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Reference : UMR8539-ISARIC-029
Workplace : PARIS 05
Date of publication : Friday, April 24, 2020
Type of Contract : FTC Scientist
Contract Period : 24 months
Expected date of employment : 1 October 2020
Proportion of work : Full time
Remuneration : Grille CNRS selon expérience
Desired level of education : 5-year university degree
Experience required : Indifferent
The Laboratoire de Météorologie Dynamique (LMD) is seeking a postdoctoral research scientist to work on the European project ROADMAP (call JPI-Climate). The main objective is to study the influence of tropical modes of variability like ENSO (El-Nino Southern Oscillation) or the MJO (Madden-Julian Oscillation) on the North Atlantic atmospheric circulation. This influence, often referred to as tropics-extratropics teleconnection patterns, is of great importance for subseasonal and seasonal weather forecasting at midlatitudes. Various types of mechanisms have been proposed in the literature to understand this tropics-extratropics relationship. One type, called the tropospheric pathway, involves quasi-stationary Rossby waves emitted from the tropics and interactions with synoptic eddies in the troposphere. Another type, called the stratospheric pathway, emphasizes the role played by the stratospheric sudden warmings in transmitting the signal from the Pacific to the Atlantic. Some studies also emphasized that the stratosphere modulates the response initially provided by the tropospheric pathway. Some other authors showed that the North Atlantic response to tropical convection anomalies in the Pacific is strongly dependent on the background flow and this may create years with weak-to-no response and years with strong response. The debate is still ongoing and it is still not clear what are the relative roles of tropospheric and stratospheric pathways and the key properties of the background flow that help to create such a teleconnection pattern. The main goal of the postdoctoral work is to tackle this problem by performing numerical experiments of the model ICO-LMDZ using the new dynamical core of the atmospheric model at IPSL called DYNAMICO. The project supervisor at LMD is Gwendal Rivière working in the team « Dynamics of atmosphere and ocean ». The work will be done in collaboration with Sébastien Fromang from Laboratoire des Sciences du Climat et de l'Environnement (LSCE).
- Development of model forcings : one forcing will be set to get a model climatology close to the observations and another forcing will reproduce the heating associated with ENSO and MJO events.
- Development of an ensemble of simulations with the model (moist vs dry dynamics, with and without relaxation of the stratosphere toward its climatology).
- Analysis of the simulations outputs; statistical analysis and dynamical interpretation from vorticity and streamfunction budgets.
- Synthesis of the results : writing of peer-reviewed publications and presentation of the results in conferences.
The offered position is dedicated to a researcher in atmospheric physics and dynamics. A PhD thesis in atmospheric physics, meteorology or climate dynamics is required.
- The candidate should know the main physical and dynamical processes involved in atmospheric circulation.
- The candidate should have experience in running a numerical model and in analyzing large meteorological datasets like climate models output or reanalyses products.
- We also expect the candidate to have good programming skills in some langages like Fortran, R, Python, Matlab or Ferret.
- Very good written and oral communication skills in English are required.
- The candidate should be able to work inside a team and to communicate with colleagues and students.
-The LMD is an internationally well-recognized research laboratory working on atmospheric dynamics, atmospheric physics, air pollution and climate variability and dynamics. It depends on the Centre National de la Recherche Scientifique (CNRS), Ecole Normale Supérieure (ENS), Paris Sciences Lettres (PSL) university, Ecole Polytechnique, and Sorbonne Universités. Different complementary approaches are followed: numerical modelling, instrumental development for observations and theoretical approaches. The recruited researcher will work within the team “Dynamics and Physics of the Atmosphere and Ocean” (DPAO). His office will be in the LMD site located at Ecole Normale Supérieure (24 rue Lhomond, 75005 Paris). He/she will mainly work with Gwendal Rivière and Sébastien Fromang from LSCE. Finally, the recruited researcher will participate in different meetings and will have regular interactions with other participants of the European project ROADMAP.
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