Les missions du poste
Deadline for applications : 31/08/25
Who are we?
Within LOPS, the Ocean and Climate (CLI) group has as main objectives : to diagnose the baseline, variability and trends in the state of the ocean (ocean circulation, water mass properties); to improve understanding of the mechanisms of internal, forced and coupled variability of the ocean-atmosphere-sea ice system; to improve understanding of the processes and their representation in ocean models; and to estimate the role of physical ocean variability on biogeochemical cycles. In order to achieve these objectives, the CLI group relies on in situ and satellite ocean observations, forced and coupled ocean numerical simulations and simplified models. In particular, the CLI group contributes to systematic observation systems (Argo, Deep-Argo, SST, SSS, GOSHIP) in all aspects : funding, organization, deployment, validation, synthesis and analysis. Supported by the technical team (TOIS), the CLI group has carried out numerous oceanographic campaigns, particularly in the North Atlantic.
The LOPS CLI group is currently (as at 01/01/2025) made up of 57 staff, including 24 researchers and 11 permanent technical engineers from the various LOPS supervisory bodies, as well as 17 doctoral students and 5 post-docs/CDDs. You will BE part of this research group as a postdoctoral researcher, under the scientific guidance of his/her postdoctoral supervisors, and reporting to the CLI manager.
What will your mission BE?
We are seeking a physical oceanographer to join the LOPS (Ifremer Centre de Bretagne) in Plouzané (France), to work with the Argo team as part of the CLI group. LOPS is strongly involved in the development and implementation of the Deep-Argo mission and the promotion of oxygen measurements from Argo floats to understand and monitor key indicators and processes related to climate change (ocean heat content, circulation and ventilation, deoxygenation, anthropogenic carbon). The main objective of this position will BE to contribute to the definition of appropriate sampling strategies for Deep-Argo and Argo-O2, in order to guide the Deep-Argo and Argo-O2 implementation plan, with a particular focus on the North Atlantic Ocean. You will mainly involve the analysis of in situ hydrographic data from the Argo network, cruise-based hydrography, and moorings.
What will your activities BE?
In response to human activities CO2 and heat have accumulated in the Earth system over the past decades (von Schuckmann et al., 2023). CO2-induced global warming has accelerated over the last six decades (Minière et al., 2023), leading to unprecedented changes in the Earth system, and in particular in the ocean, which acts as a major heat reservoir storing about 89% of excess heat. Rising ocean temperatures have led to ocean deoxygenation, induced by decreasing solubility, increasing vertical stratification, and changes in ocean circulation patterns that facilitate ventilation of the deep oceans. This is why IT is essential to monitor both ocean heat content (OHC) and changes in oxygen levels as indicators of global climate change.
OHC monitoring has evolved considerably over the last few decades, from ship-based measurements to modern autonomous techniques, which achieved near-global coverage in 2006 thanks to the Argo programme. This has significantly reduced the uncertainty of the OHC at global level (von Schuckmann et al., 2023). At present, one of the sources of error in the estimates of the trend and acceleration of the OHC at global level is the lack of data in the deep ocean (von Schuckmann et al., 2023; Minière et al., 2023). The Deep-Argo mission, based on profiling floats that measure temperature and salinity down to depths of 4,000 or 6,000 m, should fill this gap. The sampling strategy of the Deep-Argo mission consists of 1200 Deep floats carrying out a profile every 10 or 15 days in a 5°x5° square. This strategy, defined 10 years ago by the statistical analysis of a limited data set in the deep layers (Johnson et al., 2015) should enable the detection of local and global decadal trends in the OHC whose amplitude is greater than one standard deviation from the mean. This corresponds to local trends ranging from 1m°C per decade in the abyssal Pacific to around 26m°C per decade in the deep and energetic Southern Ocean. The mission of the person recruited will BE to refine the statistics of Johnson et al. in the North Atlantic using new data sets available in the region (Argo and Deep-Argo data, data from hydrographic campaigns including OVIDE and from RAPID and OSNAP moorings) in order to optimise the design and guide the implementation of Deep Argo in this basin.
Oxygen concentration is an essential ocean variable (EOV). The monitoring of global ocean oxygen content has not yet reached the same level of maturity as that of the OHC. This monitoring should make IT possible to assess its interannual to decadal variability, as well as global ocean (deoxygenation) trends (Kolodziejczyk et al. 2024). Oxygen can also BE used to study biogeochemical processes (e.g. net community production; Riser and Johnson, 2008), and to inform/enhance ocean biogeochemical models (Gregoire et al., 2021); and to study physical processes, such as deep convection/ventilation (e.g., Piron et al., 2016) or circulation pathways and mixing of water masses (e.g., Racapé et al., 2019). What's more, by combining oxygen measurements with temperature and salinity measurements, IT is possible to infer - using transfer functions derived from neural network techniques - nutrient concentrations (nitrate, phosphate and silicate) and carbonate system parameters (total alkalinity, dissolved inorganic carbon, pH and CO2 partial pressure) (Sauzède et al., 2017; Carter et al. 2021), and, with all the above, to obtain an estimate of the anthropogenic carbon fraction (Asselot et al., 2024).
You will BE working on task 1.1 of the European EuroArgo One project, the main objective of which is to have an Argo-O2 and Deep-Argo network with the best cost/benefit ratio to ensure the sustainability of the Argo network and its extensions into the deep and polar oceans, and into biogeochemistry.
Details on your activities
- Assess the current sampling strategies for the Deep-Argo and Argo-O2 networks and how they have been defined and for which scientific objectives;
- Implement the statistical analysis of Johnson et al., 2015 for the Deep-Argo network in the North Atlantic after recovering the available datasets (Argo and Deep-Argo data, data from hydrographic cruises including OVIDE and from the RAPID and OSNAP moorings);
- Implement an equivalent approach for the O2 data. The analysis will begin with a focus on the sub-polar region of the North Atlantic Ocean, before extending, if possible, to the global scale;
- Identify the optimal sampling strategy for the Deep-Argo (North Atlantic) and Argo-O2 networks, enabling significant detection of decadal trends in heat and oxygen content;
- Collaborate with the partners in the Euro-Argo One project involved in task 1.1 of this project and contribute to deliverable D1.5 of the Euro-Argo One project : "Report on the Argo-O2 array sampling strategy and on the revisited Deep-Argo sampling strategy with a focus on the subtropical and subpolar North-Atlantic Ocean and the Nordic Seas.
- To promote and disseminate the results of the analysis through scientific publications and presentations, in particular at meetings of the Euro-Argo ONE project, national, European and international Argo meetings, and scientific conferences.
L'adresse du poste
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Le profil recherché
Who are you?
- PhD in physical oceanography, meteorology, climatology or geophysical fluid dynamics, with proven experience in the field of physics and the use of large databases, defended within the last 3 years.
- Experience of processing Argo data and/or knowledge of biogeochemistry are desirable, but not essential.
You have the following skills, knowledge and experience :
- You should have a background in geophysical fluid mechanics.
- You should have experience with Python and/or Matlab.
- You should BE familiar with various numerical codes for analysis and processing of oceanographic data, including the ability to implement appropriate developments of these existing codes. In addition, you should BE able to create, run and test new codes and produce high quality scientific visualisations.
- You must BE able to write and summarize scientific results effectively.
- You must BE fluent in both spoken and written English.
You have the following qualities :
- Attention to detail
- Initiative
- Ability to work in a team within a collaborative and multidisciplinary environment
Bienvenue chez Ifremer
Join Ifremer, an ally of planetary well-being, to gain a better understanding of and better protection for the ocean.
From the abyss to the surface, from the coast to the open SEA, Ifremer is the French research institute that is wholly dedicated to the Ocean. Its teams carry out research, innovate and produce expert reports to protect the ocean, exploit its resources in a responsible manner and shares marine data.
Ifremer contributes its scientific expertise to throw light on public policies and develops solutions drawn from the ocean to meet the challenges of the ecological transition. Ifremer is the operator of France's oceanographic fleet with its shipbuilding subsidiary Genavir, and imagines, designs and deploys leading edge technological means to solve the ocean's mysteries.
Join our teams, made up of 1500 scientists and research support staff, present all along the coastal areas of France and French overseas territories.
www.ifremer.fr
The Laboratory of Physical and Spatial Oceanography (LOPS, www.umr-lops.fr) is a joint research unit affiliated to Ifremer, and to other three French research and higher education institutions : the French National Centre for Scientific Research (CNRS, www.cnrs.fr), the French National Research Institute for Sustainable Development (IRD, www.ird.fr) and the Université de Bretagne Occidentale (UBO, www.univ-brest.fr). LOPS is one of the seven labs that make up Institut Universitaire Européen de la Mer (IUEM, www-iuem.univ-brest.fr), and one of the three labs of the Océanographie et Dynamique des Ecosystèmes department at Ifremer. Research at LOPS is organized into four working groups : coastal ocean, ocean and climate, satellite remote sensing and air-sea interface dynamics and ocean spatio-temporal scale interactions. The lab maintains and develops a unique know-how in oceanographic measurements at SEA, and the interpretation of satellite remote sensing data.
Infos complémentaires
What are your benefits?
- We have a teleworking agreement and our staff have 12 comp time days and supra statutory leave.
- We allocate a significant budget to developing skills, through individual or collective training actions.
- We have a CSR policy inspired by the purposes of the institute (sustainable mobility allowance, etc.)
How are your activities organised?
- Full-time position.
- 18 months contract
- Active participation in EA-ONE project meetings and possible occasional involvement in other Argo related activities.
