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Un registro de alta resolución con fecha absoluta del monzón del Pleistoceno tardío de la cueva de Hulu, China
Y J Wang1, H Cheng, R L Edwards
1College of Geography Science, Nanjing Normal University, Nanjing 210097, China.
Science (New York, N.Y.)
|December 18, 2001
Resumen
Los registros de isótopos de oxígeno de estalagmita revelan que la intensidad del monzón del este de Asia sigue de cerca los cambios de temperatura de Groenlandia en los últimos 75.000 años. Esto sugiere un sistema climático vinculado entre el Atlántico Norte y el este de Asia.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Speleothem Ciencia de las ciencias.
- La dinámica del clima La dinámica del clima La dinámica del clima
Sus antecedentes:
- El análisis de isótopos de oxígeno de estalagmitas proporciona un sustituto de las condiciones climáticas pasadas.
- Los núcleos de hielo de Groenlandia ofrecen un registro bien establecido de las fluctuaciones de temperatura en el hemisferio norte.
- El monzón del este de Asia (EAM) juega un papel crítico en el clima regional y la hidrología.
Objetivo del estudio:
- Para investigar la relación entre la intensidad del monzón del este de Asia y las temperaturas de Groenlandia.
- Para comparar el tiempo de los eventos paleoclimáticos registrados en espeleotemas y núcleos de hielo.
- Explorar las teleconexiones entre el clima del Atlántico Norte y la dinámica de la EAM.
Principales métodos:
- Análisis de las proporciones de isótopos de oxígeno de cinco estalagmitas recogidas en la cueva de Hulu, Nanjing.
- Datación radiométrica utilizando uranio-torio (230Th) para establecer el control cronológico.
- Comparación de los datos de isótopos de estalagmita con los registros existentes de núcleos de hielo de Groenlandia (por ejemplo, Proyecto de capa de hielo de Groenlandia Dos - GISP2).
Principales resultados:
- Los registros de isótopos de oxígeno de estalagmita de la cueva de Hulu muestran una fuerte correlación con los registros de núcleos de hielo de Groenlandia.
- El tiempo de las variaciones del EAM, fechado en 230Th, se alinea con los cambios de temperatura en el núcleo de GISP2 entre 11.000 y 30.000 años antes del presente.
- Esta concordancia sugiere que la intensidad del EAM y las temperaturas de Groenlandia fluctuaron al unísono durante el período estudiado.
Conclusiones:
- El estudio demuestra un acoplamiento significativo entre el clima del Atlántico Norte (representado por las temperaturas de Groenlandia) y el monzón del este de Asia.
- El transporte meridional de calor y humedad de los océanos tropicales, la fuente del EAM, une estos sistemas climáticos geográficamente distantes.
- Los hallazgos apoyan la fiabilidad de las reconstrucciones paleoclimáticas y destacan la interconexión de los patrones climáticos globales.
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