Meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the Atlantic and Southern Ocean
Stable water isotopologues (SWIs) are useful tracers of moist diabatic processes in the atmospheric water cycle. They provide a framework to analyse moist processes on a range of timescales from large-scale moisture transport to cloud formation, precipitation and small-scale turbulent mixing. Laser...
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Gottingen, COPERNICUS GESELLSCHAFT MBH
2020
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Online Access: | https://doi.org/10.5194/acp-20-5811-2020 https://infoscience.epfl.ch/record/277915/files/acp-20-5811-2020.pdf http://infoscience.epfl.ch/record/277915 |
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ftinfoscience:oai:infoscience.epfl.ch:277915 2023-05-15T13:45:36+02:00 Meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the Atlantic and Southern Ocean Thurnherr, Iris Kozachek, Anna Graf, Pascal Weng, Yongbiao Bolshiyanov, Dimitri Landwehr, Sebastian Pfahl, Stephan Schmale, Julia Sodemann, Harald Steen-Larsen, Hans Christian Toffoli, Alessandro Wernli, Heini Aemisegger, Franziska 2020-06-07T00:20:55Z https://doi.org/10.5194/acp-20-5811-2020 https://infoscience.epfl.ch/record/277915/files/acp-20-5811-2020.pdf http://infoscience.epfl.ch/record/277915 unknown Gottingen, COPERNICUS GESELLSCHAFT MBH isi:000535264700001 doi:10.5194/acp-20-5811-2020 https://infoscience.epfl.ch/record/277915/files/acp-20-5811-2020.pdf http://infoscience.epfl.ch/record/277915 http://infoscience.epfl.ch/record/277915 Text 2020 ftinfoscience https://doi.org/10.5194/acp-20-5811-2020 2023-02-13T23:00:16Z Stable water isotopologues (SWIs) are useful tracers of moist diabatic processes in the atmospheric water cycle. They provide a framework to analyse moist processes on a range of timescales from large-scale moisture transport to cloud formation, precipitation and small-scale turbulent mixing. Laser spectrometric measurements on research vessels produce high-resolution time series of the variability of the water vapour isotopic composition in the marine boundary layer. In this study, we present a 5-month continuous time series of such ship-based measurements of delta H-2 and delta O-18 from the Antarctic Circumnavigation Expedition (ACE) in the Atlantic and the Southern Ocean in the time period from November 2016 to April 2017. We analyse the drivers of meridional SWI variations in the marine boundary layer across diverse climate zones in the Atlantic and Southern Ocean using Lagrangian moisture source diagnostics and relate vertical SWI differences to near-surface wind speed and ocean surface state. The median values of delta O-18, delta H-2 and deuterium excess during ACE decrease continuously from low to high latitudes. These meridional SWI distributions reflect climatic conditions at the measurement and moisture source locations, such as air temperature, specific humidity and relative humidity with respect to sea surface temperature. The SWI variability at a given latitude is highest in the extratropics and polar regions with decreasing values equatorwards. This meridional distribution of SWI variability is explained by the variability in moisture source locations and its associated environmental conditions as well as transport processes. The westward-located moisture sources of water vapour in the extratropics are highly variable in extent and latitude due to the frequent passage of cyclones and thus widen the range of encountered SWI values in the marine boundary layer. Moisture loss during transport further contributes to the high SWI variability in the extratropics. In the subtropics and tropics, ... Text Antarc* Antarctic Southern Ocean EPFL Infoscience (Ecole Polytechnique Fédérale Lausanne) Antarctic Southern Ocean The Antarctic Atmospheric Chemistry and Physics 20 9 5811 5835 |
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EPFL Infoscience (Ecole Polytechnique Fédérale Lausanne) |
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ftinfoscience |
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unknown |
description |
Stable water isotopologues (SWIs) are useful tracers of moist diabatic processes in the atmospheric water cycle. They provide a framework to analyse moist processes on a range of timescales from large-scale moisture transport to cloud formation, precipitation and small-scale turbulent mixing. Laser spectrometric measurements on research vessels produce high-resolution time series of the variability of the water vapour isotopic composition in the marine boundary layer. In this study, we present a 5-month continuous time series of such ship-based measurements of delta H-2 and delta O-18 from the Antarctic Circumnavigation Expedition (ACE) in the Atlantic and the Southern Ocean in the time period from November 2016 to April 2017. We analyse the drivers of meridional SWI variations in the marine boundary layer across diverse climate zones in the Atlantic and Southern Ocean using Lagrangian moisture source diagnostics and relate vertical SWI differences to near-surface wind speed and ocean surface state. The median values of delta O-18, delta H-2 and deuterium excess during ACE decrease continuously from low to high latitudes. These meridional SWI distributions reflect climatic conditions at the measurement and moisture source locations, such as air temperature, specific humidity and relative humidity with respect to sea surface temperature. The SWI variability at a given latitude is highest in the extratropics and polar regions with decreasing values equatorwards. This meridional distribution of SWI variability is explained by the variability in moisture source locations and its associated environmental conditions as well as transport processes. The westward-located moisture sources of water vapour in the extratropics are highly variable in extent and latitude due to the frequent passage of cyclones and thus widen the range of encountered SWI values in the marine boundary layer. Moisture loss during transport further contributes to the high SWI variability in the extratropics. In the subtropics and tropics, ... |
format |
Text |
author |
Thurnherr, Iris Kozachek, Anna Graf, Pascal Weng, Yongbiao Bolshiyanov, Dimitri Landwehr, Sebastian Pfahl, Stephan Schmale, Julia Sodemann, Harald Steen-Larsen, Hans Christian Toffoli, Alessandro Wernli, Heini Aemisegger, Franziska |
spellingShingle |
Thurnherr, Iris Kozachek, Anna Graf, Pascal Weng, Yongbiao Bolshiyanov, Dimitri Landwehr, Sebastian Pfahl, Stephan Schmale, Julia Sodemann, Harald Steen-Larsen, Hans Christian Toffoli, Alessandro Wernli, Heini Aemisegger, Franziska Meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the Atlantic and Southern Ocean |
author_facet |
Thurnherr, Iris Kozachek, Anna Graf, Pascal Weng, Yongbiao Bolshiyanov, Dimitri Landwehr, Sebastian Pfahl, Stephan Schmale, Julia Sodemann, Harald Steen-Larsen, Hans Christian Toffoli, Alessandro Wernli, Heini Aemisegger, Franziska |
author_sort |
Thurnherr, Iris |
title |
Meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the Atlantic and Southern Ocean |
title_short |
Meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the Atlantic and Southern Ocean |
title_full |
Meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the Atlantic and Southern Ocean |
title_fullStr |
Meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the Atlantic and Southern Ocean |
title_full_unstemmed |
Meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the Atlantic and Southern Ocean |
title_sort |
meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the atlantic and southern ocean |
publisher |
Gottingen, COPERNICUS GESELLSCHAFT MBH |
publishDate |
2020 |
url |
https://doi.org/10.5194/acp-20-5811-2020 https://infoscience.epfl.ch/record/277915/files/acp-20-5811-2020.pdf http://infoscience.epfl.ch/record/277915 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
http://infoscience.epfl.ch/record/277915 |
op_relation |
isi:000535264700001 doi:10.5194/acp-20-5811-2020 https://infoscience.epfl.ch/record/277915/files/acp-20-5811-2020.pdf http://infoscience.epfl.ch/record/277915 |
op_doi |
https://doi.org/10.5194/acp-20-5811-2020 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
20 |
container_issue |
9 |
container_start_page |
5811 |
op_container_end_page |
5835 |
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1766228457611591680 |