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Las restricciones de isótopos de carbono en el aumento de CO2 deglacial de los núcleos de hielo
Jochen Schmitt1, Robert Schneider, Joachim Elsig
1Climate and Environmental Physics, Physics Institute, and Oeschger Centre for Climate Change Research, University of Bern, CH-3012 Bern, Switzerland. schmitt@climate.unibe.ch
Science (New York, N.Y.)
|March 31, 2012
Resumen
La relación de isótopos de carbono estables del dióxido de carbono atmosférico (CO2) revela cambios pasados en el ciclo del carbono. La deglaciación temprana vio una disminución de isótopos de CO2 vinculada a la subida de aguas del Océano Antártico, con cambios posteriores impulsados por la biosfera y la dinámica oceánica.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- La geoquímica es la geoquímica.
- Ciencias del Sistema Terrestre Ciencias del Sistema Terrestre
Sus antecedentes:
- La relación de isótopos estables de carbono del CO2 atmosférico (δ) es crucial para comprender la dinámica del ciclo del carbono pasado.
- La reconstrucción de δ ((13) C ((atm) proporciona información sobre los depósitos y flujos globales de carbono.
Objetivo del estudio:
- Para presentar nuevos datos de δ(13) C(atm) que abarcan los últimos 24.000 años.
- Para investigar los impulsores de los cambios de isótopos atmosféricos de CO2 durante la última transición glacial-interglacial.
Principales métodos:
- Análisis de δ(13) C(atm) de tres registros independientes.
- Utilizando datos de dos núcleos de hielo de la Antártida.
Principales resultados:
- Una disminución significativa de 0,3 por mil en δ 13 C atm durante la deglaciación temprana.
- Identificación de la corriente ascendente del Océano Austral de aguas viejas enriquecidas con carbono como la causa principal de la disminución de la deglaciación temprana.
- Demostración de que el crecimiento de la biosfera terrestre, la temperatura de la superficie del mar y la circulación oceánica influyeron en la posterior evolución deglacial.
- Observación de las constantes δ(13) C(atm) y CO(2) durante el Último Máximo Glacial, indicando el equilibrio del ciclo del carbono.
Conclusiones:
- Los procesos del Océano Austral jugaron un papel clave en los primeros cambios del ciclo del carbono deglacial.
- La dinámica de la biosfera terrestre y del océano moduló los isótopos atmosféricos de CO2 más adelante en la deglaciación.
- El ciclo del carbono estaba en equilibrio dinámico durante el Último Máximo Glacial, con anterioridad al secuestro de carbono en las profundidades del océano.
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