On the glacial-interglacial variability of the Asian monsoon in speleothem δ(18)O records

While Asian monsoon (AM) changes have been clearly captured in Chinese speleothem oxygen isotope (δ(18)O) records, the lack of glacial-interglacial variability in the records remains puzzling. Here, we report speleothem δ(18)O records from three locations along the trajectory of the Indian summer mo...

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Detalles Bibliográficos
Autores principales: Liu, G., Li, X., Chiang, H.-W., Cheng, H., Yuan, S., Chawchai, S., He, S., Lu, Y., Aung, L. T., Maung, P. M., Tun, W. N., Oo, K. M., Wang, X.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2020
Materias:
Research Articles
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7015693/
https://www.ncbi.nlm.nih.gov/pubmed/32095532
http://dx.doi.org/10.1126/sciadv.aay8189
Descripción
Sumario:While Asian monsoon (AM) changes have been clearly captured in Chinese speleothem oxygen isotope (δ(18)O) records, the lack of glacial-interglacial variability in the records remains puzzling. Here, we report speleothem δ(18)O records from three locations along the trajectory of the Indian summer monsoon (ISM), a major branch of the AM, and characterize AM rainfall over the past 180,000 years. We have found that the records close to the monsoon moisture source show large glacial-interglacial variability, which then decreases landward. These changes likely reflect a stronger oxygen isotope fractionation associated with progressive rainout of AM moisture during glacial periods, possibly due to a larger temperature gradient and suppressed plant transpiration. We term this effect, which counteracts the forcing of glacial boundary conditions, the moisture transport pathway effect.

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