Postdoc on modelling of the greenhouse gas balance of Europe, LSCE/France

Postdoc on modelling of the greenhouse gas balance of Europe

We seek a postdoctoral researcher to work on modelling of the greenhouse gas balance of Europe at the Laboratoire des sciences du climat et de l'environnement (LSCE) in Gif-sur-Yvette, France, within the EU-funded GHG-Europe project.

Description

The wealth of data collected on the carbon balance of Europe in the framework of the CarboEurope project (2004-2008) has not yet yield all its secrets. More than hundred eddy flux towers are in operation, now covering cultivated ecosystems croplands and grasslands. Forest inventories provide information from more than 100,000 plots. The challenge is to develop and apply terrestrial biosphere models that integrate spatially and temporally the fluxes of CO2, CH4 and N2O between European ecosystems and the atmosphere, and the carbon pools distribution. In Europe, all ecosystems are quite intensively managed, and so terrestrial biosphere models have to evolve from describing natural vegetation as a 'green sponge' responding just to climate and CO2.

Europe is also a region of the world with high rate of climate variability, being the nexus of positive feedbacks of the land surface during summer heatwaves and drought. Thus, the GHG balance of the continent is sensitive to climate variability, and this sensitivity is modulated by human management.

During the summer 2003 heatwaves for instance, ecosystems have been shown to loose CO2 to the atmosphere on average, but winter crops with a peak of growth before the heatwaves remained much less affected than summer crops. The interplay between management, climate and atmospheric composition changes involving rising CO2, N-deposition and possibly tropospheric O3 changes must be better understood to quantify and understand the GHG-balance of Europe.

The goal of the proposed post in the framework of the EU-funded GHG-Europe project is to investigate the causes of the variability of Europe's greenhouse gas balance over the past 100 years, with special focus on the past 10 years with more data available. The relative contributions of land use, management intensity, N-deposition, CO2, and climate forcing to the European greenhouse gas balance will be studied using the ORCHIDEE terrestrial biosphere model. This model is interfaced with a forestry model (FAGACEE), a managed grassland model (PASIM) and a generic crop model (STICS), thus allowing to account - although in a coarse manner - for management impacts on GHG fluxes. Factorial experiments driven by offline climate data will be made using versions of the model with and without several different processes. The resulting modelled fluxes of CO2, N2O (possibly CH4) will be inter-compared and verified using observations, to quantify the regional contribution of each process, and their uncertainty. Then in a second step, the inter-annual variability of regional GHG fluxes will be attributed to the different processes.

The research will be carried out at the LSCE laboratory, in the terrestrial biogeochemistry modelling group, with Nicolas Viovy and Nicolas Vuichard and Philippe Ciais in collaboration with MPI-Biogeochemistryinstitute with Markus Reichstein, and Martin Jung. The position is for a CEA postdoc, with funding for 3.5 years, and salary of approximately 2000-2500 Euros/month commensurate with experience. The required qualification for this position is a PhD in terrestrial biogeochemistry, atmospheric science or related field. Experience with numerical Earth system modelling (i.e. FORTRAN), and data analysis (e.g. Matlab, IDL, ferret, or equivalent) programming languages is essential. Applicants should submit a CV, including publication list, and at least two references to: nicolas.viovy@lsce.ipsl.fr tel. +33 1 69 08 77 17.