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Registro de alta resolución del clima del hemisferio norte que se extiende hasta el último período interglacial
K K Andersen1, N Azuma, J-M Barnola
1Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen OE, Denmark.
Nature
|September 10, 2004
Resumen
Un nuevo núcleo de hielo del norte de Groenlandia revela un clima estable y más cálido durante el último período interglacial. Este registro detalla el inicio del último período glacial y un evento de calentamiento abrupto no reconocido.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Glaciología glaciología.
- Ciencias del clima Ciencias del clima Ciencias del clima
Sus antecedentes:
- Los núcleos de hielo del centro de Groenlandia son cruciales para las reconstrucciones climáticas del hemisferio norte.
- Las secciones más antiguas de estos núcleos tienen perturbaciones cronológicas debido al plegamiento del hielo.
- Se necesita un registro climático continuo y no perturbado del último período interglacial.
Objetivo del estudio:
- Para presentar un registro climático no perturbado de un núcleo de hielo del norte de Groenlandia que abarca el último período interglacial.
- Para reconstruir la temperatura y la estabilidad climática durante este período.
- Para investigar la dinámica del clima hemisférico y el inicio del último período glacial.
Principales métodos:
- Perforación y análisis de un núcleo de hielo profundo en el norte de Groenlandia.
- Análisis de isótopos de oxígeno para reconstruir temperaturas pasadas.
- Datación cronológica de las secciones del núcleo de hielo.
Principales resultados:
- Un registro climático inalterado que se remonta a 123.000 años antes del presente.
- Condiciones climáticas estables con temperaturas 5 ° C más cálidas que hoy durante el último período interglacial.
- Evidencia de un evento de calentamiento abrupto no reconocido previamente hace unos 115.000 años.
- Diferencias significativas de temperatura entre los registros del norte y el centro de Groenlandia, lo que sugiere que la extensión del hielo del hemisferio norte modula los gradientes de temperatura latitudinales.
- Un lento descenso de la temperatura que marca el comienzo del último período glacial.
- Falta de una contraparte antártica inmediata al evento de calentamiento abrupto, lo que indica una interacción climática hemisférica diferente.
Conclusiones:
- El último período interglacial se caracterizó por un clima estable y más cálido que el actual en Groenlandia.
- La extensión del hielo del hemisferio norte influyó en los gradientes de temperatura latitudinales de Groenlandia.
- Un evento de calentamiento abrupto no reconocido ocurrió antes del pleno desarrollo del último período glacial.
- El mecanismo interhemisférico de cambio climático puede no haber sido dominante durante esta transición específica.
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