Disentangling the impact of air-sea interaction and boundary layer cloud formation on stable water isotope signals in the warm sector of a Southern Ocean cyclone ...
Stable water isotopes in marine boundary layer water vapour are strongly influenced by the strength of air-sea fluxes. Air-sea fluxes in the extratropics are modulated by the large-scale atmospheric flow, for instance by the advection of warm and moist air masses in the warm sector of extratropical...
| Main Authors: | , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
ETH Zurich
2022
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.3929/ethz-b-000565383 http://hdl.handle.net/20.500.11850/565383 |
| Summary: | Stable water isotopes in marine boundary layer water vapour are strongly influenced by the strength of air-sea fluxes. Air-sea fluxes in the extratropics are modulated by the large-scale atmospheric flow, for instance by the advection of warm and moist air masses in the warm sector of extratropical cyclones. A distinct isotopic composition of the water vapour in the latter environment has been observed over the Southern Ocean during the 2016/2017 Antarctic Circumnavigation Expedition (ACE). Most prominently, the secondary isotope variable deuterium excess (d =delta H-2-8 center dot delta O-18) shows negative values in the cyclones' warm sector. In this study, three mechanisms are proposed and evaluated to explain these observed negative d values. We present three single-process air parcel models, which simulate the evolution of delta H-2, delta O-18, d and specific humidity in an air parcel induced by decreasing ocean evaporation, dew deposition and upstream cloud formation. Simulations with the ... : Atmospheric Chemistry and Physics, 22 (15) ... |
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