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地处典型东亚季风区的神农架大九湖盆地有华中地区面积最大、海拔最高的亚高山泥炭沼泽湿地。对盆地中心部位钻孔DJH-2中821～430cm泥炭沉积进行花粉浓缩物AMSC测年,经校正发现其沉积时段为59.8～26.1kaB.P,与MIS 3阶段相对应。研究显示,在MIS 3阶段研究区气候环境适宜植被的生长和有机质的保存,基于α-纤维素δ~(13)C重建的大气湿度显示平均为72%的湿度值总体略高于全新世晚期,且MIS 3早期(60～49kaB.P.)和晚期(38.5～26.1 kaB.P.)较高,大气湿度平均为75%和72%,中期(49.0～38.5kaB.P.)略低,平均69%,温度则由早期到晚期呈现逐渐降低趋势。高分辨率的泥炭记录显示千年尺度的气候变化呈现5个波动旋回,期间出现的4次冷干事件与H冷事件一一对应,并且存在多次暖(温)湿事件对应于D-O暖事件。此段沼泽沉积是大九湖对这一时期东亚夏季风强度明显增强的直接响应,与全球众多记录对比揭示出MIS 3阶段神农架泥炭记录在岁差尺度东亚夏季风环流强度主要受太阳辐射控制,其功率谱分析显示存在的多个显著周期为千年尺度上东亚夏季风强度主要受太阳输出量控制的观点提供了有力支持。
Located in the typical East Asian monsoon area, Shennongjia Great Jiuhu Basin has the largest and highest altitude subalpine peat wetlands in Central China. The AMSCs of 821 ~ 430cm peat sediment in the center of the basin were collected from a pollen concentration of 598 ~ 26.1kaB.P, which corresponded to the MIS 3 stage. The results showed that the average humidity of 72% in the atmospheric humidity based on α-cellulose δ ~ (13) C reconstruction was slightly higher than that of the late Holocene in the study area of MIS 3 in the climatic environment suitable for vegetation growth and organic matter preservation , And the MIS 3 in the early period (60 ~ 49kaB.P.) And late stage (38.5 ~ 26.1 kaB.P.) were higher, with the average of 75% and 72% of the atmospheric humidity, and slightly lower in the middle period (49.0 ~ 38.5kaB.P.) An average of 69%, the temperature from early to late showed a gradual downward trend. High-resolution peat records show five climatic cycles of climatic change on a thousand-year scale, with four cold events corresponding to H cold events one at a time, and multiple warm (warm) wet events corresponding to D-O warm events. This period of swamp deposition is a direct response of Daxiu Lake to the intensity of East Asian summer monsoon during this period. Comparing with many records across the world, it is revealed that MIS 3 stage Shennongjia peat is recorded in the precession scale. The intensity of the East Asian summer monsoon circulation is mainly controlled by solar radiation. Power spectrum analysis shows that there are several significant periods in existence that provide strong support for the view that the East Asian summer monsoon intensity is dominated by solar output at the millennium scale.