Main research topics
The aim of the work carried out in the ‘Archives and Tracers’ theme is to understand the dynamics and natural variability of the climate on different time and space scales. Particular attention is paid to the sensitivity of marine and continental ecosystems to climatic and anthropogenic changes.
To better understand the natural variability of climate, it is necessary to know how it has evolved in the past (amplitude of changes, periodicity, etc.). Looking into the past also allows us to free ourselves from human disturbance. By analysing different natural archives, we can understand how the complex climate system works and identify and quantify the interactions and flows between its different components : atmosphere, ocean, ice and continental ecosystems. To this end, analysis of past variations of climatic parameters and their impact on ecosystems provides information on how the climate system reacts to natural disturbances (orbital and volcanic). Such data provides a test bed for the ability of numerical climate models to accurately represent the mechanisms involved in changes and their effects.
Analysing and understanding climate variability and the interactions between its different components depends, among other things, on comparing different palaeoclimatic records. For these comparisons to be possible, it is necessary to have a reliable chronology for the different records. The LSCE has developed a whole range of geochronological techniques and tools for dating natural archives, which are also used beyond climatology (prehistory, dating of rock engravings, works of art, etc.).
There are two approaches to assess the sensitivity of marine and continental environments to climate and anthropogenic changes : the first is based on the study of natural climate archives, which provide information on the past impacts of climate change on different ecosystems. The second is based on the study of current ecosystems under the combined pressure of climate change and anthropogenic pressure (rivers, soils, marine environments, etc.).
Managers
- Theme leader: Amaëlle Landais (CNRS)
- Deputy theme leader: Arnaud Dapoigny (CEA)
- Theme assistant: Sandrine Manghi (CEA)
Research tools
For the past fifty years, the LSCE has been developing methods for reconstructing climate parameters by analysing physico-chemical markers in natural archives (ice, marine and lake sediments, loess, trees, molluscs, coral, etc.). To this end, it has a large number of analytical instruments enabling to carry out a wide range of diverse and high-precision measurements.
This research work relies on a high level of commitment from the members of the theme, from taking samples in the field, to analysing the samples (analytical expertise) and interpreting the results :
- Sampling (ice coring, marine or lake sediments, trees, etc.)
- Physico-chemical analyses, particularly isotopic, but also palaeomagnetic, micropalaeontological and sedimentological
- Dating (chronostratigraphy and radiochronology)
- Understanding tracers (recording, fossilisation, preservation of the climatic and/or anthropogenic signal).
