Descripción del proyecto
Información novedosa sobre las transiciones glaciales-interglaciales
Las glaciaciones constituyen los mayores cambios climáticos acontecidos durante el Cuaternario. Durante este período el ritmo de las desglaciaciones cambió a una periodicidad glacial-interglacial de 100 ka entre hace 1 250 y 700 ka. La causa de tal transición todavía es objeto de discusión. El equipo del proyecto interdisciplinar ICORDA, financiado con fondos europeos, estudiará los mecanismos de las desglaciaciones mediante la identificación de influencias —como el forzamiento de la insolación, el tamaño de la capa de hielo y la concentración de gases de efecto invernadero en la atmósfera— en las muestras del proyecto EPICA (European Project for Ice Coring in Antarctica) en el domo Concordia, que abarcan un período de 800 ka, y un testigo de hielo que comprende los últimos 1 500 ka. En el proyecto se investigará además la forma en la que se determina la cronología de los testigos de hielo.
Objetivo
The Quaternary period (last 2600 thousands of years, hereafter ka) is the ideal period to evaluate our understanding of climate processes with general circulation models (GCM) used for prediction of future climate. During this period, the largest climate changes are glacial – interglacial transitions, hereafter terminations, the last termination being a classical benchmark for GCM. The rhythm of terminations changed from a world associated with a 40 ka periodicity to a world associated with a 100 ka glacial – interglacial periodicity between 1250 and 700 ka. The cause for this transition is a long debated question highlighting that the causes and mechanisms of terminations are still poorly understood. The timing and amplitudes of terminations indeed result from multiple influences of insolation forcing, ice sheet size, atmospheric greenhouse gases (GHG) concentration as well as shorter (millennial) scale climate variability. The big challenge of ICORDA consists in solving major puzzles on the mechanisms of terminations by deciphering these different influences using two key Antarctic ice core records: EPICA Dome C covering the last 800 ka and an ice core to be drilled in the coming years and covering the last 1500 ka. While ice cores provide unique continuous and high resolution climatic and GHG records, they are still too poorly dated on long timescales to address the aforementioned challenge. ICORDA aims at rethinking the way ice core chronology is built for decreasing drastically the associated uncertainties. This will be done by (1) developing a mechanistic approach for the interpretation of isotopic tracers used for ice core dating and (2) combining numerous low to mid latitude ice core tracers to provide a global picture of climate change during terminations. The strategy involves interdisciplinarity between climate, geochemistry, ecophysiology and innovative instrumental developments as well as field, laboratory experiments and modeling.
Ámbito científico
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Régimen de financiación
ERC-COG - Consolidator GrantInstitución de acogida
75794 Paris
Francia