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Registros de núcleos de hielo de N2O atmosférico que cubren los últimos 106.000 años

Todd Sowers¹, Richard B Alley, Jennifer Jubenville

¹Department of Geosciences and the EMS Environment Institute, Pennsylvania State University, UniversityPark, PA 16802, USA. sowers@geosc.psu.edu

Science (New York, N.Y.)

|August 16, 2003

Resumen

Los registros de núcleos de hielo revelan cambios en el óxido nitroso atmosférico (N2O) durante 106.000 años. Las emisiones de N2O de fuentes marinas y oceánicas aumentaron significativamente durante la última terminación glacial.

Área de la Ciencia:

Paleoclimatología Paleoclimatología
Ciclos biogeoquímicos y ciclos biogeoquímicos.
Química de la atmósfera química de la atmósfera

Sus antecedentes:

Los núcleos de hielo ofrecen datos paleoatmosféricos vitales sobre gases traza como el óxido nitroso (N2O).
Comprender el papel del N2O en los ciclos biogeoquímicos es crucial para los estudios climáticos.
Investigaciones anteriores han explorado los vínculos entre los gases de efecto invernadero y los períodos glaciales.

Objetivo del estudio:

Para reconstruir un registro de 106.000 años de concentraciones atmosféricas de N2O.
Para analizar los registros isotópicos de N2O durante los últimos 30.000 años.
Investigar los cambios en las proporciones de producción y emisiones de N2O marinas frente a las terrestres.

Principales métodos:

Análisis de las concentraciones de gases traza de muestras de núcleos de hielo.
Análisis de isótopos estables de N2O de los registros de núcleos de hielo.
Reconstrucción de los niveles de N2O paleoatmosféricos y la composición isotópica.

Principales resultados:

Se estableció un registro de N2O atmosférico de 106.000 años.
Los registros isotópicos indican cambios mínimos en la relación de producción de N2O marino/terrestre.
Las emisiones marinas y oceánicas de N2O aumentaron en un 40% durante la última terminación glacial.

Conclusiones:

El estudio sugiere contribuciones relativas estables de fuentes marinas y terrestres de N2O en escalas de tiempo largas.
Los aumentos observados en las emisiones de N2O durante la deglaciación pueden no ser impulsados únicamente por una mayor producción oceánica de exportación.
Los hallazgos proporcionan nuevos conocimientos sobre la dinámica del N2O oceánico y terrestre durante las transiciones climáticas pasadas.

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