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Forzamiento de precesión de la dinámica de la nutriclina en el Atlántico ecuatorial
Science (New York, N.Y.)
|August 17, 1990
Resumen
El control climático de la profundidad nutricline del Atlántico está relacionado con el fitoplancton Florisphaera profunda. Sus variaciones de abundancia se correlacionan con los cambios de profundidad de la nutriclina, influenciados por la insolación orbital y los vientos del este tropicales durante milenios.
Área de la Ciencia:
- La paleoceanografía es la paleoceanografía.
- Ecología del fitoplancton marino ecología del fitoplancton marino
- La dinámica del clima y su dinámica.
Sus antecedentes:
- La profundidad nutriclina en el Atlántico ecuatorial influye en los ecosistemas marinos.
- La abundancia de Florisphaera profunda es un indicador potencial de la profundidad de la nutriclina.
- Estudios previos sugieren un vínculo entre las variaciones climáticas y nutricionales.
Objetivo del estudio:
- Investigar la relación a largo plazo entre la abundancia de Florisphaera profunda y la profundidad de la nutriclina.
- Para determinar la influencia de la insolación orbital en el clima del Atlántico y la dinámica de la nutriclina.
- Para reconstruir la variabilidad climática pasada en el Atlántico ecuatorial.
Principales métodos:
- Análisis de un registro de núcleo de aguas profundas de 200.000 años de abundancias relativas de F. profunda.
- Análisis espectral cruzado con datos de temperatura de la superficie del mar derivados de especies de zooplancton.
- Correlación de los ciclos de F. profunda con los ciclos precesionales de la órbita de la Tierra.
Principales resultados:
- Un registro de 200.000 años muestra la varianza de F. profunda centrada en una banda de precesión de 23.000 años.
- Los ciclos de F. profunda son coherentes y en fase con los ciclos de temperatura de la superficie del mar.
- Las variaciones de abundancia se correlacionan con el tiempo del perihelio (diciembre y junio).
Conclusiones:
- La profundidad de la línea nutritiva en el Atlántico ecuatorial está controlada por las variaciones en el este tropical.
- Estas variaciones son forzadas por el componente de precesión de la insolación orbital.
- El control climático de la profundidad nutricline opera en escalas de tiempo superiores a 10.000 años.
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