephan Borrmann7, Francesco Cairo8, Valentin Mitev9, Renaud Matthey10, Fabrizio Ravegnani8, Christian Rolf4, Alexey Ulanovsky11, Silvia Viciani12, Francesco D'Amato12, C Michael Volk13, Vladimir Yushkov11, Fred Stroh4, and Elisabeth Moyer1
Benjamin Clouser et al.
  • 1University of Chicago, Chicago, United States of America (
  • 2California Institute of Technology, Pasadena, CA, USA
  • 3LATMOS/IPSL, UVSQ, Sorbonne Université, CNRS, Guyancourt, France
  • 4Forschungszentrum Jülich, Institut für Energie und Klimaforschung (IEK-7), Germany
  • 5Central Aerological Observatory of RosHydroMet, Dolgoprudny, Russian Federation
  • 6Laboratoire de Météorologie Dynamique, ENS, CNRS, Paris, France
  • 7Max Planck Institute for Chemistry, Mainz, Germany
  • 8Institute for Atmospheric Sciences and Climate, ISAC-CNR, Rome, Italy
  • 9Centre Suisse d’Electronique et de Microtechnique Neuchâtel, Switzerland
  • 10LTF, University of Neuchâtel, Neuchâtel, Switzerland
  • 11Central Aerological Observatory of RosHydroMet, Moscow, Russian Federation
  • 12CNR-INO, Firenze, Italy
  • 13Institute for Atmospheric and Environmental Research, University of Wuppertal, Wuppertal, Germany

In-situ measurements of the HDO/H2O isotopic ratio from the Chicago Water Isotope Spectrometer (ChiWIS) during the 2017 StratoClim campaign help diagnose convective processes in the Asian Monsoon. Isotopic measurements show enormous diversity in isotopic composition, likely reflecting degree of recent convective influence. Eight flights in July—August sampled a wide range of convective influence at near-tropopause altitudes, with timescales of minutes to weeks, and mean isotopic compositions from -700 per mil in recent convective outflow to -350 per mil in more aged air that is at least several days from last convective influence. Above the tropopause, we use isotopic composition to understand the fate of convective remnants. Isotopic measurements suggest much in-situ cirrus measured during  StratoClim campaign is actually secondary cirrus which has reformed in an area of prior convective moistening. These flights allow detailed comparison between North American and Asian monsoons, and we compare StratoClim results to both satellite and in-situ measurements in other monsoon and tropical locations. Finally, we discuss prospects for detection and interpretation of convective remnants during the in the 2021/2022 ACCLIP campaign.

How to cite: Clouser, B., Singer, C., Khaykin, S., Krämer, M., Lykov, A., Bucci, S., Legras, B., Borrmann, S., Cairo, F., Mitev, V., Matthey, R., Ravegnani, F., Rolf, C., Ulanovsky, A., Viciani, S., D'Amato, F., Volk, C. M., Yushkov, V., Stroh, F., and Moyer, E.: In-situ measurements of the HDO/H2O Isotopic ratio in the Asian Summer Monsoon trace strong convective activity, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14171,, 2021.

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