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GPS - Zenith Total Delay assimilation in different resolution simulations of a heavy precipitation event over southern France / Alberto Caldas-Álvarez in Advances in Science and Research, vol 14 (2017)    

Public [article]  inAdvances in Science and Research > vol 14 (2017) . - pp 157 - 162 Titre : GPS - Zenith Total Delay assimilation in different resolution simulations of a heavy precipitation event over southern France Type de document : Article/Communication Auteurs : Alberto Caldas-Álvarez, Auteur ; Samiro Khodayar, Auteur ; Olivier Bock , Auteur Congrès : EMS 2016, 16th European Meteorological Society annual meeting (12 - 16 Septembre 2016; Trieste, Italie), Commanditaire Année de publication : 2017 Projets : HyMeX / Article en page(s) : pp 157 - 162 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes descripteurs IGN] distribution spatiale [Termes descripteurs IGN] humidité de l'air [Termes descripteurs IGN] précipitation [Termes descripteurs IGN] retard troposphérique zénithal [Termes descripteurs IGN] teneur intégré en vapeur d'eau Mots-clés libres : ANR-11-BS56-0005 et ANR-12-SENV-001 Résumé : (auteur) The aim of this study is to investigate the different pathways of the interaction between an improved atmospheric moisture distribution by Data Assimilation (DA) of Global Positioning System Zenith Total Delays (GPS-ZTD) on the simulation of a selected Heavy Precipitation Event (HPE) across different model horizontal resolutions (7 km, 2.8 km and 500 m). The initiation and evolution of deep moist convection and heavy precipitation taking place on the 24 September 2012, which had a dedicated Intensive Observation Period (IOP6) during the Hydrological cycle in the Mediterranean eXperiment (HyMeX) Special Observation period 1, are analysed. The results show an improvement in the representation of the Integrated Water Vapour (IWV) spatial distribution and temporal evolution when the data assimilation is applied as well as through the refinement of the model grids. However, important discrepancies between the simulated and the observed vertical profiles of humidity still remain after the DA, thus affecting the representation of convection and heavy precipitation. For the presented case study, the model simulations exhibited a wet bias. The assimilation entailed a drying of the low to middle troposphere over the study region during the 6 h prior to the storm initiation for every horizontal resolution. This reduced the instability present at the moment of storm initiation, weakening in return the intensity of convection and the number of cells triggered. The improvement observed in the atmospheric moisture content and distribution was not followed by an improved precipitation representation closer to observations. This highlights the relevance of correctly distributing the assimilated IWV in the vertical direction in the models. Numéro de notice : A2017-862 Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.5194/asr-14-157-2017 date de publication en ligne : 13/06/2017 En ligne : https://doi.org/10.5194/asr-14-157-2017 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89849 [article]

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The variability of water vapour and pre-convective conditions over the mountainous island of Corsica / Bianca Adler in Quarterly Journal of the Royal Meteorological Society, vol 142 n° S1 (August 2016)  

Public [article]  inQuarterly Journal of the Royal Meteorological Society > vol 142 n° S1 (August 2016) . - pp 335 - 346 Titre : The variability of water vapour and pre-convective conditions over the mountainous island of Corsica Type de document : Article/Communication Auteurs : Bianca Adler, Auteur ; Norbert Kalthoff, Auteur ; Martin Kohler, Auteur ; Jan Handwerker, Auteur ; Andreas Wieser, Auteur ; Ulrich Corsmeier, Auteur ; Christoph Kottmeier, Auteur ; Dominique Lambert, Auteur ; Olivier Bock , Auteur Année de publication : 2016 Projets : HyMeX / Article en page(s) : pp 335 - 346 Note générale : biblographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes descripteurs IGN] circulation atmosphérique [Termes descripteurs IGN] convection [Termes descripteurs IGN] coordonnées GPS [Termes descripteurs IGN] Corse [Termes descripteurs IGN] couche atmosphérique [Termes descripteurs IGN] données météorologiques [Termes descripteurs IGN] teneur intégré en vapeur d'eau Résumé : (auteur) Comprehensive measurements were carried out on the mountainous island of Corsica during the Hydrological cycle in the Mediterranean Experiment (HyMeX) field campaign in 2012. Using data from an operational GPS network, radiosondes and microwave radiometers, we studied the spatio-temporal variability of integrated water vapour (IWV) and convection-related parameters in the pre-convective environment over the island. The following spatial differences in the IWV evolution occurred frequently. In the interior of the island the IWV strongly increased around noon, while on the upstream coast only small variations were observed. We showed that a transport of water vapour with thermally driven circulations and the formation of elevated humidity layers due to advective venting caused the diurnal IWV variation over and downstream of the mountains. Spatial inhomogeneities in the pre-convective atmospheric conditions evolved and the knowledge of these turned out to be crucial to understanding the timing and location of isolated deep convection over the island. Numéro de notice : A2016-937 Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/qj.2545 date de publication en ligne : 04/03/2015 En ligne : http://dx.doi.org/10.1002/qj.2545 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83290 [article]