67 research outputs found
HyMeX: A 10-Year Multidisciplinary Program on the Mediterranean Water Cycle
Drobinski, P. ... et. al.-- 20 pages, 10 figures, 1 table, supplement material http://journals.ametsoc.org/doi/suppl/10.1175/BAMS-D-12-00244.1HyMeX strives to improve our understanding of the Mediterranean water cycle, its variability from the weather-scale events to the seasonal and interannual scales, and its characteristics over one decade (2010â20), with a special focus on hydrometeorological extremes and the associated social and economic vulnerability of the Mediterranean territoriesHyMeX was developed by an international group of scientists and is currently funded by a large number of agencies. It has been the beneficiary of financial contributions from CNRS; MĂ©tĂ©o-France; CNES; IRSTEA; INRA; ANR; CollectivitĂ© Territoriale de Corse; KIT; CNR; UniversitĂ© de Toulouse; Grenoble UniversitĂ©s; EUMETSAT; EUMETNET; AEMet; UniversitĂ© Blaise Pascal, Clermont Ferrand; UniversitĂ© de la MĂ©diterranĂ©e (Aix-Marseille II); UniversitĂ© Montpellier 2; CETEMPS; Italian Civil Protection Department; UniversitĂ© Paris- Sud 11; IGN; EPFL; NASA; New Mexico Tech; IFSTTAR; Mercator Ocean; NOAA; ENEA; TU Delft; CEA; ONERA; IMEDEA; SOCIB; ETH; MeteoCat; Consorzio LAMMA; IRD; National Observatory of Athens; Ministerio de Ciencia e InnovaciĂłn; CIMA; BRGM; Wageningen University and Research Center; Department of Geophysics, University of Zagreb; Institute of Oceanography and Fisheries, Split, Croatia; INGV; OGS; Maroc MĂ©tĂ©o; DHMZ; ARPA Piemonte; ARPA-SIMC Emilia-Romagna; ARPA Calabria; ARPA Friuli Venezia Giulia; ARPA Liguria; ISPRA; University of Connecticut; UniversitĂ degli Studi dell'Aquila; UniversitĂ di Bologna; UniversitĂ degli Studi di Torino; UniversitĂ degli Studi della Basilicata; UniversitĂ La Sapienza di Roma; UniversitĂ degli Studi di Padova; UniversitĂ del Salento; Universitat de Barcelona; Universitat de les Illes Balears; Universidad de Castilla-La Mancha; Universidad Complutense de Madrid; MeteoSwiss; and DLR. It also received support from the European Community's Seventh Framework Programme (e.g., PERSEUS, CLIM-RUN)Peer reviewe
Apport des sondeurs hyperspectraux au sein du systĂšme global dâobservation pour lâĂ©tude des dĂ©pressions mĂ©tĂ©orologiques
IntĂ©rĂȘt des observations du sondeur satellitaire TOVS pour l'analyse et la prĂ©vision des dĂ©pressions pendant FASTEX
Recent events have reminded us that it is still difficult to predict storms over Europe sufficiently in advance. The FASTEX (fronts and Atlantic storm-track experiment) campaign, conducted in January-February 1997, aims to improve storm forecasting. Our thesis work consisted in studying the interest of the TOVS (tiros-n operational vertical sounder) data on board NOAA satellites for the forecast of FASTEX cyclogeneses. Two research axis were explored: the use of TOVS brightness temperatures to detect upper air precursors to cyclogenesis and the study of their impact on numerical weather prediction. The temperature of the lower stratosphere (TLS) is obtained directly from the brightness temperatures and from additional information contained in the thermodynamical initial guess retrieval (TIGR) database of the lmd. TLS has been studied for 3 FASTEX lows and for the storms of late December 1999. We show that TLS, linked to the dynamic tropopause temperature, reflects tropopause structures such as ridges, thalwegs, tropopause breaks along the cyclonic side of the jet stream and upper air precursors. The TOVS brightness temperatures were then assimilated into the ARPEGE forecast model. For the first time, a targeting study with TOVS data has been performed. To quantify their impact on the forecast, we used the notion of forecast sensitivity to the observations: due to the presence of clouds over the sensitive areas and the key role of the tropopause in cyclogenesis, data from the TOVS microwave sounder are of primary importance as well as those from an infrared channel sounding below the tropopause. Furthermore, we have observed that the sensitivity is related to the assimilation process itself, suggesting the notion of an effective sensitive zone.LâactualitĂ© rĂ©cente nous a rappelĂ© qu'il est encore difficile de prĂ©voir suffisamment a l'avance les tempĂȘtes qui s'abattent sur lâEurope. La campagne FASTEX (fronts and atlantic storm-track experiment) menĂ©e en janvier-fĂ©vrier 1997, a pour objectif dâamĂ©liorer la prĂ©vision de celles-ci. Notre travail de thĂšse a consiste Ă Ă©tudier lâintĂ©rĂȘt des donnĂ©es du sondeur vertical TOVS (tiros-n operational vertical sounder) a bord des satellites de la NOAA pour la prĂ©vision des dĂ©pressions de FASTEX. Deux axes de recherche ont ete explores : l'utilisation des tempĂ©ratures de brillance du TOVS pour dĂ©celer des prĂ©curseurs d'altitude aux cyclogenĂšses et lâĂ©tude de leur impact sur la prĂ©vision numĂ©rique du temps. La tempĂ©rature de la basse stratosphĂšre (TLS) est obtenue directement a l'aide des tempĂ©ratures de brillance et d'une information complĂ©mentaire contenue dans la banque de donnĂ©es TIGR (thermodynamical initial guess retrieval) du LMD. TLS a Ă©tĂ© Ă©tudiĂ©e pour 3 dĂ©pressions de FASTEX et pour les tempĂȘtes de fin dĂ©cembre 1999. Nous avons montre que TLS, liĂ©e a la tempĂ©rature de la tropopause dynamique, reflĂšte des structures de la tropopause tels que dorsales, thalwegs, ruptures de tropopause le long du cote cyclonique du courant-jet et prĂ©curseurs d'altitude. Ensuite, les tempĂ©ratures de brillance du TOVS ont Ă©tĂ© assimilĂ©es dans le modĂšle de prĂ©vision ARPEGE. Pour la premiĂšre fois, une Ă©tude de ciblage avec les donnĂ©es du TOVS a Ă©tĂ© rĂ©alisĂ©e. Pour quantifier leur impact sur la prĂ©vision, nous avons utilise la notion de sensibilitĂ© de la prĂ©vision aux observations : en raison de la prĂ©sence de nuages au dessus des zones sensibles et du rĂŽle clĂ© de la tropopause dans la cyclogenĂšse, les donnĂ©es du sondeur micro-ondes du TOVS sont primordiales ainsi que celles d'un canal infrarouge visant en dessous de la tropopause. De plus, nous avons observe que la sensibilitĂ© est liĂ©e au processus d'assimilation lui-mĂȘme, suggĂ©rant la notion de zone sensible effective
Preparing the assimilation of IASI-NG in NWP models: a first channel selection
International audienc
Homogeneity criteria from AVHRR information within IASI pixels in a numerical weather prediction context
International audienc
Analysis of MTGâIRS observations and general channel selection for Numerical Weather Prediction models
International audienc
Assimilation of IASI observations to enhance the coupling between Numerical Weather Prediction and Chemistry Transport Models
International audienc
4D-Var assimilation of IASI ozone-sensitive radiances in operational global model ARPEGE
International audienc
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