PhD on reconstruction of carbon cycle-climate interactions
Grenoble Observatory of Sciences of the Universe
- Graduate Position
In close collaboration with our colleagues at the Laboratoire des Sciences du Climat et de l'Environnement (Saclay, France), this PhD project proposes to study several climate and environmental tracers measured in the air trapped in the last 200 m of the EDC ice core over the period 800,000-600,000 years. In particular, it will rely on new measurements of ice air content, O2/N2 ratio, and O2 isotopic composition (?18Oatm) with the goal of producing a new dating of the EDC core over this time interval. New millennial- and sub-millennial scale measurements of atmospheric greenhouse gas concentrations (CO2 and CH4), carbon isotopes (?13C of CO2), and impurities will provide unique sequences of events between climate variations, carbon cycle changes, and orbital forcing during these 'old' interglacials and the preceding deglaciations. These new data will be compared to existing millennial-scale data on more recent interglacials (MIS 5, MIS 7) to refine our understanding of interglacials in the context of the last 800 000 years.
This project consists of (1) an analytical part of data acquisition from the analysis of ice core samples with innovative methods developed in the framework of the national analytical platform PANDA, including a new optical spectrometer for the measurement of CO2 and ?13C of CO2, (2) an analytical part of the new records for dating purposes involving the PALEOCHRONO dating model developed at the IGE (3) an interpretation part to identify the carbon sinks and sources that modulate the CO2 concentration in the atmosphere and the changes in the carbon cycle from simple models and finally (4) a synthesis part to propose new reference climate sequences between 800 000 and 600 000 years ago.
We are looking for a student highly motivated by the study of climate and paleoclimate with a strong background in physics and/or geosciences. This PhD project requires the ability to work as part of a team and to collaborate with teams outside IGE, in France and abroad. A good written and spoken English is required. This project is funded through the project ToBE by the French National Research Council (ANR) and it has some strong interaction with the European Project Beyond EPICA Oldest Ice Core.