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Precipitation frequency in MED and EURO-CORDEX ensembles from 0.44° to convective permitting resolution: Impact of model resolution and convection representation / Minh Ha-Truong (2022)  

Public Titre : Precipitation frequency in MED and EURO-CORDEX ensembles from 0.44° to convective permitting resolution: Impact of model resolution and convection representation Type de document : Article/Communication Auteurs : Minh Ha-Truong, Auteur ; Sophie Bastin, Auteur ; Philippe Drobinski, Auteur ; Lluis Fita, Auteur ; Marjolaine Chiriaco, Auteur ; Jan Polcher, Auteur ; Olivier Bock , Auteur ; et al., Auteur Editeur : Research Square Année de publication : 2022 Importance : 1 p. Format : 21 x 30 cm Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] bassin méditerranéen [Termes IGN] convection [Termes IGN] données météorologiques [Termes IGN] Europe (géographie politique) [Termes IGN] modèle atmosphérique [Termes IGN] orographie [Termes IGN] précipitation [Termes IGN] teneur intégrée en vapeur d'eau Résumé : (auteur) Recent studies using convection-permitting (CP) climate simulations have demonstrated a step-change in the representation of heavy rainfall and rainfall characteristics (frequency-intensity) compared to coarser resolution Global and Regional Climate models. The goal of this study is to better understand what explains the weaker frequency of precipitation in the CP ensemble by assessing the triggering process of precipitation in the different ensembles of regional climate simulations available over Europe. We focus on the statistical relationship between tropospheric temperature, humidity and precipitation to understand how the frequency of precipitation over Europe and the Mediterranean is impacted by model resolution and the representation of convection (parameterized vs. explicit). We employ a multi-model data-set with three different resolutions (0.44°, 0.11° and 0.0275°) produced in the context of the MED-CORDEX, EURO-CORDEX and the CORDEX Flagship Pilot Study "Convective Phenomena over Europe and the Mediterranean" (FPSCONV). The multi-variate approach is applied to all model ensembles, and to several surface stations where the integrated water vapor (IWV) is derived from Global Positioning System (GPS) measurements. The results show that all model ensembles capture the temperature dependence of the critical value of IWV (IWVcv), above which an increase in precipitation frequency occurs, but the differences between the models in terms of the value of IWVcv, and the probability of its being exceeded, can be large at higher temperatures. The lower frequency of precipitation in convection-permitting simulations is not only explained by higher temperatures but also by a higher IWVcv necessary to trigger precipitation at similar temperatures, and a lower probability to exceed this critical value. The spread between models in simulating IWVcv and the probability of exceeding IWVcv is reduced over land in the ensemble of models with explicit convection, especially at high temperatures, when the convective fraction of total precipitation becomes more important and the influence of the representation of entrainment in models thus becomes more important. Over lowlands, both model resolution and convection representation affect precipitation triggering while over mountainous areas, resolution has the highest impact due to orography-induced triggering processes. Over the sea, since lifting is produced by large-scale convergence, the probability to exceed IWVcv does not depend on temperature, and the model resolution does not have a clear impact on the results. Numéro de notice : P2022-003 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Thématique : POSITIONNEMENT Nature : Preprint nature-HAL : Préprint DOI : 10.21203/rs.3.rs-1397006/v1 Date de publication en ligne : 25/02/2022 En ligne : https://doi.org/10.21203/rs.3.rs-1397006/v1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100754

La campagne Caddiwa dans la région des îles du Cap-Vert / Cyrille Flamant in La Météorologie, n° 115 (2021)  

Public [article]  inLa Météorologie > n° 115 (2021) . - pp 2 - 5 Titre : La campagne Caddiwa dans la région des îles du Cap-Vert Type de document : Article/Communication Auteurs : Cyrille Flamant, Auteur ; Julien Delanoë, Auteur ; Jean-Pierre Chaboureau, Auteur ; Christophe Lavaysse, Auteur ; Marco Gaetani, Auteur ; Olivier Bock , Auteur Année de publication : 2021 Projets : 3-projet - voir note / Article en page(s) : pp 2 - 5 Note générale : bibliographie Le projet Clouds-Atmospheric Dynamics-Dust Interactions in West Africa (Caddiwa) est d’étudier les interactions « systèmes convectifs de méso-échelle-pousières-ondes tropicales » dans la zone de l’Atlantique Nord tropical située au large de l’Afrique de l’Ouest. Langues : Français (fre) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] aérosol [Termes IGN] campagne d'observations [Termes IGN] Cap-Vert [Termes IGN] convection [Termes IGN] image MSG [Termes IGN] lidar atmosphérique [Termes IGN] positionnement par GPS [Termes IGN] poussière [Termes IGN] prévision météorologique [Termes IGN] télédétection spatiale [Termes IGN] tempête Numéro de notice : A2021-978 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueNat DOI : 10.37053/lameteorologie-2021-0081 Date de publication en ligne : 01/11/2021 En ligne : https://doi.org/10.37053/lameteorologie-2021-0081 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100756 [article]

Precipitation frequency in MED and EURO-CORDEX ensembles from 0.44° to convective permitting resolution: what explains the differences? / Minh Ha-Truong (2021)  

Public Titre : Precipitation frequency in MED and EURO-CORDEX ensembles from 0.44° to convective permitting resolution: what explains the differences? Type de document : Article/Communication Auteurs : Minh Ha-Truong, Auteur ; Sophie Bastin, Auteur ; Philippe Drobinski, Auteur ; Lluis Fita, Auteur ; Marjolaine Chiriaco, Auteur ; Jan Polcher, Auteur ; Olivier Bock , Auteur Editeur : Munich [Allemagne] : European Geosciences Union EGU Année de publication : 2021 Conférence : EGU 2021, General Assembly 19/04/2021 30/04/2021 en ligne OA Abstracts only Importance : 1 p. Format : 21 x 30 cm Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] bassin méditerranéen [Termes IGN] convection [Termes IGN] données météorologiques [Termes IGN] Europe (géographie politique) [Termes IGN] modèle atmosphérique [Termes IGN] orographie [Termes IGN] précipitation [Termes IGN] teneur intégrée en vapeur d'eau Numéro de notice : C2021-001 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Thématique : POSITIONNEMENT Nature : Communication nature-HAL : ComSansActesPubliés-Unpublished DOI : sans En ligne : https://meetingorganizer.copernicus.org/EGU21/EGU21-8843.html Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97582

Sensitivity of GPS tropospheric estimates to mesoscale convective systems in West Africa / Samuel Nahmani in Atmospheric chemistry and physics, vol 19 n° 14 (July 2019)  

Public [article]  inAtmospheric chemistry and physics > vol 19 n° 14 (July 2019) . - pp 9541 - 9561 Titre : Sensitivity of GPS tropospheric estimates to mesoscale convective systems in West Africa Type de document : Article/Communication Auteurs : Samuel Nahmani , Auteur ; Olivier Bock , Auteur ; Françoise Guichard, Auteur Année de publication : 2019 Projets : VEGAN / Bock, Olivier, TOSCA / Bock, Olivier Article en page(s) : pp 9541 - 9561 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale [Termes IGN] Afrique occidentale [Termes IGN] analyse de sensibilité [Termes IGN] bande C [Termes IGN] convection [Termes IGN] données GPS [Termes IGN] GAMIT [Termes IGN] GIPSY-OASIS [Termes IGN] gradient de troposphère [Termes IGN] meso échelle [Termes IGN] modèle atmosphérique [Termes IGN] Niger [Termes IGN] propagation troposphérique [Termes IGN] résidu [Termes IGN] retard troposphérique zénithal [Termes IGN] signal GPS Résumé : (Auteur) This study analyzes the characteristics of GPS tropospheric estimates (zenith wet delays – ZWDs, gradients, and post-fit phase residuals) during the passage of mesoscale convective systems (MCSs) and evaluates their sensitivity to the research-level GPS data processing strategy implemented. Here, we focus on MCS events observed during the monsoon season of West Africa. This region is particularly well suited for the study of these events due to the high frequency of MCS occurrences in the contrasting climatic environments between the Guinean coast and the Sahel. This contrast is well sampled with data generated by six African Monsoon Multidisciplinary Analysis (AMMA) GPS stations. Tropospheric estimates for a 3-year period (2006–2008), processed with both the GAMIT and GIPSY-OASIS software packages, were analyzed and intercompared. First, the case of a MCS that passed over Niamey, Niger, on 11 August 2006 demonstrates a strong impact of the MCS on GPS estimates and post-fit residuals when the GPS signals propagate through the convective cells as detected on reflectivity maps from the MIT C-band Doppler radar. The estimates are also capable of detecting changes in the structure and dynamics of the MCS. However, the sensitivity is different depending on the tropospheric modeling approach adopted in the software. With GIPSY-OASIS, the high temporal sampling (5 min) of ZWDs and gradients is well suited for detecting the small-scale, short-lived, convective cells, while the post-fit residuals remain quite small. With GAMIT, the lower temporal sampling of the estimated parameters (hourly for ZWDs and daily for gradients) is not sufficient to capture the rapid delay variations associated with the passage of the MCS, but the post-fit phase residuals clearly reflect the presence of a strong refractivity anomaly. The results are generalized with a composite analysis of 414 MCS events observed over the 3-year period at the six GPS stations with the GIPSY-OASIS estimates. A systematic peak is found in the ZWDs coincident with the cold pool crossing time associated with the MCSs. The tropospheric gradients reflect the path of the MCS propagation (generally from east to west). This study concludes that ZWDs, gradients, and post-fit phase residuals provide relevant and complementary information on MCSs passing over or in the vicinity of a GPS station. Numéro de notice : A2019-572 Affiliation des auteurs : Géodésie+Ext (mi2018-2019) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.5194/acp-19-9541-2019 Date de publication en ligne : 29/07/2019 En ligne : https://doi.org/10.5194/acp-19-9541-2019 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94444 [article]

Multi‐scale observations of atmospheric moisture variability in relation to heavy precipitating systems in the northwestern Mediterranean during HyMeX IOP12 / Samiro Khodayar in Quarterly Journal of the Royal Meteorological Society, vol 144 n° 717 (October 2018 Part B)  

Public [article]  inQuarterly Journal of the Royal Meteorological Society > vol 144 n° 717 (October 2018 Part B) . - pp 2761 - 2780 Titre : Multi‐scale observations of atmospheric moisture variability in relation to heavy precipitating systems in the northwestern Mediterranean during HyMeX IOP12 Type de document : Article/Communication Auteurs : Samiro Khodayar, Auteur ; Beata Czajka, Auteur ; Alberto Caldas-Álvarez, Auteur ; Sebastian Helgert, Auteur ; Cyrille Flamant, Auteur ; Olivier Bock , Auteur ; Patrick Chazette, Auteur Année de publication : 2018 Projets : HyMeX / Richard, Evelyne Article en page(s) : pp 2761 - 2780 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] convection [Termes IGN] coordonnées GPS [Termes IGN] couche atmosphérique [Termes IGN] distribution spatiale [Termes IGN] données météorologiques [Termes IGN] humidité de l'air [Termes IGN] image Cosmo-Skymed [Termes IGN] Méditerranée, mer [Termes IGN] teneur intégrée en vapeur d'eau [Termes IGN] troposphère Résumé : (auteur) The deployment of special instrumentation for the Hydrological Cycle in the Mediterranean Experiment (HyMeX) provides a valuable opportunity to investigate the spatio‐temporal variability of atmospheric water vapour across scales in relationship with the occurrence of Heavy Precipitation Systems (HPSs) in the north Western Mediterranean (WMed) during the Intensive Observation Period (IOP12), which is the focus of this investigation. High‐resolution convection‐permitting COSMO simulations complement the observational network and allow the calculation of on‐line trajectories. In addition to the presence of a favourable large‐scale situation and low‐level convergence, atmospheric moisture changes resulting in conditionally unstable air are identified as responsible for convective initiation (CI). All HPSs within the north‐WMed form in periods/areas of maximum integrated water vapour (IWV; 35–45 kg/m2) after an increase of about 10–20 kg/m2. The most intense events receive moisture from different sources simultaneously and show a sudden increase of about 10 kg/m2 between 6 and 12 h prior to the event, whereas in the less intense events the increase is larger, about 20 kg/m2, over a period of at least 24–36 h. Changes in the lower (∼900 hPa) and mid‐troposphere (∼700 hPa) control the evolution of the atmospheric moisture and the instability increase prior to CI. Spatial inhomogeneities in the lower boundary layer determine the timing and location of deep convection, whereas enhanced moisture in the mid‐troposphere favours intensification. Moister and deeper boundary layers, with updraughts reaching up to 2 km are identified in those pre‐convective environments leading to HPS, whereas dry, shallow boundary layers are found everywhere else. The build‐up time and vertical distribution of the moisture changes are found to be crucial for the evolution and severity of the HPSs rather than the amount of total column atmospheric moisture. Numéro de notice : A2018-550 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/qj.3402 Date de publication en ligne : 09/09/2018 En ligne : https://doi.org/10.1002/qj.3402 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91637 [article]

Frequency of extreme Sahelian storms tripled since 1982 in satellite observations / Christopher M. Taylor in Nature letters, vol 544 n° 7651 (27 April 2017)  

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A seamless weather–climate multi‐model intercomparison on the representation of a high impact weather event in the western Mediterranean: HyMeX IOP12 / Samiro Khodayar in Quarterly Journal of the Royal Meteorological Society, vol 142 n° S1 (August 2016)  

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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)  

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Gravimetric and magnetic anomalies produced by dissolution-crystallization at the core-mantle boundary / Mioara Mandea in Journal of geophysical research : Solid Earth, vol 120 n° 9 (September 2015)    

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New constraints on the origin of the Hawaiian swell from wavelet analysis of the geoid-to-topography ratio / Cécilia Cadio in Earth and planetary science letters, vol 359–360 (15 December 2012)  

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Pacific geoid anomalies revisited in light of thermochemical oscillating domes in the lower mantle / Cécilia Cadio in Earth and planetary science letters, vol 306 n° 1-2 (June 2011)  

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Assimilation de données GPS pour la prévision de la convection profonde / Xin H. Yan (2009) 

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Simulation et assimilation de données radar pour la prévision de la convection profonde à fine échelle / Olivier Caumont (2007) 

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Quantification de la vapeur d'eau troposphérique par GPS (modèles 2D et tomographies 3D) - Application aux précipitations intenses / Cédric Champollion (2005)

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La physique et la Terre / H.C. Nataf (2000)

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