Détail de l'auteur
Auteur Olivier Bock
Commentaire :
Senior researcher - HDR defense in 2012 - Responsable for Geodesy and atmosphere research area
Autorités liées :
idHAL :
olivier-bock
idRef :
autre URL :
ORCID :
Scopus :
Publons :
G. Scholar :
DBLP URL :
|
Documents disponibles écrits par cet auteur (98)
Ajouter le résultat dans votre panier
Visionner les documents numériques
Affiner la recherche Interroger des sources externes
A high-quality reprocessed ground-based GPS dataset for atmospheric process studies, radiosonde and model evaluation, and reanalysis of HyMeX Special Observing Period / Olivier Bock in Quarterly Journal of the Royal Meteorological Society, vol 142 n° S1 (August 2016)
[article]
Titre : A high-quality reprocessed ground-based GPS dataset for atmospheric process studies, radiosonde and model evaluation, and reanalysis of HyMeX Special Observing Period Type de document : Article/Communication Auteurs : Olivier Bock , Auteur ; Pierre Bosser , Auteur ; Rosa Pacione, Auteur ; Mathieu Nuret, Auteur ; Nadia Fourrié, Auteur ; Ana-Claudia Bernardes Parracho , Auteur Année de publication : 2016 Article en page(s) : pp 56 - 71 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] atmosphère terrestre
[Termes IGN] coordonnées GPS
[Termes IGN] données météorologiques
[Termes IGN] Méditerranée, mer
[Termes IGN] modèle atmosphérique
[Termes IGN] modèle météorologique
[Termes IGN] prévision météorologique
[Termes IGN] radiosondage
[Termes IGN] retard troposphérique zénithal
[Termes IGN] teneur intégrée en vapeur d'eauRésumé : (auteur) In the framework of the Hydrological cycle in the Mediterranean Experiment (HyMeX) project, measurements from more than 1000 ground-based Global Positioning System (GPS) receivers located in the northwestern Mediterranean area are reprocessed using a single piece of GPS software for the period from 1 September 2012 to 31 March 2013. A special screening procedure is developed for the removal of outliers in the GPS Zenith Total Delay (ZTD) data. ZTD data are converted to integrated water vapour (IWV) using surface pressure information from an AROME-WMED operational analysis. The reprocessed ZTD and IWV data are used to assess the accuracy of the near-real time E-GVAP ZTD data assimilated in operational numerical weather prediction systems and to validate the IWV data from the AROME-WMED operational analysis and AROME-WMED reanalysis 1, and from radiosonde observations. The mean differences between E-GVAP and reprocessed ZTD data are not negligible and lie in the range from −3 to +3 mm. The standard deviations of differences are between 4 and 8 mm. The comparisons of IWV from AROME-WMED analyses and the reprocessed GPS data show high quality of the analyses where operational GPS data are assimilated and lower quality where no GPS data are assimilated. Small but significant biases are found in the radiosonde data during daytime (−0.5 to +1.4 kg m−2), but their origin is not determined so far. Thanks to the high spatial density of the reprocessed GPS stations, both the large-scale and small-scale variations in IWV can be documented. The case of HyMeX Intensive Observing Period 8 is presented as an example of a heavy precipitation event. This work suggests that improved quality of the humidity fields can be expected of the future AROME-WMED reanalysis 2 as a result of the assimilation of the reprocessed GPS data. Numéro de notice : A2016-938 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/qj.2701 Date de publication en ligne : 04/11/2015 En ligne : http://dx.doi.org/10.1002/qj.2701 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83370
in Quarterly Journal of the Royal Meteorological Society > vol 142 n° S1 (August 2016) . - pp 56 - 71[article]A multi-instrument and multi-model assessment of atmospheric moisture variability over the Western Mediterranean during HyMeX / Patrick Chazette in Quarterly Journal of the Royal Meteorological Society, vol 142 n° S1 (August 2016)
[article]
Titre : A multi-instrument and multi-model assessment of atmospheric moisture variability over the Western Mediterranean during HyMeX Type de document : Article/Communication Auteurs : Patrick Chazette, Auteur ; Cyrille Flamant, Auteur ; Xiaoxia Shang, Auteur ; Julien Totems, Auteur ; Jean-Christophe Raut, Auteur ; Alexis Doerenbecher, Auteur ; Véronique Ducrocq, Auteur ; Nadia Fourrié, Auteur ; Olivier Bock , Auteur ; Sophie Cloché, Auteur Année de publication : 2016 Article en page(s) : pp 7 - 22 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] données météorologiques
[Termes IGN] lidar Raman
[Termes IGN] littoral méditerranéen
[Termes IGN] modèle de simulation
[Termes IGN] modèle météorologique
[Termes IGN] positionnement par GPS
[Termes IGN] prévision météorologique
[Termes IGN] récepteur GPS
[Termes IGN] teneur en vapeur d'eauMots-clés libres : water vapour lidars Numerical Weather Prediction Models Weather Research and Forecasting model Mediterranean HyMeX cross-validation Résumé : (auteur) The Hydrological cycle in the Mediterranean eXperiment (HyMeX) was held in autumn 2012 during which part of the observational effort was established on Menorca Island to characterize the upwind marine low-level flow. The ground-based Water-vapour Raman Lidar (WALI), the airborne water-vapour lidar LEANDRE 2 and boundary-layer pressurized balloons were implemented during the first Special Observing Period and contributed to characterize water vapour variability in the vicinity of the Balearic Islands, together with the existing network of Global Positioning System receivers. Furthermore, analyses from regional and global numerical weather prediction (NWP) models (AROME-WMED, the ECMWF/IFS NWP system and the Weather Research and Forecasting (WRF) model) were also available over large domains encompassing part of or the entire western Mediterranean basin. We assess the consistency of water vapour mixing ratio (WVMR) profiles and integrated water vapour contents (IWVC) derived from the different datasets by comparing them to a common reference, the ground-based lidar WALI. We use consistency indicators such as root-mean-square errors, biases and correlations. Comparison between WVMR profiles from ground-based and airborne lidars (ground-based lidar and boundary-layer pressurized balloons) leads to a root-mean-square error lower than 1.6 g kg−1 (1.3 g kg−1) when the closest possible air masses are sampled. We observed a good agreement between the vertical WVMR profiles derived from WALI and the numerical models with correlations higher than 0.7 and root-mean-square errors lower than 2 g kg−1. Regarding IWVCs, the models exhibit biases less than 2 kg m−2, root-mean-square errors lower than 2.3 g kg−1 and correlations higher than 0.86 when compared to WALI. Finally, AROME-WMED 48 h forecasts were compared with WALI data composited over eleven 48 h periods. The quality of the forecast does not visibly degrade within the 48 h period from the initial analyses. Numéro de notice : A2016-936 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/qj.2671 Date de publication en ligne : 18/09/2015 En ligne : http://dx.doi.org/10.1002/qj.2671 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83164
in Quarterly Journal of the Royal Meteorological Society > vol 142 n° S1 (August 2016) . - pp 7 - 22[article]Offshore deep convection initiation and maintenance during the HyMeX IOP 16a heavy precipitation event / F. Duffourg in Quarterly Journal of the Royal Meteorological Society, vol 142 n° S1 (August 2016)
[article]
Titre : Offshore deep convection initiation and maintenance during the HyMeX IOP 16a heavy precipitation event Type de document : Article/Communication Auteurs : F. Duffourg, Auteur ; O. Nuissier, Auteur ; Véronique Ducrocq, Auteur ; Cyrille Flamant, Auteur ; Patrick Chazette, Auteur ; Julien Delanoë, Auteur ; Alexis Doerenbecher, Auteur ; Nadia Fourrié, Auteur ; Paolo Di Girolamo, Auteur ; C. Lac, Auteur ; Dominique Legain, Auteur ; M. Martinet, Auteur ; Frédérique Saïd, Auteur ; Olivier Bock , Auteur Année de publication : 2016 Article en page(s) : pp 259 - 274 Note générale : bibliographie Langues : Anglais (eng) Résumé : (auteur) During the first special observation period of the HyMeX program dedicated to heavy precipitation over the western Mediterranean, several Mesoscale Convective Systems (MCSs) formed over the sea and produced heavy precipitation over the coastal regions, as for example during IOP (Intensive Operation Period) 16a. On 26 October 2012, back‐building MCSs formed and renewed over the northwestern Mediterranean Sea while producing heavy rain over the French coastal urbanized regions. This paper analyses the storm evolution along with the ambient flow and the initiation and maintenance mechanisms of the offshore deep convection observed during IOP16a. The suites of water vapour lidars, wind profilers, radiosoundings and boundary‐layer drifting balloons over and along the coast of the northwestern Mediterranean offer a unique framework for validating the convective processes over the sea investigated using kilometre‐scale analyses and simulation. The high‐resolution simulation shows clearly that the convective system is fed during its evolution over the sea by moist and conditionally unstable air carried by a southwesterly to southeasterly low‐level jet. The low‐level wind convergence in this southeasterly to southwesterly flow over the sea is the main triggering mechanism acting to continually initiate and maintain the renewal of convective cells contributing to the back‐building system. The convergence line appears when a secondary pressure low forms in the lee of the Iberian mountains. A sensitivity test turning off the evaporative cooling within the microphysical parametrization shows that the exact location of the main convergence area focusing the heaviest precipitation is determined by small‐scale feedback mechanisms of the convection to the environment. Numéro de notice : A2016--182 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/qj.2725 Date de publication en ligne : 18/12/2015 En ligne : https://doi.org/10.1002/qj.2725 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91816
in Quarterly Journal of the Royal Meteorological Society > vol 142 n° S1 (August 2016) . - pp 259 - 274[article]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)
[article]
Titre : A seamless weather–climate multi‐model intercomparison on the representation of a high impact weather event in the western Mediterranean: HyMeX IOP12 Type de document : Article/Communication Auteurs : Samiro Khodayar, Auteur ; G. Fosser, Auteur ; S. Berthou, Auteur ; Silvio Davolio, Auteur ; Philippe Drobinski, Auteur ; Véronique Ducrocq, Auteur ; Rossella Ferretti, Auteur ; Mathieu Nuret, Auteur ; E. Pichelli, Auteur ; Evelyne Richard, Auteur ; Olivier Bock , Auteur Année de publication : 2016 Projets : HyMeX / Richard, Evelyne Article en page(s) : pp 433 - 452 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] analyse comparative
[Termes IGN] bassin méditerranéen
[Termes IGN] climat méditerranéen
[Termes IGN] convection
[Termes IGN] distribution spatiale
[Termes IGN] données météorologiques
[Termes IGN] humidité de l'air
[Termes IGN] modèle météorologique
[Termes IGN] précipitation
[Termes IGN] vapeur d'eau
[Termes IGN] variabilitéRésumé : (auteur) High Impact Weather (HIW), particularly Heavy Precipitation Events (HPE), are common phenomena affecting the western Mediterranean (WMED) especially in the autumn period. Understanding and evaluating the capability to adequately represent such events in model simulations is one of the main goals of the Hydrological cycle in the Mediterranean Experiment (HyMeX) and the main motivation of this investigation.
In order to gain a better knowledge of the model representation of HPE and related processes we perform a seamless multi‐model intercomparison at the event scale. Limited‐area model runs (grid spacing from 2 to 20 km) at weather and climate time‐scales are considered, four with parametrized and five with explicit convection. The performance of the nine models is compared by analysing precipitation, as well as convection‐relevant parameters. An Intensive Observation Period (IOP12) from the HyMeX‐SOP1 (Special Observation Period) is used to illustrate the results. During IOP12, HPE affected the northwestern Mediterranean region, from Spain to Italy, as a consequence of Mesoscale Convective Systems (MCSs) which initiated and intensified in the area of investigation. Results show that: (i) the timing of the maximum precipitation seems to be linked to the representation of large‐scale conditions rather than differences among models; (ii) Convection Permitting Models (CPMs) exhibit differences among each other, but better represent the short‐intense convective events. All four convection‐parametrized models produce a large number of weak and long‐lasting events. Regional Climate Models (RCMs) capture the occurrence of the event but produce notably lower precipitation amounts and hourly intensities than CPMs and Numerical Weather Prediction (NWP) models with parametrized convection; (iii) these differences do not seem to come from mean moisture or Convective Available Potential Energy (CAPE) which are in the same range for all models, but rather from differences in the variability and vertical distribution of moisture and the triggering of deep convection.Numéro de notice : A2016--174 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1002/qj.2700 Date de publication en ligne : 29/10/2015 En ligne : https://doi.org/10.1002/qj.2700 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91787
in Quarterly Journal of the Royal Meteorological Society > vol 142 n° S1 (August 2016) . - pp 433 - 452[article]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)
[article]
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 / Richard, Evelyne Article en page(s) : pp 335 - 346 Note générale : biblographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale
[Termes IGN] circulation atmosphérique
[Termes IGN] convection
[Termes IGN] coordonnées GPS
[Termes IGN] Corse
[Termes IGN] couche atmosphérique
[Termes IGN] données météorologiques
[Termes IGN] teneur intégrée en vapeur d'eauRésumé : (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 Affiliation des auteurs : LASTIG LAREG+Ext (2012-mi2018) 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
in Quarterly Journal of the Royal Meteorological Society > vol 142 n° S1 (August 2016) . - pp 335 - 346[article]Water vapor measurements by mobile Raman lidar over the Mediterranean Sea in the framework of HyMeX: application to multi-platform validation of moisture profiles / Julien Totems in EPJ Web of Conferences, vol 119 (2016)PermalinkCouplage lidar Raman et GPS pour le sondage de la vapeur d'eau atmosphérique et le positionnement précis / Leslie David (2015)PermalinkComparison of individual and combined zenith tropospheric delay estimations during CONT08 campaign / Arnaud Pollet in Journal of geodesy, vol 88 n° 11 (November 2014)PermalinkLes systèmes de positionnement et de navigation par satellite : Application à la météorologie et à la climatologie / Olivier Bock in La Météorologie, n° 86 (août 2014)PermalinkHyMeX-SOP1, the field campaign dedicated to heavy precipitation and flash flooding in the northwestern Mediterranean / Véronique Ducrocq in Bulletin of the American Meteorological Society, vol 95 n° 7 (July 2014)PermalinkA high-quality, homogenized, global, long-term (1993–2008) DORIS precipitable water data set for climate monitoring and model verification / Olivier Bock in Journal of geophysical research : Atmospheres, vol 119 n° 12 (2014)PermalinkDORIS tropospheric estimation at IGN : Current strategies, GPS intercomparisons and perspectives / Pascal Willis (2014)PermalinkAccuracy assessment of water vapour measurements from in-situ and remote sensing techniques during the DEMEVAP 2011 campaing at OHP / Olivier Bock in Atmospheric measurement techniques, vol 6 n° 10 (October 2013)PermalinkComparison of IASI water vapour products over complex terrain with COPS campaign data / Guido Masiello in Meteorologische Zeitschrift, vol 22 n° 4 (August 2013)PermalinkDORIS and GPS monitoring of the Gavdos calibration site in Crete / Pascal Willis in Advances in space research, vol 51 n° 8 (April 2013)Permalink