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摘要
The development of climate reconstruction greatly promotes the study of Asian monsoon variability in the Holocene. However, the current reconstruction result on the characteristics and mechanisms of the Asian monsoon evolution remains controversial. Meanwhile, paleoclimate simulation can contribute significantly to the understanding of the temporal-spatial characteristics and genetic mechanisms of the Asian monsoon evolution in the Holocene. This paper reviews simulation studies on the centennial to millennial-scale Asian monsoon variations during the Holocene from the perspective of climate modeling, and discusses the mechanisms from the perspectives of external forcing and internal variability. Among the main progresses, the Holocene transient simulation results show a downward trend in the Asian monsoon precipitation since the early Holocene, which is thought to be affected mainly by the earth orbital parameters, as well as changes in land-sea thermal contrast and inter-hemispheric temperature gradient. For centennial-scale weak monsoons, simulation of a 8. 2 ka BP weak monsoon event reveals glacial melting water as the main trigger for the weakening of Atlantic meridional overturning circulation and atmospheric teleconnection; whilst simulation of a 4.2 ka BP weak monsoon event indicates such event may be controlled by internal variability rather than external forcing. Simulation studies on the centennial-scale changes mainly focus on the past 2 000 years. The results show an obvious increase of Asian monsoon precipitation during the Medieval Climate Anomaly but a gradual decrease during the Little Ice Age. Solar radiation and volcanic activity play a crucial role in centennial-scale Asian monsoon variations through influencing land-sea thermal contrast and Indo-Pacific sea surface temperature change.
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