Physical Sciences Division
Published October 16, 2023 | Version v1
Journal article Open

The dehydration carousel of stratospheric water vapor in the Asian summer monsoon anticyclone

Creators

  • 1. Forschungszentrum Jülich
  • 2. Laboratoire Atmospheres
  • 3. University of Chicago
  • 4. National Research Council
  • 5. National Institute of Optics

Description

During the StratoClim Geophysica campaign, air with total water mixing ratios up to 200 ppmv and ozone up to 250 ppbv was observed within the Asian summer monsoon anticyclone up to 1.7 km above the local cold-point tropopause (CPT). To investigate the temporal evolution of enhanced water vapor being transported into the stratosphere, we conduct forward trajectory simulations using both a microphysical and an idealized freeze-drying model. The models are initialized at the measurement locations and the evolution of water vapor and ice is compared with satellite observations of MLS and CALIPSO. Our results show that these extremely high water vapor values observed above the CPT are very likely to undergo significant further freeze-drying due to experiencing extremely cold temperatures while circulating in the anticyclonic "dehydration carousel". We also use the Lagrangian dry point (LDP) of the merged back-and-forward trajectories to reconstruct the water vapor fields. The results show that the extremely high water vapor mixed with the stratospheric air has a negligible impact on the overall water vapor budget. The LDP mixing ratios are a better proxy for the large-scale water vapor distributions in the stratosphere during this period.

Data availability

The trajectory module (TRAJ) is a part of CLaMS-2.0/MESSy code based on MESSy version 2.54 and accessible at Forschungszentrum Jülich (McKenna et al., 2002; https://gitlab.dkrz.de/MESSy, login required). The usage of MESSy and access to the source code is licensed to all affiliates of institutions that are members of the MESSy Consortium. Institutions can become a member of the MESSy Consortium by signing the MESSy Memorandum of Understanding. More information can be found on the MESSy Consortium Website (http://www.messy-interface.org, Jöckel and the MESSy Consortium, 2023). ERA5 data are available at https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5 (login required, Hersbach et al., 2020). The StratoClim data is hosted within the HALO database at https://halo-db.pa.op.dlr.de/mission/101 (DLR, 2023). For more detailed model data, please contact the authors.

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acp-23-12935-2023.pdf

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Additional details

Identifiers

DOI
10.5194/acp-23-12935-2023
Other
oai:uchicago.tind.io:13918

Funding

Deutsche Forschungsgemeinschaft
428312742
European Commission
603557
Forschungszentrum Jülich

UChicago Information

Division(s)
Physical Sciences Division
Department(s)
Geophysical Sciences