The radiative impact of desert dust on orographic rain in the Cévennes–Vivarais area: a case study from HyMeX

Cyrille Flamant 1 Jean-Pierre Chaboureau 2 Patrick Chazette 3 Paolo Di Girolamo 4 Tierry Bourrianne 5 Julien Totems 3 Marco Cacciani 6
1 TROPO - LATMOS
LATMOS - Laboratoire Atmosphères, Milieux, Observations Spatiales
2 LA - Laboratoire d'aérologie - LA
3 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
4 Difa - Dipartimento di Ingegneria e Fisica dell'Ambiente [Potenza]
5 CNRM-GAME - Groupe d'étude de l'atmosphère météorologique
6 Dipartimento di Fisica [Roma La Sapienza]
Abstract : The study is focused on Intensive Observation Period (IOP) 14 of the Hydrology Cycle in the Mediterranean Experiment first Special Observing Period (HyMeX SOP 1) that took place from 17 to 19 October and was dedicated to the study of orographic rain in the Cevennes Vivarais (CV) target area. During this IOP a dense dust plume originating from North Africa (Maghreb and Sahara) was observed to be transported over the Balearic Islands towards the south of France. The plume was characterized by an aerosol optical depth between 0.2 and 0.8 at 550 nm, highly variable in time and space over the Western Mediterranean basin. The impact of this dust plume, the biggest event observed during the 2 month long HyMeX SOP 1, on the precipitation over the CV area has been analyzed using high resolution simulations from the convection permitting mesoscale model Meso-NH validated against measurements obtained from numerous instruments deployed specifically during SOP 1 (ground-based/airborne water vapor and aerosol lidars, airborne microphysics probes) as well as space-borne aerosol products. The 4 day simulation reproduced realistically the temporal and spatial variability (incl. vertical distribution) of the dust. The dust radiative impact led to an average 0.6 K heating at the altitude of the dust layer in the CV area (and up to +3 K locally) and an average 100 J kg-1 increase of most unstable convective available potential energy (and up to +900 J kg-1 locally) with respect to a simulation without prescribed dust aerosols. The rainfall amounts and location were only marginally affected by the dust radiative effect, even after 4 days of simulation. The transient nature of this radiative effect in dynamical environments such as those found in the vicinity of heavy precipitation events in the Mediterranean is not sufficient to impact 24 h accumulated rainfall in the dusty simulation.
Document type :
Journal articles
Complete list of metadatas

Cited literature [53 references]  Display  Hide  Download
https://hal-insu.archives-ouvertes.fr/insu-01185672
Contributor : Catherine Cardon <>
Submitted on : Wednesday, November 4, 2015 - 2:23:36 PM
Last modification on : Thursday, May 16, 2019 - 1:14:01 PM
Long-term archiving on : Friday, February 5, 2016 - 11:28:03 AM

File

acp-15-12231-2015.pdf
Publisher files allowed on an open archive

Identifiers

Collections

METEO | UPMC | UVSQ | INSU | LATMOS | CEA | OMP-LA | OMP | CEA-UPSAY | LSCE | UNIV-PARIS-SACLAY | CEA-DRF | SORBONNE-UNIVERSITE | UNIV-TLSE3 | SU-SCIENCES

Citation

Cyrille Flamant, Jean-Pierre Chaboureau, Patrick Chazette, Paolo Di Girolamo, Tierry Bourrianne, et al.. The radiative impact of desert dust on orographic rain in the Cévennes–Vivarais area: a case study from HyMeX. Atmospheric Chemistry and Physics, European Geosciences Union, 2015, 15 (21), pp.12231-12249. ⟨10.5194/acp-15-12231-2015⟩. ⟨insu-01185672⟩

Export

BibTeX TEI DC DCterms EndNote

Share

Metrics

Record views

679

Files downloads

132

Contact

support.ccsd.cnrs.fr
hal.support@ccsd.cnrs.fr
Logo CCSD