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3 results on '"campagne de mesures"'

1. Correction of Humidity Bias for Vaisala RS80-A Sondes during the AMMA 2006 Observing Period

Author

Françoise Guichard, Jean-Philippe Lafore, Mathieu Nuret, Jean-Luc Redelsperger, Olivier Bock, Jean-Blaise Ngamini, Anna Agusti-Panareda, Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), LAboratoire de Recherche en Géodésie (LAREG), Ecole nationale des sciences géographiques (ENSG), Institut géographique national [IGN] (IGN)-Institut géographique national [IGN] (IGN), European Centre for Medium-Range Weather Forecasts (ECMWF), ASECNA, Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Agence pour la sécurité de la navigation aérienne en Afrique et à Madagascar (ASECNA)

Subjects
Atmospheric Science, Daytime, 010504 meteorology & atmospheric sciences, Meteorology, 0207 environmental engineering, Ocean Engineering, 02 engineering and technology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, Monsoon, 01 natural sciences, Comparaison de mesures, Méthodes statistiques robustes, Réseau de radiosondages, West africa, law.invention, Atmosphere, law, Correction de biais, Water cycle, 020701 environmental engineering, Réseau GPS, 0105 earth and related environmental sciences, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], business.industry, Afrique de l'Ouest, Humidity, Mousson, Cycle de l'eau, Eau atmosphérique, Climatology, Calibration, Radiosonde, Global Positioning System, Environmental science, Humidité, business, Campagne de mesures
Abstract

During the African Monsoon Multidisciplinary Analyses (AMMA) program, which included a special observing period that took place over West Africa in 2006, a major effort was devoted to monitor the atmosphere and its water cycle. The radiosonde network was upgraded and enhanced, and GPS receivers deployed. Among all sondes released in the atmosphere, a significant number were Vaisala RS80-A sondes, which revealed a significant dry bias relative to Vaisala RS92 (a maximum of 14% in the lower atmosphere, reaching 20% in the upper levels). This paper makes use of a simple but robust statistical approach to correct the bias. Comparisons against independent GPS data show that the bias is almost removed at night, whereas for daytime conditions, a weak dry bias (5%) still remains. The correction enhances CAPE by a factor of about 4 and, thus, becomes much more in line with expected values over the region.

Published
2008
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2. GLORI: A GNSS-R Dual Polarization Airborne Instrument for Land Surface Monitoring

Author

Dominique Guyon, José Darrozes, Sylvia Dayau, Amen Al-Yaari, Remy Fieuzal, Alejandro Egido, Erwan Motte, Pascal Fanise, Frédéric Baup, Nicolas Baghdadi, Pierre-Louis Frison, Mehrez Zribi, Jean-Pierre Wigneron, Centre d'études spatiales de la biosphère (CESBIO), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), National Oceanic and Atmospheric Administration (NOAA), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Interactions Sol Plante Atmosphère (UMR ISPA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro), Territoires, Environnement, Télédétection et Information Spatiale (UMR TETIS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Est Marne-la-Vallée (UPEM), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Interactions Sol Plante Atmosphère (ISPA), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, télédétection, GPS, 0211 other engineering and technologies, 02 engineering and technology, lcsh:Chemical technology, 01 natural sciences, Biochemistry, Sciences de la Terre, Analytical Chemistry, law.invention, remote sensing, law, forêt, Traitement du signal et de l'image, lcsh:TP1-1185, soil moisture, vegetation, biomass, airborne, microwave, L-Band, reflectometry, multistatic radar, GNSS-R, Radar, Instrumentation, Ground truth, Signal and Image processing, campagne de mesures, Vegetation, Atomic and Molecular Physics, and Optics, [SDE]Environmental Sciences, Global Positioning System, donnée aéroportée, Meteorology, Satellite system, Land cover, donnée satellite, Article, Electrical and Electronic Engineering, TELEDETECTION, 021101 geological & geomatics engineering, 0105 earth and related environmental sciences, Remote sensing, BIOMASSE, business.industry, HUMIDITE DU SOL, soil water content, 15. Life on land, REFLECTOMETRIE, GNSS applications, Earth Sciences, zone agricole, Environmental science, Satellite, business, radar
Abstract

[Departement_IRSTEA]Territoires [TR1_IRSTEA]SYNERGIE [Axe_IRSTEA]TETIS-ATTOS; International audience; Global Navigation Satellite System-Reflectometry (GNSS-R) has emerged as a remote sensing tool, which is complementary to traditional monostatic radars, for the retrieval of geophysical parameters related to surface properties. In the present paper, we describe a new polarimetric GNSS-R system, referred to as the GLObal navigation satellite system Reflectometry Instrument (GLORI), dedicated to the study of land surfaces (soil moisture, vegetation water content, forest biomass) and inland water bodies. This system was installed as a permanent payload on a French ATR42 research aircraft, from which simultaneous measurements can be carried out using other instruments, when required. Following initial laboratory qualifications, two airborne campaigns involving nine flights were performed in 2014 and 2015 in the Southwest of France, over various types of land cover, including agricultural fields and forests. Some of these flights were made concurrently with in situ ground truth campaigns. Various preliminary applications for the characterisation of agricultural and forest areas are presented. Initial analysis of the data shows that the performance of the GLORI instrument is well within specifications, with a cross-polarization isolation better than 15 dB at all elevations above 45, a relative polarimetric calibration accuracy better than 0.5 dB, and an apparent reflectivity sensitivity better than 30 dB, thus demonstrating its strong potential for the retrieval of land surface characteristics.

Published
2016
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3. Urban-breeze circulation during the CAPITOUL experiment: observational data analysis approach

Author

V. Masson, G. Pigeon, Julia Hidalgo, Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), FAOC//FA, and Universidade de Vigo

Subjects
Atmospheric Science, 010504 meteorology & atmospheric sciences, Meteorology, Planetary boundary layer, Observation period, Profileur de vent, 010501 environmental sciences, Conditions météorologiques, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, 01 natural sciences, 7. Clean energy, Observation météorologique, Wind profile power law, Insolation, Couche limite de surface, Climatologie urbaine, 0105 earth and related environmental sciences, Mesures d'avion météorologique, Dynamique, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Anticyclone, Radiosondage, Vent, Brise, Température, Analyse des données, Boundary layer, Circulation (fluid dynamics), 13. Climate action, Uhf radar, Campagne de mesures, Geology
Abstract

International audience; An experimental study focused on the urban-breeze circulation observed in Toulouse, South-West of France, during the Intensive Observation Period number 5 (IOP5, 3rd and 4th July 2004) of the CAPITOUL experiment (Feb. 2004 to Feb. 2005) is presented. The influence of the urban breeze circulation on the structure and the dynamics of the Atmospheric Boundary Layer is analysed by using ground stations, wind profilers (UHF radar), radio soundings and aircraft data. The IOP5 is a summertime anticyclonic situation with low wind, strong insulation and a deep boundary layer with a sheared wind profile. The temporal and spatial relationship between the Surface Energy Balance (SEB), the diurnal evolution of the surface temperature and the dynamics of the airflow within the mixed layer are studied for urban and rural sites. The vertical and horizontal structure of the urban heat island are analysed from both surface stations and aircraft data. The nocturnal urban heat island reaches 5 C. In the early morning, the city air becomes 1 C cooler than in the countryside (due to efficient heat storage and building shade on the city urban canopy), then warmer again (1 C) in the afternoon, due to negligible evaporation and strong sensible heat flux in the city. The daytime heat island is also present in altitude, being localized above the city centre at 350m of height (1 C) and advected to leeward at 1100m of height (0.5 C). This diurnal heat island is associated to an urban-breeze circulation characterized by a surface convergence towards the city at low levels and a divergence in upper boundary layer. The urban breeze grows in intensity from 2ms1 (at 12.00 UTC) to 5-6ms1 (at 18.00 UTC). Aircraft measurements show that the urban breeze horizontal extension is 2 to 3 times larger than the city size.

Published
2008
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