Post-doctoral position in Surface Temperature Downscaling in Arctic regions

(18 months, starting 1st May 2013)

 

A postdoctoral position is proposed by the Laboratoire des Sciences du Climat et de l'Environnement (LSCE, Gif-sur-Yvette, France), and the Laboratoire de Glaciologie et de Géophysique de l’Environnement (LGGE, Grenoble, France), in close collaboration with the CARTEL laboratory (Pr. A. Royer, Université de Sherbrooke, Québec, Canada).

Background: The European project FP7-PAGE21 aims to better understand and quantify the vulnerability of permafrost environments to a changing global climate and to investigate the feedback mechanisms associated with increasing greenhouse gas emissions from permafrost zones. Within this project, remote sensing data products will be developed for model validation and upscaling of site measurements. For this purpose, we have proposed to combine thermal infrared and microwave surface measurements to estimate the surface temperature at regional scale over the main project sites.

Job description: The post-doctoral research scientist will be integrated in the remote sensing team at the LSCE (http://www.lsce.ipsl.fr/), in close interaction with the CARTEL and LGGE laboratories. He/she will work on the downscaling of surface temperature time series developed at CARTEL at 20 km scale on the meso scale sites of the project. The objective is to estimate the surface temperature of the different types of vegetation present inside the 20 km pixel, using prior information given by a land surface model and higher resolution thermal data acquired in cloudless conditions at 1km scale. The methodology is based on the assimilation of the remote sensing data in the land surface model ORCHIDEE (http://orchidee.ipsl.jussieu.fr/). The ORCHIDEE model simulates, from local to global scale, the functioning of the vegetation, including mass (water, carbon) and energy transfers in the soil-plant-atmosphere continuum. It is able to simulate a first guess of the surface temperature for each type of vegetation present in the microwave low resolution pixel. It will be used to constrain the assimilation process based on particle filtering. This method has been successfully developed at LSCE on the SETHYS land surface model and has to be transferred to the ORCHIDEE model. The different tasks to be conducted are the following:

- Analysis of the microwave surface temperature series processed by CARTEL, on the Arctic region on the 2000-2010 snow-free period, and comparison with MODIS thermal infrared surface temperature products (about 4 months)

- Implementation of ORCHIDEE on the PAGE21 sites (100km squares around the experimental station), using the land cover maps developed at LSCE (2months)

- Comparison of the surface temperature simulated to the observed ones on homogeneous pixels and development of the observation operators (2 months)

- Development of the assimilation procedure on the ORCHIDEE model (4 months)

- Processing of the downscaling temperatures on the sites (2 months)

- Publication of the work (2 months)

 

Qualifications: The candidate must have a Ph.D. in the field of Environment, with a background in numerical modelling and/or data processing. In addition the candidate must master the tools such as Fortran (ORCHIDEE is written in Fortran) and Unix. The successful candidate will be expected to attend international conferences and to publish his results in international peer-reviewed journals.

 

Applications: Candidates should submit, by email, a cover letter with a statement of research interests, a CV, as well as the names and addresses of two referees before 30 December 2012 to Catherine Ottlé, LSCE-Orme, CEA-Orme des Merisiers, F-91191 Gif-sur-Yvette, Cedex, France (This email address is being protected from spambots. You need JavaScript enabled to view it. ), Michel Fily, LGGE, BP 96, F-38402 Saint-Martin d’Hères cedex, France (This email address is being protected from spambots. You need JavaScript enabled to view it. ) and Alain Royer, 2500 Bd Université, Sherbrooke, Qc J1K 2R1 Canada (This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Review of applicants will begin soon after the deadline and will be continued until the position is filled. Salary will depend on the previous experience and C.V. of the successful candidate, in agreement with legal and employer regulations.