Contrasting stable water isotope signals from convective and large-scale precipitation phases of a heavy precipitation event in southern Italy during HyMeX IOP 13: A modelling perspective
The dynamical context and moisture transport pathways embedded in large-scale flow and associated with a heavy precipitation event (HPE) in southern Italy (SI) are investigated with the help of stable water isotopes (SWIs) based on a purely numerical framework. The event occurred during the Intensiv...
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ftethz:oai:www.research-collection.ethz.ch:20.500.11850/347653 2023-05-15T17:36:48+02:00 Contrasting stable water isotope signals from convective and large-scale precipitation phases of a heavy precipitation event in southern Italy during HyMeX IOP 13: A modelling perspective Lee, Keun-Ok Aemisegger, Franziska Pfahl, Stephan Flamant, Cyrille Lacour, Jean-Lionel Chaboureau, Jean-Pierre 2019 application/application/pdf https://hdl.handle.net/20.500.11850/347653 https://doi.org/10.3929/ethz-b-000347653 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/acp-19-7487-2019 info:eu-repo/semantics/altIdentifier/wos/000470732300005 http://hdl.handle.net/20.500.11850/347653 doi:10.3929/ethz-b-000347653 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International CC-BY Atmospheric Chemistry and Physics, 19 (11) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2019 ftethz https://doi.org/20.500.11850/347653 https://doi.org/10.3929/ethz-b-000347653 https://doi.org/10.5194/acp-19-7487-2019 2023-02-13T00:47:56Z The dynamical context and moisture transport pathways embedded in large-scale flow and associated with a heavy precipitation event (HPE) in southern Italy (SI) are investigated with the help of stable water isotopes (SWIs) based on a purely numerical framework. The event occurred during the Intensive Observation Period (IOP) 13 of the field campaign of the Hydrological Cycle in the Mediterranean Experiment (HyMeX) on 15 and 16 October 2012, and SI experienced intense rainfall of 62.4 mm over 27 h with two precipitation phases during this event. The first one (P1) was induced by convective precipitation ahead of a cold front, while the second one (P2) was mainly associated with precipitation induced by large-scale uplift. The moisture transport and processes responsible for the HPE are analysed using a simulation with the isotope-enabled regional numerical model COSMOiso. The simulation at a horizontal grid spacing of about 7 km over a large domain (about 4300 km ×3500 km) allows the isotopes signal to be distinguished due to local processes or large-scale advection. Backward trajectory analyses based on this simulation show that the air parcels arriving in SI during P1 originate from the North Atlantic and descend within an upper-level trough over the north-western Mediterranean. The descending air parcels reach elevations below 1 km over the sea and bring dry and isotopically depleted air (median δ18O ≤−25 ‰, water vapour mixing ratio q≤2 g kg−1) close to the surface, which induces strong surface evaporation. These air parcels are rapidly enriched in SWIs (δ18O ≥−14 ‰) and moistened (q≥8 g kg−1) over the Tyrrhenian Sea by taking up moisture from surface evaporation and potentially from evaporation of frontal precipitation. Thereafter, the SWI-enriched low-level air masses arriving upstream of SI are convectively pumped to higher altitudes, and the SWI-depleted moisture from higher levels is transported towards the surface within the downdrafts ahead of the cold front over SI, producing a large amount of ... Article in Journal/Newspaper North Atlantic ETH Zürich Research Collection |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
description |
The dynamical context and moisture transport pathways embedded in large-scale flow and associated with a heavy precipitation event (HPE) in southern Italy (SI) are investigated with the help of stable water isotopes (SWIs) based on a purely numerical framework. The event occurred during the Intensive Observation Period (IOP) 13 of the field campaign of the Hydrological Cycle in the Mediterranean Experiment (HyMeX) on 15 and 16 October 2012, and SI experienced intense rainfall of 62.4 mm over 27 h with two precipitation phases during this event. The first one (P1) was induced by convective precipitation ahead of a cold front, while the second one (P2) was mainly associated with precipitation induced by large-scale uplift. The moisture transport and processes responsible for the HPE are analysed using a simulation with the isotope-enabled regional numerical model COSMOiso. The simulation at a horizontal grid spacing of about 7 km over a large domain (about 4300 km ×3500 km) allows the isotopes signal to be distinguished due to local processes or large-scale advection. Backward trajectory analyses based on this simulation show that the air parcels arriving in SI during P1 originate from the North Atlantic and descend within an upper-level trough over the north-western Mediterranean. The descending air parcels reach elevations below 1 km over the sea and bring dry and isotopically depleted air (median δ18O ≤−25 ‰, water vapour mixing ratio q≤2 g kg−1) close to the surface, which induces strong surface evaporation. These air parcels are rapidly enriched in SWIs (δ18O ≥−14 ‰) and moistened (q≥8 g kg−1) over the Tyrrhenian Sea by taking up moisture from surface evaporation and potentially from evaporation of frontal precipitation. Thereafter, the SWI-enriched low-level air masses arriving upstream of SI are convectively pumped to higher altitudes, and the SWI-depleted moisture from higher levels is transported towards the surface within the downdrafts ahead of the cold front over SI, producing a large amount of ... |
format |
Article in Journal/Newspaper |
author |
Lee, Keun-Ok Aemisegger, Franziska Pfahl, Stephan Flamant, Cyrille Lacour, Jean-Lionel Chaboureau, Jean-Pierre |
spellingShingle |
Lee, Keun-Ok Aemisegger, Franziska Pfahl, Stephan Flamant, Cyrille Lacour, Jean-Lionel Chaboureau, Jean-Pierre Contrasting stable water isotope signals from convective and large-scale precipitation phases of a heavy precipitation event in southern Italy during HyMeX IOP 13: A modelling perspective |
author_facet |
Lee, Keun-Ok Aemisegger, Franziska Pfahl, Stephan Flamant, Cyrille Lacour, Jean-Lionel Chaboureau, Jean-Pierre |
author_sort |
Lee, Keun-Ok |
title |
Contrasting stable water isotope signals from convective and large-scale precipitation phases of a heavy precipitation event in southern Italy during HyMeX IOP 13: A modelling perspective |
title_short |
Contrasting stable water isotope signals from convective and large-scale precipitation phases of a heavy precipitation event in southern Italy during HyMeX IOP 13: A modelling perspective |
title_full |
Contrasting stable water isotope signals from convective and large-scale precipitation phases of a heavy precipitation event in southern Italy during HyMeX IOP 13: A modelling perspective |
title_fullStr |
Contrasting stable water isotope signals from convective and large-scale precipitation phases of a heavy precipitation event in southern Italy during HyMeX IOP 13: A modelling perspective |
title_full_unstemmed |
Contrasting stable water isotope signals from convective and large-scale precipitation phases of a heavy precipitation event in southern Italy during HyMeX IOP 13: A modelling perspective |
title_sort |
contrasting stable water isotope signals from convective and large-scale precipitation phases of a heavy precipitation event in southern italy during hymex iop 13: a modelling perspective |
publisher |
Copernicus |
publishDate |
2019 |
url |
https://hdl.handle.net/20.500.11850/347653 https://doi.org/10.3929/ethz-b-000347653 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Atmospheric Chemistry and Physics, 19 (11) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/acp-19-7487-2019 info:eu-repo/semantics/altIdentifier/wos/000470732300005 http://hdl.handle.net/20.500.11850/347653 doi:10.3929/ethz-b-000347653 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/20.500.11850/347653 https://doi.org/10.3929/ethz-b-000347653 https://doi.org/10.5194/acp-19-7487-2019 |
_version_ |
1766136407175200768 |