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Adaptive estimation of the stable boundary layer height using combined Lidar and microwave radiometer observations / Umar Saeed in IEEE Transactions on geoscience and remote sensing, vol 54 n° 12 (December 2016)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 54 n° 12 (December 2016) . - pp 6895 - 6906 Titre : Adaptive estimation of the stable boundary layer height using combined Lidar and microwave radiometer observations Type de document : Article/Communication Auteurs : Umar Saeed, Auteur ; Francesc Rocadenbosch, Auteur ; Susanne Crewell, Auteur Année de publication : 2016 Article en page(s) : pp 6895 - 6906 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte [Termes IGN] analyse de données [Termes IGN] analyse diachronique [Termes IGN] données lidar [Termes IGN] radiomètre à hyperfréquence [Termes IGN] Satellite Microwave Radiometer Résumé : (Auteur) A synergetic approach for the estimation of stable boundary layer height (SBLH) using lidar and microwave radiometer (MWR) data is presented. Vertical variance of the backscatter signal from a ceilometer is used as an indicator of the aerosol stratification in the nocturnal stable boundary layer. This hypothesis is supported by a statistical analysis over one month of observations. Thermodynamic information from the MWR-derived potential temperature is incorporated as coarse estimate of the SBLH. Data from the two instruments are adaptively assimilated by using an extended Kalman filter (EKF). A first test of the algorithm is performed by applying it to collocated Vaisala CT25K ceilometer and humidity and temperature profiler MWR data collected during the HD(CP)2 Observational Prototype Experiment (HOPE) campaign at Jülich, Germany. The application of the algorithm to different atmospheric scenarios reveals the superior performance of the EKF compared to a nonlinear least squares estimator, particularly in nonidealized conditions. Numéro de notice : A2016-920 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2016.2586298 En ligne : http://dx.doi.org/10.1109/TGRS.2016.2586298 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83324 [article]

Diurnal cycle of the intertropical discontinuity over West Africa analysed by remote sensing and mesoscale modelling / Bernhard Pospichal in Quarterly Journal of the Royal Meteorological Society, vol 136 n° S1 (January 2010)    

Public [article]  inQuarterly Journal of the Royal Meteorological Society > vol 136 n° S1 (January 2010) . - pp 92 - 106 Titre : Diurnal cycle of the intertropical discontinuity over West Africa analysed by remote sensing and mesoscale modelling Type de document : Article/Communication Auteurs : Bernhard Pospichal, Auteur ; Diana Bou Karam, Auteur ; Susanne Crewell, Auteur ; Cyrille Flamant, Auteur ; Anja Hünerbein, Auteur ; Olivier Bock , Auteur ; Frédérique Saïd, Auteur Année de publication : 2010 Projets : AMMA & AMMA-2 / Janicot, Serge Article en page(s) : pp 92 - 106 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de géodésie spatiale [Termes IGN] Afrique occidentale [Termes IGN] Bénin [Termes IGN] données météorologiques [Termes IGN] humidité de l'air [Termes IGN] image Météosat [Termes IGN] meso échelle [Termes IGN] mousson [Termes IGN] température au sol Résumé : (auteur) The diurnal cycle of the Intertropical discontinuity (ITD), i.e. the interface at the ground between moist monsoon air and dry Harmattan air, is an important factor in the West African monsoon system. During the whole of 2006, high‐resolution ground‐based remote‐sensing measurements were performed in the area of Djougou, Benin, which made it possible to observe the ITD and the associated sharp gradient of temperature and humidity in detail. In order to extend the point measurements to a three‐dimensional view of the ITD and to enhance the knowledge of the related processes, the mesoscale atmospheric model Meso‐NH was run for a case study (84 h period) in April 2006. In addition Meteosat infrared observations were used to determine the ITD position and its movement. From these observations a northward propagation of the moist air front (ITD) of 8–12 m s−1 was calculated. The propagation speed of the front evaluated from the satellite observations was replicated by the model and the time of the front arrival over Djougou was simulated with a maximum error of 1 hour. With respect to the ground‐based observations, the model was able to reproduce the dynamics and thermodynamics of the front as well as the diurnal cycle of the planetary boundary layer over the study area. This agreement suggests the use of the model to further describe processes in the lower atmosphere at high resolution. Numéro de notice : A2010-643 Affiliation des auteurs : LAREG+Ext (1991-2011) Thématique : POSITIONNEMENT Nature : Article DOI : 10.1002/qj.435 Date de publication en ligne : 11/03/2010 En ligne : https://doi.org/10.1002/qj.435 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90735 [article]

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