Postdoctoral (2-year) Researcher in Modelling Atmospheric Chemistry and Isotopic Ratios of O2 for Improved Estimate of Past Global Biosphere Productivity
Laboratoire des Sciences du Climat et de l'Environnement/Université de Versailles Saint-Quentin-en-Yvelines
The Laboratoire des Sciences du Climat et de l’Environnement (LSCE) is a joint research unit of the CEA (Commissariat à l’énergie atomique et aux énergies alternatives), the CNRS (Centre national de la recherche scientifique) and the Université de Versailles Saint-Quentin (UVSQ). The LSCE is a research laboratory that studies past, present and future climate, focusing mainly on biogeochemical cycles and climate characteristics and evolution, in order to predict the climate changes our planet will have to face. LSCE’s research on the carbon cycle and the role of vegetation in the Earth System is internationally recognized. LSCE is part of the Institut Pierre-Simon Laplace (IPSL). LSCE is globally recognized by its fundamental role in IPCC Assessement Reports and numerous international collaborations such as Coupled Model Intercomparison Project (CMIP) or Paleoclimate Model Intercomparison Project (PMIP).
Climate: Past, Present & Future (CL)
We are looking for a motivated post-doctoral researcher to work on atmospheric chemistry during the past climate and its impact on the interpretation of the ice-core records of the oxygen isotopes of air O2. The post holder will be based at Laboratoire des Sciences du Climat et de l’Environnement (LSCE, near Paris, France) and Laboratoire Atmosphères, Observations Spatiales (LATMOS, Paris, France). She/He will work under the guidance of Dr. Ji-Woong Yang and Dr. Slimane Bekki in collaboration with researchers and engineers at both laboratories.
In order to better predict future climate and carbon cycle change, it is essential that we understand the past variations of the global biosphere productivity and its control mechanism, as the global biosphere productivity is an important carbon flux between the atmosphere and the biosphere. Existing paleo-productivity proxy records from sediment cores are, however, indirect geochemical tracers and exhibit spatial heterogeneities, making it difficult to estimate the global biosphere productivity. Instead, the triple isotopic composition of air oxygen (O2) trapped in polar ice cores is the unique tracer of global biosphere productivity. We have analyzed the EPICA Dome C ice-core samples to reconstruct the variability of global biosphere productivity over the last 800,000 years (Yang et al., 2022, Science, https://www.science.org/doi/full/10.1126/science.abj8826)
However, many uncertainties or unknowns still exist about this fairly new tracer. The most important uncertainty originates from lack of knowledge on the isotope fractionation in the stratosphere in the past, and no proxy record exists so far. This will be addressed by combining simulations using a box model describing oxygen isotope fractionation in the stratosphere and 3-D climate-chemistry model with past cold climate boundary conditions. The successful candidate will i) perform climate-chemistry model simulations with PI (preindustrial) and LGM (last glacial maximum) boundary conditions, ii) apply the chemistry reaction box model to calculate the isotopic composition of stratosphric O2, iii) refine the global biosphere productivity estimate during the past climate, and iv) communicate the results in the international conferences and via publication in the international peer-review journals.
This position is fully funded (by French National Research Agency) for up to 24 months (further extension will be possible depending on funding). This position will remain open until filled. The starting date is flexible before summer 2024.
Application should be sent via e-mail to Ji-Woong YANG (firstname.lastname@example.org) including (i) a cover letter stating your motivation for applying to this position, research experience, relevant skills and interest, (ii) a complete CV including a list of publications, and (iii) the name and contact information of professional references (up to three). Applications received by January 1, 2024, will be given full consideration.
For further information or any other informal enquiries about the position, please do not hesitate to contact me via email (email@example.com).