DESCRIPTION :
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., 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.
Post-Doctoral Position In Physical Oceanography on Deep-Argo And Argo-O2 Sampling Strategy M - F H/F
Ifremer
* Plouzané - 29
* CDD
Code d'emploi : Sage-femme (h/f)
Domaine professionnel actuel : Infirmiers Spécialisés
Niveau de formation : Bac+8
Temps partiel / Temps plein : Plein temps
Type de contrat : Contrat à durée déterminée (CDD)
Compétences : Bases de Données, Python (Langage de Programmation), MATLAB, Anglais, Enthousiasme, Minutie ou Attention aux Détails, Esprit d'Équipe, Motivation Personnelle, Dynamique des Fluides, Mécanique des Fluides, Géologie, Hydrographie, Météorologie, Approche Pluridisciplinaire, Océanographie, Sciences Physiques, Recherche Post-Doctorale, Climatologie, Documentation Scientifique, Etudes et Statistiques, Durabilité, Ventilation, Capacités de Démonstration, Changement Climatique
Courriel :
communication@ifremer.fr
Téléphone :
0546762610
Type d'annonceur : Employeur direct
