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Temperaturas subtropicales del Atlántico Norte hace entre 60.000 y 30.000 años
1Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309-0450, USA.
Science (New York, N.Y.)
|October 26, 1999
Resumen
Las temperaturas de la superficie del mar en el norte del Mar de los Sargazos fluctuaron significativamente entre hace 60.000 y 30.000 años. Estos cambios climáticos subtropicales reflejaron los cambios en las regiones de alta latitud, lo que indica una dinámica climática vinculada.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Oceanografía La oceanografía es la oceanografía.
- Ciencias del clima Ciencias del clima Ciencias del clima Ciencias del clima
Sus antecedentes:
- Comprender la variabilidad climática pasada es crucial para predecir el cambio climático futuro.
- Los eventos climáticos de altas latitudes se han relacionado con los cambios climáticos subtropicales, pero la naturaleza precisa de esta relación requiere una mayor investigación.
Objetivo del estudio:
- Para reconstruir las temperaturas subtropicales de la superficie del mar (SSTs) durante un período crítico de la historia climática de la Tierra.
- Investigar la correlación entre los cambios climáticos subtropicales y los eventos climáticos de altas latitudes.
Principales métodos:
- Utilizó las proporciones de insaturación de alquenonas en las Bermudas para reconstruir los SST pasados.
- Estableció un registro detallado del paleoclima que abarca desde hace 60,000 a 30,000 años.
Principales resultados:
- Se han documentado repetidas fluctuaciones del SST de 2-5°C en el norte del Mar de los Sargazos.
- Se observó una fuerte covarianza entre estos cambios de temperatura subtropicales y las temperaturas de altas latitudes inferidas de los núcleos de hielo de Groenlandia.
- Se han identificado inversiones bruscas de frío de 3-5°C, que duran menos de 250 años, durante períodos interestadios específicos.
Conclusiones:
- Los mayores eventos de calentamiento en los subtrópicos fueron comparables en magnitud al calentamiento glacial-Holoceno.
- Los hallazgos sugieren que los rápidos eventos de calentamiento subtropical eran intrínsecamente inestables, propensos a inversiones bruscas de enfriamiento.
- Esto pone de relieve la interconexión de los sistemas climáticos globales y el potencial de cambios rápidos en respuesta al forzamiento de altas latitudes.
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