November 2012
Message 81

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[Met-jobs] Post-doctoral Fellow (biogeochemistry and hydrology) at L-IPSL of the Institut Pierre-Simon Laplace (France)

From "Roger Brugge" <>
To "" <>
Date Tue, 27 Nov 2012 09:21:54 +0000

Forwarded from CLIMLIST...

Post-doctoral fellow offer in biogeochemistry and hydrology (Modeling
inland water greenhouse gas fluxes)

The excellence laboratory L-IPSL of the Institut Pierre-Simon Laplace
offers a post-doctoral position of 2 years to integrate into the IPSL
Earth System Model some of the key previously neglected inland aquatic
processes than form the so called “boundless carbon cycle”. The proposed
post-doctoral position project is a reaction to the growing awareness
that inland waters contribute significantly to global greenhouse gas
(GHG) fluxes, and to the realization that their sensitivity to projected
climate change and eco-hydrological disturbance is poorly constrained.

Context: The conventional wisdom is that inland waters
simply transport terrigenous organic carbon to the oceans. This view is
perpetuated by current models of the global carbon cycle that largely
ignore inland waters as represented in, for instance, the
Intergovernmental Panel for Climate Change (IPCC) – Fourth Assessment
Report (FAR), or the Integrated Global Observing Strategy
report (GEO-Carbon). In the five years since the publication of IPCC’s
FAR in 2007, it has become apparent that the global flux of GHGs from
inland aquatic sources to the atmosphere is much larger than previously
suspected (Battin et al., 2008; 2009; Butman and Raymond, 2011;
Bastviken et al., 2011; Barros et al., 2011). Thus, recently
published estimates indicate that inland waters degas from 0.8 Pg
(1Pg= 109 metric tons) of carbon per year (excluding wetlands, Cole et
al. 2007), up to 3.3 Pg C y-1 (including wetlands, Tranvik et al., 2009;
Battin et al., 2008; 2009; Aufdenkampe et al., 2011; Butman and Raymond,
2011), the latter estimate of similar magnitude to the terrestrial
carbon sink of 2.8 Pg C y-1 (Canadell et al. 2008). Only recently have
regional scale carbon balances begun to consider these fluxes (e.g.
Luyssaert et al., 2012), but large knowledge gaps remain concerning
their magnitude and their ultimate significance for global carbon cycle
models. Current estimates based on global surveys and ‘bottom up’
extrapolations from streams and rivers in the United States for example
indicate that this GHG flux is significant relative to the total
anthropogenic flux of carbon to the atmosphere, with emissions from the
northern hemisphere temperate zone (25oN-50oN) rivers alone estimated
to be c. 0.5 Pg annually (Butman and Raymond, 2011). Additionally, a
recent survey of CH4 emissions from inland aquatic systems (lakes,
reservoirs and rivers) indicated annual CO2-equivalent methane emissions
of a similar magnitude (0.65 Pg of C as CO2 equivalent; Bastviken et
al., 2011). These recent estimates necessitate a paradigm shift from
the traditional depiction of streams, rivers and other inland freshwater
bodies as inert conduits and reservoirs, to one in which the kinetics of
climate-sensitive GHG production by
aquatic biogeochemical transformation reactions, hydrologically driven
soil gas flushing from riparian zones and the dynamics of gas transfer
processes at water/air interfaces are incorporated into realistic
‘boundless carbon cycle’ models.

Despite the potential importance of these GHG emissions, their
inclusion, even under a simplified form, in current Earth System Models
is still missing, although several research teams began to work in that
direction. The sensitivity of lateral C fluxes in aquatic systems to
global change and eco-hydrological disturbances is largely unknown, and
their overall significance for Earth’s global carbon budget remains to
be established as well. Much previous work on regional scale
carbon balances has focused on terrestrial sinks and sources, but it is
increasingly appreciated that flux measurement techniques that are
applied widely to terrestrial systems (e.g. Eddy covariance methods) are
inappropriate or require re-evaluation for aquatic systems.

Description of work: The postdoctoral fellow will interact with
researchers at LSCE and SISYPHE laboratories, part of L-IPSL, and
incorporate a set of simplified parameterizations on the land surface
scheme ORCHIDEE of the IPSL Earth System model the following processes :
C emissions from soils to rivers headstreams for DIC and DOC, with a
highly parametric inclusion of chemical alteration fluxes of C from
atmospheric origin, CO2 evasion data from rivers and floodplains, C
burial in lakes and freshwater sediments and CO2 emissions from
estuaries ( the later using the global upscaling model developped by
Pierre Regnier at University of Utrecht). The ORCHIDEE model enabled for
carbon transport from soil to rivers and lakes will be tested and
calibrated against a new pCO2 global database and river fluxes of DOC,
DIC (COSCAT database of 150 catchments;
<>). The model
will be applied in the second year for characterising the presently
unknown atmospheric feedbacks (positive and negative) between inland
aquatic carbon evasion fluxes and drivers such as climate change and
anthropogenic eco-hydrological disturbance.

Supervision team:The researcher with a PhD in earth system science,
will be hired by CNRS and will be hosted at LSCE in Saclay (France)
while working in close collaboration with SISYPHE in Paris. The work
will be in a project team led by Philippe Ciais, including also Laurent
Bopp, Josette Garnier, Sebastiaan Luyssaert and Christophe Rabouille.

Duration and salary:Thepost-doctoratewillberecruitedfor24months with a
net monthly salary around 2000 euros, commensurate with experience. This
includes social services and health insurance.

Contact for applications:Applications should include a vita, a
statement of research interests and the names of at least two references
including e-mail addresses and telephone numbers. Applications should be
submitted by e-mail to Philippe Ciais (

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