近千年亚洲季风变化驱动力的初步研究

通过反演方法,利用已有的影响亚洲季风变化的相应资料,通过动力模型建立了近千年亚洲季风变化的驱动力方程,根据各指标的具体数值反演出方程中各项系数和对应的贡献率。分析方程中各气候代用指标对亚洲季风变化的影响程度,发现近千年亚洲季风并非只受到这些气候要素的线性作用,而是受到较为复杂的非线性驱动力作用,其中大气中CO₂含量、印度洋海表温度、前一期季风强度、南方涛动指数、CH₄气体含量、格陵兰温度、北大西洋海表温度、北半球温度等在驱动近千年亚洲季风变化中起到较为重要的作用,而在长时间尺度上对季风变化有重要影响的太阳活动,近千年中其直接影响并不十分显著,这也可能是指标精度的原因。

Preliminary Study of the Driving Force on the Asian Monsoon Change During the Last Millennium

The Asian monsoon is an important part of the global climatic system. Previous studies have indicated that the formation and change of the Asian monsoon are greatly associated with solar activity, the land-sea thermal difference, global ice volume, the uplift of Qinghai-Tibet Plateau and other climatic and geographic elements. The proxies of the climate records are more abundant during the last millennium than those of the other history periods. The studies on the changes of the Asian monsoon during the last millennium can help us explore the monsoon evolution rules and predict tendency ofthe Asian monsoon in the future. In the paper, based on the inversion method and the currently available information and data, a driving model which probably reveals the dynamic mechanism of the Asian monsoon changes during the last millennium is established. According to the actual quantitative values of all the proxies, we can get the coefficients and the corresponding contribution rates of the equation. Through the analyses of the influencing degree of each climate proxy on the Asian monsoon, the following results are obtained: 1) The Asian monsoon is not only linearly affected by the climate elements, but also drived by a complex nonlinear dynamic system. 2) Some climate factors,including the concentration of carbon dioxide in the atmosphere, the Indian Ocean sea surface temperature, the previous monsoon intensity, southern oscillation index, methane content, the temperature of Greenland, the north Atlantic sea surface temperature and the northern hemisphere temperature, play important roles on the Asian monsoon changes during the last millennium. 3) The solar activity, which exhibits extremely important inpact on the Asian monsoon at long timescales, does not significantly affect the change of the Asian monsoon during the last millennium.