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Professeurs

Pierre Gauthier

Sciences de la terre et de l’atmosphère

Université du Québec à Montréal
Université du Québec à Montréal
Case postale 8888, succursale Centre-ville
Montréal (Québec) H3C 3P8 Canada

Téléphone : 514 987-3000 #3126
Courriel : gauthier.pierre@uqam.ca
Lieu d'encadrement : UQÀM
Habilitation : Habilitation à diriger

Résumé
. RESEARCH PROPOSAL My research interests are related to data assimilation methodology and its relationship with atmospheric dynamics and predictability. I am also interested in applications of data assimilation to coupled systems. I was involved in the development of a 4D-Var assimilation system for an atmospheric-chemistry model in the framework of a study funded by the European Space Agency: this project was carried out jointly with the Belgium Institute for Space Aeronomy and York University. This raised many issues as chemistry and dynamics act on a wide range of temporal scales. Another project I am involved in at the moment is concerned with the assimilation for a coupled atmosphere-ocean model. This is developed through to the research network on Prediction and Predictability of the Global Atmosphere-Ocean System from Days to Decades funded by the Canadian foundation on Climate and Atmospheric Sciences (CFCAS). The approach being pursued is concerned not only with the analysis of initial conditions but also with the estimation of physical parameters associated heat, humidity and momentum exchanges between the ocean and the atmosphere. My interests lie strongly with the mathematics of data assimilation associated with problems encountered in specific applications. Recently, I worked on problems associated with the so-called dual form of variational data assimilation. This work is the subject of the thesis of my Ph.D. student at McGill, Ms. Amal El Akkraoui. This approach is of interest as it may offer a significant simplification in the development of the weak-constraint 4D-Var that permits to take into account model error. This avenue is being investigated at several centres for assimilation problems where initial conditions is not the only source of forecast error. Particularly, this is important for reanalyses for which it is important to resolve processes acting on longer time scales. It also concerns parameter estimation problem like the one I am looking at the moment for the coupled ocean-atmosphere system. I am also interested in new approaches that permit to evaluate the impact of observations on the quality of analyses and forecasts. This subject is the topic of the Ph.D. thesis of Mrs. Cristina Lupu at UQAM. These methods have revealed that there are synergistic relationships between observations of different types. The synergy is subtle because it does not imply that observations need to be collocated. The THORPEX working group on Data Assimilation and Observing Systems (DAOS-WG) is particularly interested in questions associated with the design of the global observing system to improve forecasts of high-impact weather. These methods offer a detailed perspective of the impact of observations and they are now being implemented at several weather prediction centres to monitor the value of the assimilated observations. Our understanding of the fundamental processes that govern the evolution of the atmosphere is achieved through observing and modeling the numerous physical processes based on first principles. Numerical modeling is in a sense the laboratory in which all of our knowledge is encompassed within a numerical model the simulations of which then need to be compared to observations. I am involved in the CLUMEQ consortium which aims at providing high-performance computing resources to the participating universities (McGill, Laval, UQAM, Ouranos). Using the CLUMEQ resources would offer to academic research a numerical “laboratory” equipped with modeling and assimilation capabilities. This would open several opportunities to be involved in ongoing international projects related to the modeling and observation of the Earth system and its applications to climate and weather studies. Particularly, there is a significant effort within the THORPEX program to evaluate the impact of observations collected during observation campaign like the THORPEX Pacific-Asia Regional Campaign (T-PARC). This common effort would bring together the atmospheric research community in the Montréal area and even spark collaborations nationally and internationally. This would be a very exciting perspective in my view.



Références
Amal El Akkraoui,a* Pierre Gauthier,a,b Simon Pellerinc and Samuel Buisd
a Department of Atmospheric and Oceanic Sciences, McGill University, Canada
b Department of Atmospheric and Earth Sciences, Universit´e du Qu´ebec `a Montr´eal, Canada
c Meteorological Research Division, Environment Canada, Canada
d European Centre for Research and Advanced Training in Scientific Computation (CERFACS), France

Extension of 3DVAR to 4DVAR: Implementation of 4DVAR at the
Meteorological Service of Canada
PIERRE GAUTHIER, MONIQUE TANGUAY, STÉPHANE LAROCHE, AND SIMON PELLERIN
Meteorological Research Division, Environment Canada, Dorval, Québec, Canada
JOSÉE MORNEAU
Meteorological Service of Canada, Environment Canada, Dorval, Québec, Canada
(Manuscript received 19 April 2006, in final form 29 August 2006)

Mathematics in Atmospheric Sciences:
An Overview
Pierre Gauthier
Department of Earth and Atmospheric Sciences
Universit´e du Qu´ebec `a Montr´eal
pierre.gauthier@uqam.ca



Liste des synthèses encadrés en tant que directeur

Titre
L’observation de l’atmosphère et de l’environnement (2008)

Auteur
Lupu, Cristina





Liste des thèses encadrés en tant que directeur

Titre
Étude sur l’observabilité de l’atmosphère et l’impact des observations sur les prévisions météorologiques (2010)

Auteur
Lupu, Cristina