Position at IPSL on the complementarity between marine and atmospheric observations to quantify air-sea CO2 fluxes

10 months

Contract: Temporary (10 months)
Gross salary range: 2500 € to 3000 €/ month depending on experience.
Employer: CNRS
Workplace: Saclay and Paris - FRANCE
Skill area: Earth system, oceans, atmosphere, –Engineering.
Application deadline: 01/06/2011

About the laboratory:
The successful applicant will carry out his/her work jointly at two laboratories of the IPSL. The LOCEAN (http://www.locean-ipsl.upmc.fr), a major research laboratory of the IPSL has monitoring programs with research and merchant ships, and instrumented buoys equipped with autonomous pCO2 systems. Observations are collected in the North and tropical Atlantic and in the Southern Ocean. LOCEAN is involved in the international data synthesis project SOCAT (Surface Ocean CO2 Atlas project). LSCE has extensive expertise in climate research, including atmospheric monitoring and inverse modelling of greenhouse gases fluxes from atmospheric observations. LSCE coordinates ICOS, a research infrastructure aiming to decipher the carbon cycle and provide a better estimate of the regional carbon balance. In France, ICOS is particularly seeking to better integrate the ocean and atmospheric components of the infrastructure.

Context:
The principal purpose of carbon cycle observations is to deliver a coherent and accurate picture of natural and anthropogenic CO2 fluxes over land and oceans. The ocean is the largest carbon reservoir and has proven to be stable in absorbing 25% of fossil fuel CO2 emissions over the past five decades, although there are signs of a recent slow-down in the ocean sink since the late 1990s. The ocean includes regions of sources or sinks of CO2 and regional air-sea CO2 fluxes remain highly uncertain. Observations of CO2 fluxes at the ocean surface are collected by ships or moorings, but need extrapolation to produce flux estimates at the scale of ocean gyres. Observations of atmospheric CO2 concentration inverted in atmospheric transport models can provide additional constraints on these air-sea flux estimates, but the fusion between atmospheric and oceanic observations in inversions has not yet received enough attention.

LSCE and LOCEAN research laboratories are opening a 10 month post doctoral position within the French component of the ICOS project (Integrated Carbon Observing system), and more specifically at the interface between the ocean and the atmospheric components. ICOS aims to decipher the carbon cycle and provide a better estimate of the regional carbon balance. In France, ICOS is seeking to better integrate the ocean and atmospheric components of the infrastructure.

Mission:
The successful candidate will identify in the French marine pCO2 observing network, and in global databases like SOCAT, the key ocean parameters that are needed for routine production of air-sea flux estimates and their uncertainties over the sampled regions. The complementarity between marine pCO2 observations and atmospheric CO2 concentration measurements used in inversion modelling will be demonstrated by quantifying the impact of pCO2 sampling and correlation of flux errors in one inversion model.

This work will be conducted in the framework of the preparation of the ICOS European research infrastructure where atmosphere and ocean carbon will be measured, and will deliver recommendations to the French SOERE network of environmental monitoring programs on how to integrate in the future marine and atmospheric carbon observations. These recommendations, formulated in a scientific publication on the joint assimilation of marine pCO2 and atmospheric CO2, will have an important impact in the design of the French marine contribution to ICOS, and its complementarity with the atmospheric networks.

Profile:
The applicant should have a strong expertise in oceanic and/or atmospheric data analysis and a broad interest in biogeochemistry, and ocean-land-atmosphere interactions. A PhD in a related area is required. Of special relevance is proven ability to be dynamic, open and work collaboratively with a team of scientists.

Contact person:
Nathalie Lefèvre
LOCEAN-IPSL, Université Pierre et Marie Curie
UMR 7159 CNRS/IRD/UPMC/MNHN
Case 100, 4 place Jussieu, couloir 45-46, 5ème étage, 75252 Paris Cedex 05, France
E-mail : nathalie.lefevre@locean-ipsl.upmc.fr
Tel : 33 1 44 27 38 21
Fax : 33 1 44 27 71 59

Collaborations with:
At LOCEAN : Nicolas Metzl
At LSCE : Frédéric Chevallier, Michel Ramonet, Philippe Ciais