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Restricciones sobre la duración y liberación de agua dulce del evento 4 de Heinrich a través del modelado isotópico
D Roche1, D Paillard, E Cortijo
1IPSL/Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS, 91191 Gif sur Yvette, France. roche@lsce.saclay.cea.fr
Nature
|November 19, 2004
Resumen
Los eventos de Heinrich fueron episodios abruptos de enfriamiento del clima. Una nueva investigación sobre el evento 4 de Heinrich sugiere que fueron más cortos y liberaron menos hielo de lo que se pensaba anteriormente, lo que podría disminuir su impacto climático.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Modelado del clima en el modelo climático.
- Oceanografía La oceanografía es la oceanografía.
Sus antecedentes:
- Los eventos de Heinrich son eventos abruptos de enfriamiento del clima durante los períodos glaciales, vinculados a la inestabilidad de la capa de hielo en el Atlántico Norte.
- Si bien se han modelado los mecanismos físicos, las características cuantitativas de los eventos de Heinrich siguen siendo poco conocidas.
Objetivo del estudio:
- Para simular el evento 4 de Heinrich (aprox. 40.000 años atrás) utilizando un modelo climático de complejidad intermedia.
- Para refinar las estimaciones cuantitativas para la duración y la liberación de hielo del evento Heinrich 4.
Principales métodos:
- Utilizó un modelo climático que incorpora la distribución de isótopos de oxígeno en el océano.
- Comparó simulaciones de modelos con datos de isótopos de oxígeno de calcita foraminiferal en núcleos de sedimentos del Atlántico Norte.
Principales resultados:
- Determinó que la duración del evento 4 de Heinrich sería de 250 +/- 150 años.
- Liberación de hielo cuantificada para el evento 4 de Heinrich a 2 +/- 1 m equivalente a nivel del mar.
- Incertidumbre significativamente reducida en comparación con las estimaciones anteriores (hasta 2.000 años y 15 m equivalente al nivel del mar).
Conclusiones:
- El evento 4 de Heinrich fue más corto e involucró menos liberación de hielo de lo estimado previamente.
- Los impactos climáticos y del nivel del mar de los eventos de Heinrich pueden haber sido menos severos de lo que se suponía anteriormente.
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