[ES_JOBS_NET] 3-year post-doc position at LSCE: data assimilation for the study of CO2 ecosystem to atmosphere fluxes in Europe

[Gregoire Broquet]

3-year post-doc position at LSCE:

Data assimilation in a regional ecosystem-atmosphere modelling framework 
for the study of CO2 natural fluxes in Europe


LSCE - Laboratoire des Sciences du Climat et de l'Environnement
CEA - L'Orme des Merisiers,
91191 Gif sur Yvette Cedex,
France

Context:

The regional quantification of CO2 ecosystem to atmosphere fluxes and 
the understanding of the underlying processes are critical to predict 
the fate of the European carbon budget and to support greenhouse gas 
(GHG) emission mitigation in the context of global changes. Recent and 
promising approaches rely on the use of data assimilation techniques 
with state of the art ecosystem and transport models. On one hand, the 
atmospheric inversion method derives the surface fluxes that best fit 
with atmospheric CO2 measurements, using an atmospheric transport model. 
On the other hand, complementary systems are currently developed to 
assimilate a wide range of carbon related observations to optimize the 
parameters of process-based terrestrial carbon models (CCDASs). The ICOS 
infrastructure now provides an unprecedented amount of atmospheric CO2 
measurements, eddy covariance carbon, water and energy flux measurements 
and biomass data in Europe that can be exploited with these systems to 
better understand the variations of ecosystem fluxes at high spatial and 
temporal resolution.

The post doc will be connected to the EUROCOM bilateral project (between 
LSCE in France and the University of Lund in Sweden) in collaboration 
with other leading European institute in the field of carbon data 
assimilation. EUROCOM aims at studying the European ecosystem fluxes and 
associated uncertainties at high space and time resolution, based on the 
development of a novel regional modeling framework capable of 
assimilating various carbon cycle measurements from ICOS and from 
satellite observation. EUROCOM will also coordinate an inter-comparison 
of state of the art regional model data fusion approaches (inversions 
and CCDASs) from the European research community.

LSCE is an internationally renowned institute in the field of 
biogeochemical cycles and climate research. It has a strong expertise in 
inverse modeling of GHG fluxes and in the development of carbon cycle 
data assimilation systems. It has developed a variational meso-scale 
inversion framework at European scale solving for 6-hourly fluxes on a 
grid of 50 by 50 km based on the CHIMERE transport model (Broquet et al. 
2011, JGR; Broquet et al. 2013, ACP) as well as an advanced data 
assimilation framework to optimize the parameters of the ORCHIDEE 
vegetation model (see http://orchidas.lsce.ipsl.fr/).

Position summary:

The successful candidate will run and analyse the results of i) the 
European variational atmospheric inversion system and ii) the coupling 
between this system and a regional CCDAS based on a new version of 
ORCHIDEE (including management effects on forest, grass and crops). He 
will thus directly participate to the development and application of the 
first regional model data-fusion approach combining atmospheric 
inversion and optimization of process-based terrestrial model parameters 
to assimilate multiple-data streams (atmospheric CO2, eddy covariance 
fluxes, satellite vegetation indices and possibly biomass measurements). 
He will study the recent dynamics of CO2 ecosystem fluxes in Europe 
(mean fluxes and inter-annual variations) and the underlying processes, 
using the results of this coupled system and the results from the 
University of Lund based on a similar approach. He will also help to 
establish an inter-comparison of regional data assimilation systems in 
Europe that use ICOS observations.

The successful candidate will work nearly full time at LSCE (LSCE, 
CEA-Orme des Merisiers, 91191 Gif sur Yvette cedex, France), with the 
teams dedicated to inverse modeling, ecosystem modeling and GHG 
atmospheric measurements. He will also have the opportunity to spend 
some time at the Lund University for inter-comparison exercises using 
the framework of the Carbon Portal of ICOS.

Applications:

The candidate should have a PhD with experience / knowledge in data 
assimilation, carbon cycle, atmospheric modeling, ecosystem modeling or 
more generally in modeling tools and statistics. The candidate should be 
autonomous and able to work with computing tools such as Fortran and/or 
python, and with complex model codes in UNIX environment. He should also 
have good communication skills.

The salary will be commensurate with experience, on the order of 33000 
euros net per year, including full health care and retirement pension 
benefits. Applications should include a CV and a cover letter, and if 
possible the names of two reference persons. They should be sent to 
Grégoire Broquet (gregoire.broquet at lsce.ipsl.fr 
<mailto:gregoire.broquet at lsce.ipsl.fr>) and Philippe Peylin 
(philippe.peylin at lsce.ipsl.fr <mailto:philippe.peylin at lsce.ipsl.fr>). 
The applications should be sent, and the position will start in as soon 
as possible.

Some relevant publications:

Broquet, G., F. Chevallier, P. Rayner, C. Aulagnier, I. Pison, M. 
Ramonet, M. Schmidt, A. T. Vermeulen, and P. Ciais (2011), A European 
summertime CO2 biogenic flux inversion at mesoscale from continuous in 
situ mixing ratio measurements, Journal of Geophysical Research- 
Atmospheres, 116, doi:Artn D23303.

Broquet, G., et al. (2013), Regional inversion of CO2 ecosystem fluxes 
from atmospheric measurements: reliability of the uncertainty estimates, 
Atmospheric Chemistry and Physics, 13 (17), 9039-9056, doi:Doi 
10.5194/Acp-13-9039-2013.

Kuppel, S., Peylin, P., Chevallier, F., Bacour, C., Maignan, F., and 
A.D. Richardson (2012), Constraining a global ecosystem model with 
multi-site eddy-covariance data, Biogeosciences, 9, 10.

Kuppel, S., Chevallier, F. and P. Peylin, (2013), Quantifying the model 
structural error in carbon cycle data assimilation systems, 
geoscientific model development, 6, 1, 45-55, DOI:10.5194/gmd-6- 45-2013.

Santaren, D., Peylin, P., Viovy, N., and P. Ciais (2007), Optimizing a 
Process based Ecosystem Model with Eddy-Covariance Flux Measurements: 
Part 1. A Pine Forest in Southern France, Global Biogeochemical cycle, 
21 (2).

-- 
Grégoire Broquet <gregoire.broquet at lsce.ipsl.fr>
Laboratoire des Sciences du Climat et de l'Environnement
L'Orme des Merisiers, Bat 701, Point courrier 129
91191 Gif sur Yvette Cedex, France
Tel: +33 (0) 1 6908 8687 / Fax: +33 (0) 1 6908 7716

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