Water vapour measurements from a ground-based Raman lidar and an airborne differential absorption lidar, complemented by high resolution numerical simulations from two mesoscale models (AROME-WMED and Meso-NH), are considered to investigate three transition events from Mistral/Tramontane to southerly marine flow taking place in the Montpellier region (Southern France) in the time frame September-October 2012, during the Hydrological Cycle in the Mediterranean Experiment Special Observation Period 1. Low-level wind reversals associated with these transitions are found to have a strong impact on water vapour transport, leading to a large variability of the water vapour vertical and horizontal distributions. Water vapour mixing ratio within the boundary layer is found to vary from typical values in the range 4-8 g kg-1 during the northerly Mistral/Tramontane flows to values in the range 8-15 g kg-1 during the southerly marine flows. The increase/decrease in water vapour mixing ratio within the boundary layer may be abrupt and marked during these transition periods, with values increasing-decreasing by a factor of 2 to 4 within 1 hour. The high spatial and temporal resolutions of the lidar data allow monitoring the time evolution of the water vapour field during these transitions from predominantly northerly Mistral/Tramontane flow to a predominantly southerly flow, permitting to identify the quite sharp separation between these flows, which is also satisfactorily well captured by the mesoscale models. Water vapour measurements from the ground-based lidar are complemented by particle backscatter measurements from the same system, which allow also revealing the significant variability in the aerosol and cloud fields associated with these transition events.

The radiative impact of desert dust on orographic rain in the Cévennes-Vivarais area: A case study from HyMeX / Flamant, C; Chaboureau, J. P.; Chazette, P.; Di Girolamo, P.; Bourrianne, T.; Totems, J.; Cacciani, Marco. - In: ATMOSPHERIC CHEMISTRY AND PHYSICS. - ISSN 1680-7316. - ELETTRONICO. - 15:21(2015), pp. 12231-12249. [10.5194/acp-15-12231-2015]

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

CACCIANI, Marco
2015

Abstract

Water vapour measurements from a ground-based Raman lidar and an airborne differential absorption lidar, complemented by high resolution numerical simulations from two mesoscale models (AROME-WMED and Meso-NH), are considered to investigate three transition events from Mistral/Tramontane to southerly marine flow taking place in the Montpellier region (Southern France) in the time frame September-October 2012, during the Hydrological Cycle in the Mediterranean Experiment Special Observation Period 1. Low-level wind reversals associated with these transitions are found to have a strong impact on water vapour transport, leading to a large variability of the water vapour vertical and horizontal distributions. Water vapour mixing ratio within the boundary layer is found to vary from typical values in the range 4-8 g kg-1 during the northerly Mistral/Tramontane flows to values in the range 8-15 g kg-1 during the southerly marine flows. The increase/decrease in water vapour mixing ratio within the boundary layer may be abrupt and marked during these transition periods, with values increasing-decreasing by a factor of 2 to 4 within 1 hour. The high spatial and temporal resolutions of the lidar data allow monitoring the time evolution of the water vapour field during these transitions from predominantly northerly Mistral/Tramontane flow to a predominantly southerly flow, permitting to identify the quite sharp separation between these flows, which is also satisfactorily well captured by the mesoscale models. Water vapour measurements from the ground-based lidar are complemented by particle backscatter measurements from the same system, which allow also revealing the significant variability in the aerosol and cloud fields associated with these transition events.
File allegati a questo prodotto
File Dimensione Formato  
Flamant_Radiative_2015.pdf

accesso aperto

Note: Articolo principale
Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Creative commons
Dimensione 3.58 MB
Formato Adobe PDF
3.58 MB Adobe PDF Visualizza/Apri PDF

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/863430
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 4
  • ???jsp.display-item.citation.isi??? 4
social impact