CYCLOCARB - Originality, innovative and interdisciplinary aspect

Oceanic Carbon Cycling Response to Global Temperature Changes - CYCLOCARB

Summary – Introduction – Specific objectives approach and methods – Originality, innovative and interdisciplinary aspect – References – Figures and data

Originality, innovative and interdisciplinary aspect

Within CYCLOCARB, the first multiproxies paleo database will be built, allowing to study with the same unique tool the changes in the carbon cycling and its relations with global climate and temperature.

-The quantification of the carbon budget of the climatic system over times will lead to new estimations of the net disequilibrium in carbon cycling across an entire glacial cycle, a major scientific advance when compared to existing estimation for the LGM only ³⁴ (WP2). The soft tissue pump impact on the pCO₂ over glacial/interglacial will be quantified (WP2). The dynamic of the budget and the soft tissue pump variations will facilitate identifying the processes implied and their consequences on glacial-interglacial climate cycles and might affect the design of numerical simulation of the last glacial cycle. Relationships and phasing between carbon cycling changes and climate and temperature variations will be clarified (WP4) on a global scale by minimizing age uncertainties through the use of the multiproxie database.

-The SST database will be used to infer climate sensibility regarding to greenhouse gases forcing’s (WP3), as initially planned for the COMPARE project. We will clarify the evolution of the latitudinal heat gradient over a glacial cycle, and the specificity of each proxy type on a global scale in response the well-known climatic forcings. The evolution of SSTs over the last climatic cycle will be a unique benchmark for upcoming transient climate simulations, and will also be useful for PMIP simulations. As such, this study will have an impact on the climate model community and on future climate change projection and mitigation efforts.

-The extensive surface sediment database will permit the quantification of sedimentary carbon stocks in Exclusive Economic Zones, which could affect French national greenhouse gases inventories and marine carbon stock management ^43,44. New quantitative evaluation of modern and past carbon cycling could pave the way to renewed carbon stock management policies and geoengineering concepts for the mitigation of ongoing global warming.

-The database will be designed with the objective of facilitating any types of advanced statistical analyses, but also to be updated and enhanced after the end of the project. Cutting edge analytical methods (CNN) will be deployed to analyze this extensive dataset. The database produced during this project should also be used by the paleo community, allowing the reproduction of published results, enabling exploration of available datasets for relevant proxies records as well as comparison between records and between proxies. Thus, the database produce during this project will continue to be used after the end of the CYCLOCARB project. Moreover, it should be sufficiently simple and accessible to generate globally distributed datasets that could serve for model/data comparison, or even for public education.

This study relies on the analyses of a multiproxy database. Thus, I will first work on building the database (WP1), then analyze two different aspect of past climate variability separately (WP2-3), and combine them in a single analyses (WP4). Due to the necessity to create, quality control the database, and update the chronological constraints, before exploiting the data, the CYCLOCARB project will last 36 months as scheduled in the Gantt chart below. Quality control of such databases is critical, but extremely long and tedious, and will last at most until month 12. Moreover, my experience with publishing massive datasets and analyses taught me that article review process is much longer than for classic publications. Tackling two different but fundamental aspect of past climate with a single tool that has to be created, and insuring the dissemination of the results furthermore justifies the duration of the project.

The working packages (WP), and the associated trainings, milestones (M) and deliverable (D) are regularly and appropriately distributed over the duration of the project (in month (m)) to insure the success of each of its aspect.

 -WP1, month 1-month 13: Data mining, database construction and quality control, and associated trainings (1-3, see 1.2) will mostly occur during the first year of the effort although updates can occur throughout the project.  A website will be published online after 5 months (D1.1), and first version of the database will be produce after 11 months (D1.2), but updated regularly until the end of the project. Construction of the age model workflow will start before the completion of the database (m9), and the age models created as soon as a first version of the database is ready.

-WP2, m11-m19: Analyses of the carbon cycle proxies will be carried out mostly during the second year of the project, and will end with the submission of a research article (D2, m19).

-WP3, m19-m26: Analyses of temperature proxy will start at month 19 and last 8 months, and a research article will be submitted at m27 (D3).

-WP4, m27-m34: The comparison of reconstructions and proxies will be done between m27 and m34, and a research article submitted at m35.

-WP5, M1-M36: Training and support for administrative supervision of the project will be carried out during the entire project, but annual meetings will be planned with supervisor and administrative staff of the host institution. Mentoring of Master student will occur during the second academic semester of the second and third year of the project. At least two meetings will be scheduled to monitor future career prospects and proposal redaction and submission that will be carried out throughout the project, but more intensively during its second half (M5.1-2).

Training-through-research will be carried out during each tasks with the most appropriate researcher from the host institution (see 1.2). Milestones are set by the middle of each task, indicating meeting with the supervisor and other researchers implied in the task and the working package to monitor the advancement of the project, take decisions on the database format and quality control (M1.1), on the age model workflow (M1.2), on the methods used and on the focus period for carbon cycling (M2) and temperature (M3) reconstruction and the integrated reconstruction (M4).