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Un aumento transitorio de la temperatura de la superficie del mar tropical durante el máximo térmico del
James C Zachos1, Michael W Wara, Steven Bohaty
1Earth and Ocean Sciences Departments, University of California, Santa Cruz, CA 95064, USA. jzachos@es.ucsc.edu
Science (New York, N.Y.)
|October 25, 2003
Resumen
El Máximo Térmico Paleoceno-Eoceno causó un calentamiento significativo de los océanos, con temperaturas de la superficie del mar en el Pacífico tropical que aumentaron entre 4 y 5°C. Este calentamiento sugiere niveles de dióxido de carbono atmosférico más altos de lo estimado anteriormente.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Oceanografía La oceanografía es la oceanografía.
- La geoquímica es la geoquímica.
Sus antecedentes:
- El Máximo Térmico Paleoceno-Eoceno (PETM) fue un período de rápido calentamiento global.
- Se esperaba un calentamiento en todas las latitudes, pero los cambios en la temperatura de la superficie del mar tropical (SST) no estaban restringidos.
- Los registros de altas latitudes muestran un SST significativo y un calentamiento del agua de fondo.
Objetivo del estudio:
- Para determinar la respuesta del SST tropical durante el PETM.
- Para limitar la magnitud del calentamiento en el Pacífico tropical.
- Para estimar el aumento asociado en el dióxido de carbono atmosférico (pCO2).
Principales métodos:
- Análisis de foraminíferos planctónicos de un núcleo de sedimentos del Pacífico tropical.
- Medidas de isótopos de oxígeno emparejados y mediciones de la relación magnesio/calcio.
- Reconstrucción de temperaturas pasadas de la superficie del mar utilizando proxies geoquímicos.
Principales resultados:
- Las SST del Pacífico Tropical aumentaron entre 4°C y 5°C durante el PETM.
- Este calentamiento es comparable a los aumentos de temperatura en latitudes altas.
- Los resultados indican un aumento sustancial en el pCO2 atmosférico2.
Conclusiones:
- Los océanos tropicales experimentaron un calentamiento significativo durante el PETM.
- El PETM fue impulsado por un aumento sustancial en el pCO2 atmosférico, posiblemente 3-4 veces más alto que los niveles del Paleoceno tardío.
- Los proxies geoquímicos de los foraminíferos son cruciales para reconstruir eventos climáticos pasados.
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